in sqlite/sqlite3_retail.c [109494:150247]
static void decodeIntArray(
char *zIntArray, /* String containing int array to decode */
int nOut, /* Number of slots in aOut[] */
tRowcnt *aOut, /* Store integers here */
LogEst *aLog, /* Or, if aOut==0, here */
Index *pIndex /* Handle extra flags for this index, if not NULL */
){
char *z = zIntArray;
int c;
int i;
tRowcnt v;
#ifdef SQLITE_ENABLE_STAT4
if( z==0 ) z = "";
#else
assert( z!=0 );
#endif
for(i=0; *z && i<nOut; i++){
v = 0;
while( (c=z[0])>='0' && c<='9' ){
v = v*10 + c - '0';
z++;
}
#ifdef SQLITE_ENABLE_STAT4
if( aOut ) aOut[i] = v;
if( aLog ) aLog[i] = sqlite3LogEst(v);
#else
assert( aOut==0 );
UNUSED_PARAMETER(aOut);
assert( aLog!=0 );
aLog[i] = sqlite3LogEst(v);
#endif
if( *z==' ' ) z++;
}
#ifndef SQLITE_ENABLE_STAT4
assert( pIndex!=0 ); {
#else
if( pIndex ){
#endif
pIndex->bUnordered = 0;
pIndex->noSkipScan = 0;
while( z[0] ){
if( sqlite3_strglob("unordered*", z)==0 ){
pIndex->bUnordered = 1;
}else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){
int sz = sqlite3Atoi(z+3);
if( sz<2 ) sz = 2;
pIndex->szIdxRow = sqlite3LogEst(sz);
}else if( sqlite3_strglob("noskipscan*", z)==0 ){
pIndex->noSkipScan = 1;
}
#ifdef SQLITE_ENABLE_COSTMULT
else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){
pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9));
}
#endif
while( z[0]!=0 && z[0]!=' ' ) z++;
while( z[0]==' ' ) z++;
}
}
}
/*
** This callback is invoked once for each index when reading the
** sqlite_stat1 table.
**
** argv[0] = name of the table
** argv[1] = name of the index (might be NULL)
** argv[2] = results of analysis - on integer for each column
**
** Entries for which argv[1]==NULL simply record the number of rows in
** the table.
*/
static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
analysisInfo *pInfo = (analysisInfo*)pData;
Index *pIndex;
Table *pTable;
const char *z;
assert( argc==3 );
UNUSED_PARAMETER2(NotUsed, argc);
if( argv==0 || argv[0]==0 || argv[2]==0 ){
return 0;
}
pTable = sqlite3FindTable(pInfo->db, argv[0], pInfo->zDatabase);
if( pTable==0 ){
return 0;
}
if( argv[1]==0 ){
pIndex = 0;
}else if( sqlite3_stricmp(argv[0],argv[1])==0 ){
pIndex = sqlite3PrimaryKeyIndex(pTable);
}else{
pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase);
}
z = argv[2];
if( pIndex ){
tRowcnt *aiRowEst = 0;
int nCol = pIndex->nKeyCol+1;
#ifdef SQLITE_ENABLE_STAT4
/* Index.aiRowEst may already be set here if there are duplicate
** sqlite_stat1 entries for this index. In that case just clobber
** the old data with the new instead of allocating a new array. */
if( pIndex->aiRowEst==0 ){
pIndex->aiRowEst = (tRowcnt*)sqlite3MallocZero(sizeof(tRowcnt) * nCol);
if( pIndex->aiRowEst==0 ) sqlite3OomFault(pInfo->db);
}
aiRowEst = pIndex->aiRowEst;
#endif
pIndex->bUnordered = 0;
decodeIntArray((char*)z, nCol, aiRowEst, pIndex->aiRowLogEst, pIndex);
pIndex->hasStat1 = 1;
if( pIndex->pPartIdxWhere==0 ){
pTable->nRowLogEst = pIndex->aiRowLogEst[0];
pTable->tabFlags |= TF_HasStat1;
}
}else{
Index fakeIdx;
fakeIdx.szIdxRow = pTable->szTabRow;
#ifdef SQLITE_ENABLE_COSTMULT
fakeIdx.pTable = pTable;
#endif
decodeIntArray((char*)z, 1, 0, &pTable->nRowLogEst, &fakeIdx);
pTable->szTabRow = fakeIdx.szIdxRow;
pTable->tabFlags |= TF_HasStat1;
}
return 0;
}
/*
** If the Index.aSample variable is not NULL, delete the aSample[] array
** and its contents.
*/
SQLITE_PRIVATE void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){
#ifdef SQLITE_ENABLE_STAT4
if( pIdx->aSample ){
int j;
for(j=0; j<pIdx->nSample; j++){
IndexSample *p = &pIdx->aSample[j];
sqlite3DbFree(db, p->p);
}
sqlite3DbFree(db, pIdx->aSample);
}
if( db && db->pnBytesFreed==0 ){
pIdx->nSample = 0;
pIdx->aSample = 0;
}
#else
UNUSED_PARAMETER(db);
UNUSED_PARAMETER(pIdx);
#endif /* SQLITE_ENABLE_STAT4 */
}
#ifdef SQLITE_ENABLE_STAT4
/*
** Populate the pIdx->aAvgEq[] array based on the samples currently
** stored in pIdx->aSample[].
*/
static void initAvgEq(Index *pIdx){
if( pIdx ){
IndexSample *aSample = pIdx->aSample;
IndexSample *pFinal = &aSample[pIdx->nSample-1];
int iCol;
int nCol = 1;
if( pIdx->nSampleCol>1 ){
/* If this is stat4 data, then calculate aAvgEq[] values for all
** sample columns except the last. The last is always set to 1, as
** once the trailing PK fields are considered all index keys are
** unique. */
nCol = pIdx->nSampleCol-1;
pIdx->aAvgEq[nCol] = 1;
}
for(iCol=0; iCol<nCol; iCol++){
int nSample = pIdx->nSample;
int i; /* Used to iterate through samples */
tRowcnt sumEq = 0; /* Sum of the nEq values */
tRowcnt avgEq = 0;
tRowcnt nRow; /* Number of rows in index */
i64 nSum100 = 0; /* Number of terms contributing to sumEq */
i64 nDist100; /* Number of distinct values in index */
if( !pIdx->aiRowEst || iCol>=pIdx->nKeyCol || pIdx->aiRowEst[iCol+1]==0 ){
nRow = pFinal->anLt[iCol];
nDist100 = (i64)100 * pFinal->anDLt[iCol];
nSample--;
}else{
nRow = pIdx->aiRowEst[0];
nDist100 = ((i64)100 * pIdx->aiRowEst[0]) / pIdx->aiRowEst[iCol+1];
}
pIdx->nRowEst0 = nRow;
/* Set nSum to the number of distinct (iCol+1) field prefixes that
** occur in the stat4 table for this index. Set sumEq to the sum of
** the nEq values for column iCol for the same set (adding the value
** only once where there exist duplicate prefixes). */
for(i=0; i<nSample; i++){
if( i==(pIdx->nSample-1)
|| aSample[i].anDLt[iCol]!=aSample[i+1].anDLt[iCol]
){
sumEq += aSample[i].anEq[iCol];
nSum100 += 100;
}
}
if( nDist100>nSum100 && sumEq<nRow ){
avgEq = ((i64)100 * (nRow - sumEq))/(nDist100 - nSum100);
}
if( avgEq==0 ) avgEq = 1;
pIdx->aAvgEq[iCol] = avgEq;
}
}
}
/*
** Look up an index by name. Or, if the name of a WITHOUT ROWID table
** is supplied instead, find the PRIMARY KEY index for that table.
*/
static Index *findIndexOrPrimaryKey(
sqlite3 *db,
const char *zName,
const char *zDb
){
Index *pIdx = sqlite3FindIndex(db, zName, zDb);
if( pIdx==0 ){
Table *pTab = sqlite3FindTable(db, zName, zDb);
if( pTab && !HasRowid(pTab) ) pIdx = sqlite3PrimaryKeyIndex(pTab);
}
return pIdx;
}
/*
** Load the content from either the sqlite_stat4
** into the relevant Index.aSample[] arrays.
**
** Arguments zSql1 and zSql2 must point to SQL statements that return
** data equivalent to the following:
**
** zSql1: SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx
** zSql2: SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4
**
** where %Q is replaced with the database name before the SQL is executed.
*/
static int loadStatTbl(
sqlite3 *db, /* Database handle */
const char *zSql1, /* SQL statement 1 (see above) */
const char *zSql2, /* SQL statement 2 (see above) */
const char *zDb /* Database name (e.g. "main") */
){
int rc; /* Result codes from subroutines */
sqlite3_stmt *pStmt = 0; /* An SQL statement being run */
char *zSql; /* Text of the SQL statement */
Index *pPrevIdx = 0; /* Previous index in the loop */
IndexSample *pSample; /* A slot in pIdx->aSample[] */
assert( db->lookaside.bDisable );
zSql = sqlite3MPrintf(db, zSql1, zDb);
if( !zSql ){
return SQLITE_NOMEM_BKPT;
}
rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
sqlite3DbFree(db, zSql);
if( rc ) return rc;
while( sqlite3_step(pStmt)==SQLITE_ROW ){
int nIdxCol = 1; /* Number of columns in stat4 records */
char *zIndex; /* Index name */
Index *pIdx; /* Pointer to the index object */
int nSample; /* Number of samples */
int nByte; /* Bytes of space required */
int i; /* Bytes of space required */
tRowcnt *pSpace;
zIndex = (char *)sqlite3_column_text(pStmt, 0);
if( zIndex==0 ) continue;
nSample = sqlite3_column_int(pStmt, 1);
pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);
assert( pIdx==0 || pIdx->nSample==0 );
if( pIdx==0 ) continue;
assert( !HasRowid(pIdx->pTable) || pIdx->nColumn==pIdx->nKeyCol+1 );
if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){
nIdxCol = pIdx->nKeyCol;
}else{
nIdxCol = pIdx->nColumn;
}
pIdx->nSampleCol = nIdxCol;
nByte = sizeof(IndexSample) * nSample;
nByte += sizeof(tRowcnt) * nIdxCol * 3 * nSample;
nByte += nIdxCol * sizeof(tRowcnt); /* Space for Index.aAvgEq[] */
pIdx->aSample = sqlite3DbMallocZero(db, nByte);
if( pIdx->aSample==0 ){
sqlite3_finalize(pStmt);
return SQLITE_NOMEM_BKPT;
}
pSpace = (tRowcnt*)&pIdx->aSample[nSample];
pIdx->aAvgEq = pSpace; pSpace += nIdxCol;
pIdx->pTable->tabFlags |= TF_HasStat4;
for(i=0; i<nSample; i++){
pIdx->aSample[i].anEq = pSpace; pSpace += nIdxCol;
pIdx->aSample[i].anLt = pSpace; pSpace += nIdxCol;
pIdx->aSample[i].anDLt = pSpace; pSpace += nIdxCol;
}
assert( ((u8*)pSpace)-nByte==(u8*)(pIdx->aSample) );
}
rc = sqlite3_finalize(pStmt);
if( rc ) return rc;
zSql = sqlite3MPrintf(db, zSql2, zDb);
if( !zSql ){
return SQLITE_NOMEM_BKPT;
}
rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
sqlite3DbFree(db, zSql);
if( rc ) return rc;
while( sqlite3_step(pStmt)==SQLITE_ROW ){
char *zIndex; /* Index name */
Index *pIdx; /* Pointer to the index object */
int nCol = 1; /* Number of columns in index */
zIndex = (char *)sqlite3_column_text(pStmt, 0);
if( zIndex==0 ) continue;
pIdx = findIndexOrPrimaryKey(db, zIndex, zDb);
if( pIdx==0 ) continue;
/* This next condition is true if data has already been loaded from
** the sqlite_stat4 table. */
nCol = pIdx->nSampleCol;
if( pIdx!=pPrevIdx ){
initAvgEq(pPrevIdx);
pPrevIdx = pIdx;
}
pSample = &pIdx->aSample[pIdx->nSample];
decodeIntArray((char*)sqlite3_column_text(pStmt,1),nCol,pSample->anEq,0,0);
decodeIntArray((char*)sqlite3_column_text(pStmt,2),nCol,pSample->anLt,0,0);
decodeIntArray((char*)sqlite3_column_text(pStmt,3),nCol,pSample->anDLt,0,0);
/* Take a copy of the sample. Add two 0x00 bytes the end of the buffer.
** This is in case the sample record is corrupted. In that case, the
** sqlite3VdbeRecordCompare() may read up to two varints past the
** end of the allocated buffer before it realizes it is dealing with
** a corrupt record. Adding the two 0x00 bytes prevents this from causing
** a buffer overread. */
pSample->n = sqlite3_column_bytes(pStmt, 4);
pSample->p = sqlite3DbMallocZero(db, pSample->n + 2);
if( pSample->p==0 ){
sqlite3_finalize(pStmt);
return SQLITE_NOMEM_BKPT;
}
if( pSample->n ){
memcpy(pSample->p, sqlite3_column_blob(pStmt, 4), pSample->n);
}
pIdx->nSample++;
}
rc = sqlite3_finalize(pStmt);
if( rc==SQLITE_OK ) initAvgEq(pPrevIdx);
return rc;
}
/*
** Load content from the sqlite_stat4 table into
** the Index.aSample[] arrays of all indices.
*/
static int loadStat4(sqlite3 *db, const char *zDb){
int rc = SQLITE_OK; /* Result codes from subroutines */
assert( db->lookaside.bDisable );
if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){
rc = loadStatTbl(db,
"SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx",
"SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4",
zDb
);
}
return rc;
}
#endif /* SQLITE_ENABLE_STAT4 */
/*
** Load the content of the sqlite_stat1 and sqlite_stat4 tables. The
** contents of sqlite_stat1 are used to populate the Index.aiRowEst[]
** arrays. The contents of sqlite_stat4 are used to populate the
** Index.aSample[] arrays.
**
** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR
** is returned. In this case, even if SQLITE_ENABLE_STAT4 was defined
** during compilation and the sqlite_stat4 table is present, no data is
** read from it.
**
** If SQLITE_ENABLE_STAT4 was defined during compilation and the
** sqlite_stat4 table is not present in the database, SQLITE_ERROR is
** returned. However, in this case, data is read from the sqlite_stat1
** table (if it is present) before returning.
**
** If an OOM error occurs, this function always sets db->mallocFailed.
** This means if the caller does not care about other errors, the return
** code may be ignored.
*/
SQLITE_PRIVATE int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
analysisInfo sInfo;
HashElem *i;
char *zSql;
int rc = SQLITE_OK;
Schema *pSchema = db->aDb[iDb].pSchema;
assert( iDb>=0 && iDb<db->nDb );
assert( db->aDb[iDb].pBt!=0 );
/* Clear any prior statistics */
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
for(i=sqliteHashFirst(&pSchema->tblHash); i; i=sqliteHashNext(i)){
Table *pTab = sqliteHashData(i);
pTab->tabFlags &= ~TF_HasStat1;
}
for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){
Index *pIdx = sqliteHashData(i);
pIdx->hasStat1 = 0;
#ifdef SQLITE_ENABLE_STAT4
sqlite3DeleteIndexSamples(db, pIdx);
pIdx->aSample = 0;
#endif
}
/* Load new statistics out of the sqlite_stat1 table */
sInfo.db = db;
sInfo.zDatabase = db->aDb[iDb].zDbSName;
if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)!=0 ){
zSql = sqlite3MPrintf(db,
"SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase);
if( zSql==0 ){
rc = SQLITE_NOMEM_BKPT;
}else{
rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0);
sqlite3DbFree(db, zSql);
}
}
/* Set appropriate defaults on all indexes not in the sqlite_stat1 table */
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){
Index *pIdx = sqliteHashData(i);
if( !pIdx->hasStat1 ) sqlite3DefaultRowEst(pIdx);
}
/* Load the statistics from the sqlite_stat4 table. */
#ifdef SQLITE_ENABLE_STAT4
if( rc==SQLITE_OK ){
DisableLookaside;
rc = loadStat4(db, sInfo.zDatabase);
EnableLookaside;
}
for(i=sqliteHashFirst(&pSchema->idxHash); i; i=sqliteHashNext(i)){
Index *pIdx = sqliteHashData(i);
sqlite3_free(pIdx->aiRowEst);
pIdx->aiRowEst = 0;
}
#endif
if( rc==SQLITE_NOMEM ){
sqlite3OomFault(db);
}
return rc;
}
#endif /* SQLITE_OMIT_ANALYZE */
/************** End of analyze.c *********************************************/
/************** Begin file attach.c ******************************************/
/*
** 2003 April 6
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the ATTACH and DETACH commands.
*/
/* #include "sqliteInt.h" */
#ifndef SQLITE_OMIT_ATTACH
/*
** Resolve an expression that was part of an ATTACH or DETACH statement. This
** is slightly different from resolving a normal SQL expression, because simple
** identifiers are treated as strings, not possible column names or aliases.
**
** i.e. if the parser sees:
**
** ATTACH DATABASE abc AS def
**
** it treats the two expressions as literal strings 'abc' and 'def' instead of
** looking for columns of the same name.
**
** This only applies to the root node of pExpr, so the statement:
**
** ATTACH DATABASE abc||def AS 'db2'
**
** will fail because neither abc or def can be resolved.
*/
static int resolveAttachExpr(NameContext *pName, Expr *pExpr)
{
int rc = SQLITE_OK;
if( pExpr ){
if( pExpr->op!=TK_ID ){
rc = sqlite3ResolveExprNames(pName, pExpr);
}else{
pExpr->op = TK_STRING;
}
}
return rc;
}
/*
** Return true if zName points to a name that may be used to refer to
** database iDb attached to handle db.
*/
SQLITE_PRIVATE int sqlite3DbIsNamed(sqlite3 *db, int iDb, const char *zName){
return (
sqlite3StrICmp(db->aDb[iDb].zDbSName, zName)==0
|| (iDb==0 && sqlite3StrICmp("main", zName)==0)
);
}
/*
** An SQL user-function registered to do the work of an ATTACH statement. The
** three arguments to the function come directly from an attach statement:
**
** ATTACH DATABASE x AS y KEY z
**
** SELECT sqlite_attach(x, y, z)
**
** If the optional "KEY z" syntax is omitted, an SQL NULL is passed as the
** third argument.
**
** If the db->init.reopenMemdb flags is set, then instead of attaching a
** new database, close the database on db->init.iDb and reopen it as an
** empty MemDB.
*/
static void attachFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
int i;
int rc = 0;
sqlite3 *db = sqlite3_context_db_handle(context);
const char *zName;
const char *zFile;
char *zPath = 0;
char *zErr = 0;
unsigned int flags;
Db *aNew; /* New array of Db pointers */
Db *pNew; /* Db object for the newly attached database */
char *zErrDyn = 0;
sqlite3_vfs *pVfs;
UNUSED_PARAMETER(NotUsed);
zFile = (const char *)sqlite3_value_text(argv[0]);
zName = (const char *)sqlite3_value_text(argv[1]);
if( zFile==0 ) zFile = "";
if( zName==0 ) zName = "";
#ifdef SQLITE_ENABLE_DESERIALIZE
# define REOPEN_AS_MEMDB(db) (db->init.reopenMemdb)
#else
# define REOPEN_AS_MEMDB(db) (0)
#endif
if( REOPEN_AS_MEMDB(db) ){
/* This is not a real ATTACH. Instead, this routine is being called
** from sqlite3_deserialize() to close database db->init.iDb and
** reopen it as a MemDB */
pVfs = sqlite3_vfs_find("memdb");
if( pVfs==0 ) return;
pNew = &db->aDb[db->init.iDb];
if( pNew->pBt ) sqlite3BtreeClose(pNew->pBt);
pNew->pBt = 0;
pNew->pSchema = 0;
rc = sqlite3BtreeOpen(pVfs, "x\0", db, &pNew->pBt, 0, SQLITE_OPEN_MAIN_DB);
}else{
/* This is a real ATTACH
**
** Check for the following errors:
**
** * Too many attached databases,
** * Transaction currently open
** * Specified database name already being used.
*/
if( db->nDb>=db->aLimit[SQLITE_LIMIT_ATTACHED]+2 ){
zErrDyn = sqlite3MPrintf(db, "too many attached databases - max %d",
db->aLimit[SQLITE_LIMIT_ATTACHED]
);
goto attach_error;
}
for(i=0; i<db->nDb; i++){
assert( zName );
if( sqlite3DbIsNamed(db, i, zName) ){
zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName);
goto attach_error;
}
}
/* Allocate the new entry in the db->aDb[] array and initialize the schema
** hash tables.
*/
if( db->aDb==db->aDbStatic ){
aNew = sqlite3DbMallocRawNN(db, sizeof(db->aDb[0])*3 );
if( aNew==0 ) return;
memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
}else{
aNew = sqlite3DbRealloc(db, db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
if( aNew==0 ) return;
}
db->aDb = aNew;
pNew = &db->aDb[db->nDb];
memset(pNew, 0, sizeof(*pNew));
/* Open the database file. If the btree is successfully opened, use
** it to obtain the database schema. At this point the schema may
** or may not be initialized.
*/
flags = db->openFlags;
rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
if( rc!=SQLITE_OK ){
if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
sqlite3_result_error(context, zErr, -1);
sqlite3_free(zErr);
return;
}
assert( pVfs );
flags |= SQLITE_OPEN_MAIN_DB;
rc = sqlite3BtreeOpen(pVfs, zPath, db, &pNew->pBt, 0, flags);
db->nDb++;
pNew->zDbSName = sqlite3DbStrDup(db, zName);
}
db->noSharedCache = 0;
if( rc==SQLITE_CONSTRAINT ){
rc = SQLITE_ERROR;
zErrDyn = sqlite3MPrintf(db, "database is already attached");
}else if( rc==SQLITE_OK ){
Pager *pPager;
pNew->pSchema = sqlite3SchemaGet(db, pNew->pBt);
if( !pNew->pSchema ){
rc = SQLITE_NOMEM_BKPT;
}else if( pNew->pSchema->file_format && pNew->pSchema->enc!=ENC(db) ){
zErrDyn = sqlite3MPrintf(db,
"attached databases must use the same text encoding as main database");
rc = SQLITE_ERROR;
}
sqlite3BtreeEnter(pNew->pBt);
pPager = sqlite3BtreePager(pNew->pBt);
sqlite3PagerLockingMode(pPager, db->dfltLockMode);
sqlite3BtreeSecureDelete(pNew->pBt,
sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
sqlite3BtreeSetPagerFlags(pNew->pBt,
PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));
#endif
sqlite3BtreeLeave(pNew->pBt);
}
pNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
if( rc==SQLITE_OK && pNew->zDbSName==0 ){
rc = SQLITE_NOMEM_BKPT;
}
sqlite3_free_filename( zPath );
/* If the file was opened successfully, read the schema for the new database.
** If this fails, or if opening the file failed, then close the file and
** remove the entry from the db->aDb[] array. i.e. put everything back the
** way we found it.
*/
if( rc==SQLITE_OK ){
sqlite3BtreeEnterAll(db);
db->init.iDb = 0;
db->mDbFlags &= ~(DBFLAG_SchemaKnownOk);
if( !REOPEN_AS_MEMDB(db) ){
rc = sqlite3Init(db, &zErrDyn);
}
sqlite3BtreeLeaveAll(db);
assert( zErrDyn==0 || rc!=SQLITE_OK );
}
#ifdef SQLITE_USER_AUTHENTICATION
if( rc==SQLITE_OK && !REOPEN_AS_MEMDB(db) ){
u8 newAuth = 0;
rc = sqlite3UserAuthCheckLogin(db, zName, &newAuth);
if( newAuth<db->auth.authLevel ){
rc = SQLITE_AUTH_USER;
}
}
#endif
if( rc ){
if( !REOPEN_AS_MEMDB(db) ){
int iDb = db->nDb - 1;
assert( iDb>=2 );
if( db->aDb[iDb].pBt ){
sqlite3BtreeClose(db->aDb[iDb].pBt);
db->aDb[iDb].pBt = 0;
db->aDb[iDb].pSchema = 0;
}
sqlite3ResetAllSchemasOfConnection(db);
db->nDb = iDb;
if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
sqlite3OomFault(db);
sqlite3DbFree(db, zErrDyn);
zErrDyn = sqlite3MPrintf(db, "out of memory");
}else if( zErrDyn==0 ){
zErrDyn = sqlite3MPrintf(db, "unable to open database: %s", zFile);
}
}
goto attach_error;
}
return;
attach_error:
/* Return an error if we get here */
if( zErrDyn ){
sqlite3_result_error(context, zErrDyn, -1);
sqlite3DbFree(db, zErrDyn);
}
if( rc ) sqlite3_result_error_code(context, rc);
}
/*
** An SQL user-function registered to do the work of an DETACH statement. The
** three arguments to the function come directly from a detach statement:
**
** DETACH DATABASE x
**
** SELECT sqlite_detach(x)
*/
static void detachFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
const char *zName = (const char *)sqlite3_value_text(argv[0]);
sqlite3 *db = sqlite3_context_db_handle(context);
int i;
Db *pDb = 0;
HashElem *pEntry;
char zErr[128];
UNUSED_PARAMETER(NotUsed);
if( zName==0 ) zName = "";
for(i=0; i<db->nDb; i++){
pDb = &db->aDb[i];
if( pDb->pBt==0 ) continue;
if( sqlite3DbIsNamed(db, i, zName) ) break;
}
if( i>=db->nDb ){
sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName);
goto detach_error;
}
if( i<2 ){
sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName);
goto detach_error;
}
if( sqlite3BtreeTxnState(pDb->pBt)!=SQLITE_TXN_NONE
|| sqlite3BtreeIsInBackup(pDb->pBt)
){
sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName);
goto detach_error;
}
/* If any TEMP triggers reference the schema being detached, move those
** triggers to reference the TEMP schema itself. */
assert( db->aDb[1].pSchema );
pEntry = sqliteHashFirst(&db->aDb[1].pSchema->trigHash);
while( pEntry ){
Trigger *pTrig = (Trigger*)sqliteHashData(pEntry);
if( pTrig->pTabSchema==pDb->pSchema ){
pTrig->pTabSchema = pTrig->pSchema;
}
pEntry = sqliteHashNext(pEntry);
}
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
pDb->pSchema = 0;
sqlite3CollapseDatabaseArray(db);
return;
detach_error:
sqlite3_result_error(context, zErr, -1);
}
/*
** This procedure generates VDBE code for a single invocation of either the
** sqlite_detach() or sqlite_attach() SQL user functions.
*/
static void codeAttach(
Parse *pParse, /* The parser context */
int type, /* Either SQLITE_ATTACH or SQLITE_DETACH */
FuncDef const *pFunc,/* FuncDef wrapper for detachFunc() or attachFunc() */
Expr *pAuthArg, /* Expression to pass to authorization callback */
Expr *pFilename, /* Name of database file */
Expr *pDbname, /* Name of the database to use internally */
Expr *pKey /* Database key for encryption extension */
){
int rc;
NameContext sName;
Vdbe *v;
sqlite3* db = pParse->db;
int regArgs;
if( pParse->nErr ) goto attach_end;
memset(&sName, 0, sizeof(NameContext));
sName.pParse = pParse;
if(
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) ||
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) ||
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey))
){
goto attach_end;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
if( pAuthArg ){
char *zAuthArg;
if( pAuthArg->op==TK_STRING ){
zAuthArg = pAuthArg->u.zToken;
}else{
zAuthArg = 0;
}
rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);
if(rc!=SQLITE_OK ){
goto attach_end;
}
}
#endif /* SQLITE_OMIT_AUTHORIZATION */
v = sqlite3GetVdbe(pParse);
regArgs = sqlite3GetTempRange(pParse, 4);
sqlite3ExprCode(pParse, pFilename, regArgs);
sqlite3ExprCode(pParse, pDbname, regArgs+1);
sqlite3ExprCode(pParse, pKey, regArgs+2);
assert( v || db->mallocFailed );
if( v ){
sqlite3VdbeAddFunctionCall(pParse, 0, regArgs+3-pFunc->nArg, regArgs+3,
pFunc->nArg, pFunc, 0);
/* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
** statement only). For DETACH, set it to false (expire all existing
** statements).
*/
sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));
}
attach_end:
sqlite3ExprDelete(db, pFilename);
sqlite3ExprDelete(db, pDbname);
sqlite3ExprDelete(db, pKey);
}
/*
** Called by the parser to compile a DETACH statement.
**
** DETACH pDbname
*/
SQLITE_PRIVATE void sqlite3Detach(Parse *pParse, Expr *pDbname){
static const FuncDef detach_func = {
1, /* nArg */
SQLITE_UTF8, /* funcFlags */
0, /* pUserData */
0, /* pNext */
detachFunc, /* xSFunc */
0, /* xFinalize */
0, 0, /* xValue, xInverse */
"sqlite_detach", /* zName */
{0}
};
codeAttach(pParse, SQLITE_DETACH, &detach_func, pDbname, 0, 0, pDbname);
}
/*
** Called by the parser to compile an ATTACH statement.
**
** ATTACH p AS pDbname KEY pKey
*/
SQLITE_PRIVATE void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *pKey){
static const FuncDef attach_func = {
3, /* nArg */
SQLITE_UTF8, /* funcFlags */
0, /* pUserData */
0, /* pNext */
attachFunc, /* xSFunc */
0, /* xFinalize */
0, 0, /* xValue, xInverse */
"sqlite_attach", /* zName */
{0}
};
codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey);
}
#endif /* SQLITE_OMIT_ATTACH */
/*
** Initialize a DbFixer structure. This routine must be called prior
** to passing the structure to one of the sqliteFixAAAA() routines below.
*/
SQLITE_PRIVATE void sqlite3FixInit(
DbFixer *pFix, /* The fixer to be initialized */
Parse *pParse, /* Error messages will be written here */
int iDb, /* This is the database that must be used */
const char *zType, /* "view", "trigger", or "index" */
const Token *pName /* Name of the view, trigger, or index */
){
sqlite3 *db;
db = pParse->db;
assert( db->nDb>iDb );
pFix->pParse = pParse;
pFix->zDb = db->aDb[iDb].zDbSName;
pFix->pSchema = db->aDb[iDb].pSchema;
pFix->zType = zType;
pFix->pName = pName;
pFix->bTemp = (iDb==1);
}
/*
** The following set of routines walk through the parse tree and assign
** a specific database to all table references where the database name
** was left unspecified in the original SQL statement. The pFix structure
** must have been initialized by a prior call to sqlite3FixInit().
**
** These routines are used to make sure that an index, trigger, or
** view in one database does not refer to objects in a different database.
** (Exception: indices, triggers, and views in the TEMP database are
** allowed to refer to anything.) If a reference is explicitly made
** to an object in a different database, an error message is added to
** pParse->zErrMsg and these routines return non-zero. If everything
** checks out, these routines return 0.
*/
SQLITE_PRIVATE int sqlite3FixSrcList(
DbFixer *pFix, /* Context of the fixation */
SrcList *pList /* The Source list to check and modify */
){
int i;
struct SrcList_item *pItem;
sqlite3 *db = pFix->pParse->db;
int iDb = sqlite3FindDbName(db, pFix->zDb);
if( NEVER(pList==0) ) return 0;
for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
if( pFix->bTemp==0 ){
if( pItem->zDatabase && iDb!=sqlite3FindDbName(db, pItem->zDatabase) ){
sqlite3ErrorMsg(pFix->pParse,
"%s %T cannot reference objects in database %s",
pFix->zType, pFix->pName, pItem->zDatabase);
return 1;
}
sqlite3DbFree(db, pItem->zDatabase);
pItem->zDatabase = 0;
pItem->pSchema = pFix->pSchema;
pItem->fg.fromDDL = 1;
}
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;
if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1;
#endif
if( pItem->fg.isTabFunc && sqlite3FixExprList(pFix, pItem->u1.pFuncArg) ){
return 1;
}
}
return 0;
}
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
SQLITE_PRIVATE int sqlite3FixSelect(
DbFixer *pFix, /* Context of the fixation */
Select *pSelect /* The SELECT statement to be fixed to one database */
){
while( pSelect ){
if( sqlite3FixExprList(pFix, pSelect->pEList) ){
return 1;
}
if( sqlite3FixSrcList(pFix, pSelect->pSrc) ){
return 1;
}
if( sqlite3FixExpr(pFix, pSelect->pWhere) ){
return 1;
}
if( sqlite3FixExprList(pFix, pSelect->pGroupBy) ){
return 1;
}
if( sqlite3FixExpr(pFix, pSelect->pHaving) ){
return 1;
}
if( sqlite3FixExprList(pFix, pSelect->pOrderBy) ){
return 1;
}
if( sqlite3FixExpr(pFix, pSelect->pLimit) ){
return 1;
}
if( pSelect->pWith ){
int i;
for(i=0; i<pSelect->pWith->nCte; i++){
if( sqlite3FixSelect(pFix, pSelect->pWith->a[i].pSelect) ){
return 1;
}
}
}
pSelect = pSelect->pPrior;
}
return 0;
}
SQLITE_PRIVATE int sqlite3FixExpr(
DbFixer *pFix, /* Context of the fixation */
Expr *pExpr /* The expression to be fixed to one database */
){
while( pExpr ){
if( !pFix->bTemp ) ExprSetProperty(pExpr, EP_FromDDL);
if( pExpr->op==TK_VARIABLE ){
if( pFix->pParse->db->init.busy ){
pExpr->op = TK_NULL;
}else{
sqlite3ErrorMsg(pFix->pParse, "%s cannot use variables", pFix->zType);
return 1;
}
}
if( ExprHasProperty(pExpr, EP_TokenOnly|EP_Leaf) ) break;
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
if( sqlite3FixSelect(pFix, pExpr->x.pSelect) ) return 1;
}else{
if( sqlite3FixExprList(pFix, pExpr->x.pList) ) return 1;
}
if( sqlite3FixExpr(pFix, pExpr->pRight) ){
return 1;
}
pExpr = pExpr->pLeft;
}
return 0;
}
SQLITE_PRIVATE int sqlite3FixExprList(
DbFixer *pFix, /* Context of the fixation */
ExprList *pList /* The expression to be fixed to one database */
){
int i;
struct ExprList_item *pItem;
if( pList==0 ) return 0;
for(i=0, pItem=pList->a; i<pList->nExpr; i++, pItem++){
if( sqlite3FixExpr(pFix, pItem->pExpr) ){
return 1;
}
}
return 0;
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
SQLITE_PRIVATE int sqlite3FixTriggerStep(
DbFixer *pFix, /* Context of the fixation */
TriggerStep *pStep /* The trigger step be fixed to one database */
){
while( pStep ){
if( sqlite3FixSelect(pFix, pStep->pSelect) ){
return 1;
}
if( sqlite3FixExpr(pFix, pStep->pWhere) ){
return 1;
}
if( sqlite3FixExprList(pFix, pStep->pExprList) ){
return 1;
}
if( pStep->pFrom && sqlite3FixSrcList(pFix, pStep->pFrom) ){
return 1;
}
#ifndef SQLITE_OMIT_UPSERT
if( pStep->pUpsert ){
Upsert *pUp = pStep->pUpsert;
if( sqlite3FixExprList(pFix, pUp->pUpsertTarget)
|| sqlite3FixExpr(pFix, pUp->pUpsertTargetWhere)
|| sqlite3FixExprList(pFix, pUp->pUpsertSet)
|| sqlite3FixExpr(pFix, pUp->pUpsertWhere)
){
return 1;
}
}
#endif
pStep = pStep->pNext;
}
return 0;
}
#endif
/************** End of attach.c **********************************************/
/************** Begin file auth.c ********************************************/
/*
** 2003 January 11
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the sqlite3_set_authorizer()
** API. This facility is an optional feature of the library. Embedded
** systems that do not need this facility may omit it by recompiling
** the library with -DSQLITE_OMIT_AUTHORIZATION=1
*/
/* #include "sqliteInt.h" */
/*
** All of the code in this file may be omitted by defining a single
** macro.
*/
#ifndef SQLITE_OMIT_AUTHORIZATION
/*
** Set or clear the access authorization function.
**
** The access authorization function is be called during the compilation
** phase to verify that the user has read and/or write access permission on
** various fields of the database. The first argument to the auth function
** is a copy of the 3rd argument to this routine. The second argument
** to the auth function is one of these constants:
**
** SQLITE_CREATE_INDEX
** SQLITE_CREATE_TABLE
** SQLITE_CREATE_TEMP_INDEX
** SQLITE_CREATE_TEMP_TABLE
** SQLITE_CREATE_TEMP_TRIGGER
** SQLITE_CREATE_TEMP_VIEW
** SQLITE_CREATE_TRIGGER
** SQLITE_CREATE_VIEW
** SQLITE_DELETE
** SQLITE_DROP_INDEX
** SQLITE_DROP_TABLE
** SQLITE_DROP_TEMP_INDEX
** SQLITE_DROP_TEMP_TABLE
** SQLITE_DROP_TEMP_TRIGGER
** SQLITE_DROP_TEMP_VIEW
** SQLITE_DROP_TRIGGER
** SQLITE_DROP_VIEW
** SQLITE_INSERT
** SQLITE_PRAGMA
** SQLITE_READ
** SQLITE_SELECT
** SQLITE_TRANSACTION
** SQLITE_UPDATE
**
** The third and fourth arguments to the auth function are the name of
** the table and the column that are being accessed. The auth function
** should return either SQLITE_OK, SQLITE_DENY, or SQLITE_IGNORE. If
** SQLITE_OK is returned, it means that access is allowed. SQLITE_DENY
** means that the SQL statement will never-run - the sqlite3_exec() call
** will return with an error. SQLITE_IGNORE means that the SQL statement
** should run but attempts to read the specified column will return NULL
** and attempts to write the column will be ignored.
**
** Setting the auth function to NULL disables this hook. The default
** setting of the auth function is NULL.
*/
SQLITE_API int SQLITE_APICALL sqlite3_set_authorizer(
sqlite3 *db,
int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
void *pArg
){
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
sqlite3_mutex_enter(db->mutex);
db->xAuth = (sqlite3_xauth)xAuth;
db->pAuthArg = pArg;
if( db->xAuth ) sqlite3ExpirePreparedStatements(db, 1);
sqlite3_mutex_leave(db->mutex);
return SQLITE_OK;
}
/*
** Write an error message into pParse->zErrMsg that explains that the
** user-supplied authorization function returned an illegal value.
*/
static void sqliteAuthBadReturnCode(Parse *pParse){
sqlite3ErrorMsg(pParse, "authorizer malfunction");
pParse->rc = SQLITE_ERROR;
}
/*
** Invoke the authorization callback for permission to read column zCol from
** table zTab in database zDb. This function assumes that an authorization
** callback has been registered (i.e. that sqlite3.xAuth is not NULL).
**
** If SQLITE_IGNORE is returned and pExpr is not NULL, then pExpr is changed
** to an SQL NULL expression. Otherwise, if pExpr is NULL, then SQLITE_IGNORE
** is treated as SQLITE_DENY. In this case an error is left in pParse.
*/
SQLITE_PRIVATE int sqlite3AuthReadCol(
Parse *pParse, /* The parser context */
const char *zTab, /* Table name */
const char *zCol, /* Column name */
int iDb /* Index of containing database. */
){
sqlite3 *db = pParse->db; /* Database handle */
char *zDb = db->aDb[iDb].zDbSName; /* Schema name of attached database */
int rc; /* Auth callback return code */
if( db->init.busy ) return SQLITE_OK;
rc = db->xAuth(db->pAuthArg, SQLITE_READ, zTab,zCol,zDb,pParse->zAuthContext
#ifdef SQLITE_USER_AUTHENTICATION
,db->auth.zAuthUser
#endif
);
if( rc==SQLITE_DENY ){
char *z = sqlite3_mprintf("%s.%s", zTab, zCol);
if( db->nDb>2 || iDb!=0 ) z = sqlite3_mprintf("%s.%z", zDb, z);
sqlite3ErrorMsg(pParse, "access to %z is prohibited", z);
pParse->rc = SQLITE_AUTH;
}else if( rc!=SQLITE_IGNORE && rc!=SQLITE_OK ){
sqliteAuthBadReturnCode(pParse);
}
return rc;
}
/*
** The pExpr should be a TK_COLUMN expression. The table referred to
** is in pTabList or else it is the NEW or OLD table of a trigger.
** Check to see if it is OK to read this particular column.
**
** If the auth function returns SQLITE_IGNORE, change the TK_COLUMN
** instruction into a TK_NULL. If the auth function returns SQLITE_DENY,
** then generate an error.
*/
SQLITE_PRIVATE void sqlite3AuthRead(
Parse *pParse, /* The parser context */
Expr *pExpr, /* The expression to check authorization on */
Schema *pSchema, /* The schema of the expression */
SrcList *pTabList /* All table that pExpr might refer to */
){
sqlite3 *db = pParse->db;
Table *pTab = 0; /* The table being read */
const char *zCol; /* Name of the column of the table */
int iSrc; /* Index in pTabList->a[] of table being read */
int iDb; /* The index of the database the expression refers to */
int iCol; /* Index of column in table */
assert( pExpr->op==TK_COLUMN || pExpr->op==TK_TRIGGER );
assert( !IN_RENAME_OBJECT || db->xAuth==0 );
if( db->xAuth==0 ) return;
iDb = sqlite3SchemaToIndex(pParse->db, pSchema);
if( iDb<0 ){
/* An attempt to read a column out of a subquery or other
** temporary table. */
return;
}
if( pExpr->op==TK_TRIGGER ){
pTab = pParse->pTriggerTab;
}else{
assert( pTabList );
for(iSrc=0; ALWAYS(iSrc<pTabList->nSrc); iSrc++){
if( pExpr->iTable==pTabList->a[iSrc].iCursor ){
pTab = pTabList->a[iSrc].pTab;
break;
}
}
}
iCol = pExpr->iColumn;
if( NEVER(pTab==0) ) return;
if( iCol>=0 ){
assert( iCol<pTab->nCol );
zCol = pTab->aCol[iCol].zName;
}else if( pTab->iPKey>=0 ){
assert( pTab->iPKey<pTab->nCol );
zCol = pTab->aCol[pTab->iPKey].zName;
}else{
zCol = "ROWID";
}
assert( iDb>=0 && iDb<db->nDb );
if( SQLITE_IGNORE==sqlite3AuthReadCol(pParse, pTab->zName, zCol, iDb) ){
pExpr->op = TK_NULL;
}
}
/*
** Do an authorization check using the code and arguments given. Return
** either SQLITE_OK (zero) or SQLITE_IGNORE or SQLITE_DENY. If SQLITE_DENY
** is returned, then the error count and error message in pParse are
** modified appropriately.
*/
SQLITE_PRIVATE int sqlite3AuthCheck(
Parse *pParse,
int code,
const char *zArg1,
const char *zArg2,
const char *zArg3
){
sqlite3 *db = pParse->db;
int rc;
/* Don't do any authorization checks if the database is initialising
** or if the parser is being invoked from within sqlite3_declare_vtab.
*/
assert( !IN_RENAME_OBJECT || db->xAuth==0 );
if( db->init.busy || IN_SPECIAL_PARSE ){
return SQLITE_OK;
}
if( db->xAuth==0 ){
return SQLITE_OK;
}
/* EVIDENCE-OF: R-43249-19882 The third through sixth parameters to the
** callback are either NULL pointers or zero-terminated strings that
** contain additional details about the action to be authorized.
**
** The following testcase() macros show that any of the 3rd through 6th
** parameters can be either NULL or a string. */
testcase( zArg1==0 );
testcase( zArg2==0 );
testcase( zArg3==0 );
testcase( pParse->zAuthContext==0 );
rc = db->xAuth(db->pAuthArg, code, zArg1, zArg2, zArg3, pParse->zAuthContext
#ifdef SQLITE_USER_AUTHENTICATION
,db->auth.zAuthUser
#endif
);
if( rc==SQLITE_DENY ){
sqlite3ErrorMsg(pParse, "not authorized");
pParse->rc = SQLITE_AUTH;
}else if( rc!=SQLITE_OK && rc!=SQLITE_IGNORE ){
rc = SQLITE_DENY;
sqliteAuthBadReturnCode(pParse);
}
return rc;
}
/*
** Push an authorization context. After this routine is called, the
** zArg3 argument to authorization callbacks will be zContext until
** popped. Or if pParse==0, this routine is a no-op.
*/
SQLITE_PRIVATE void sqlite3AuthContextPush(
Parse *pParse,
AuthContext *pContext,
const char *zContext
){
assert( pParse );
pContext->pParse = pParse;
pContext->zAuthContext = pParse->zAuthContext;
pParse->zAuthContext = zContext;
}
/*
** Pop an authorization context that was previously pushed
** by sqlite3AuthContextPush
*/
SQLITE_PRIVATE void sqlite3AuthContextPop(AuthContext *pContext){
if( pContext->pParse ){
pContext->pParse->zAuthContext = pContext->zAuthContext;
pContext->pParse = 0;
}
}
#endif /* SQLITE_OMIT_AUTHORIZATION */
/************** End of auth.c ************************************************/
/************** Begin file build.c *******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the SQLite parser
** when syntax rules are reduced. The routines in this file handle the
** following kinds of SQL syntax:
**
** CREATE TABLE
** DROP TABLE
** CREATE INDEX
** DROP INDEX
** creating ID lists
** BEGIN TRANSACTION
** COMMIT
** ROLLBACK
*/
/* #include "sqliteInt.h" */
#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** The TableLock structure is only used by the sqlite3TableLock() and
** codeTableLocks() functions.
*/
struct TableLock {
int iDb; /* The database containing the table to be locked */
Pgno iTab; /* The root page of the table to be locked */
u8 isWriteLock; /* True for write lock. False for a read lock */
const char *zLockName; /* Name of the table */
};
/*
** Record the fact that we want to lock a table at run-time.
**
** The table to be locked has root page iTab and is found in database iDb.
** A read or a write lock can be taken depending on isWritelock.
**
** This routine just records the fact that the lock is desired. The
** code to make the lock occur is generated by a later call to
** codeTableLocks() which occurs during sqlite3FinishCoding().
*/
SQLITE_PRIVATE void sqlite3TableLock(
Parse *pParse, /* Parsing context */
int iDb, /* Index of the database containing the table to lock */
Pgno iTab, /* Root page number of the table to be locked */
u8 isWriteLock, /* True for a write lock */
const char *zName /* Name of the table to be locked */
){
Parse *pToplevel;
int i;
int nBytes;
TableLock *p;
assert( iDb>=0 );
if( iDb==1 ) return;
if( !sqlite3BtreeSharable(pParse->db->aDb[iDb].pBt) ) return;
pToplevel = sqlite3ParseToplevel(pParse);
for(i=0; i<pToplevel->nTableLock; i++){
p = &pToplevel->aTableLock[i];
if( p->iDb==iDb && p->iTab==iTab ){
p->isWriteLock = (p->isWriteLock || isWriteLock);
return;
}
}
nBytes = sizeof(TableLock) * (pToplevel->nTableLock+1);
pToplevel->aTableLock =
sqlite3DbReallocOrFree(pToplevel->db, pToplevel->aTableLock, nBytes);
if( pToplevel->aTableLock ){
p = &pToplevel->aTableLock[pToplevel->nTableLock++];
p->iDb = iDb;
p->iTab = iTab;
p->isWriteLock = isWriteLock;
p->zLockName = zName;
}else{
pToplevel->nTableLock = 0;
sqlite3OomFault(pToplevel->db);
}
}
/*
** Code an OP_TableLock instruction for each table locked by the
** statement (configured by calls to sqlite3TableLock()).
*/
static void codeTableLocks(Parse *pParse){
int i;
Vdbe *pVdbe = pParse->pVdbe;
assert( pVdbe!=0 );
for(i=0; i<pParse->nTableLock; i++){
TableLock *p = &pParse->aTableLock[i];
int p1 = p->iDb;
sqlite3VdbeAddOp4(pVdbe, OP_TableLock, p1, p->iTab, p->isWriteLock,
p->zLockName, P4_STATIC);
}
}
#else
#define codeTableLocks(x)
#endif
/*
** Return TRUE if the given yDbMask object is empty - if it contains no
** 1 bits. This routine is used by the DbMaskAllZero() and DbMaskNotZero()
** macros when SQLITE_MAX_ATTACHED is greater than 30.
*/
#if SQLITE_MAX_ATTACHED>30
SQLITE_PRIVATE int sqlite3DbMaskAllZero(yDbMask m){
int i;
for(i=0; i<sizeof(yDbMask); i++) if( m[i] ) return 0;
return 1;
}
#endif
/*
** This routine is called after a single SQL statement has been
** parsed and a VDBE program to execute that statement has been
** prepared. This routine puts the finishing touches on the
** VDBE program and resets the pParse structure for the next
** parse.
**
** Note that if an error occurred, it might be the case that
** no VDBE code was generated.
*/
SQLITE_PRIVATE void sqlite3FinishCoding(Parse *pParse){
sqlite3 *db;
Vdbe *v;
assert( pParse->pToplevel==0 );
db = pParse->db;
if( pParse->nested ) return;
if( db->mallocFailed || pParse->nErr ){
if( pParse->rc==SQLITE_OK ) pParse->rc = SQLITE_ERROR;
return;
}
/* Begin by generating some termination code at the end of the
** vdbe program
*/
v = sqlite3GetVdbe(pParse);
assert( !pParse->isMultiWrite
|| sqlite3VdbeAssertMayAbort(v, pParse->mayAbort));
if( v ){
sqlite3VdbeAddOp0(v, OP_Halt);
#if SQLITE_USER_AUTHENTICATION
if( pParse->nTableLock>0 && db->init.busy==0 ){
sqlite3UserAuthInit(db);
if( db->auth.authLevel<UAUTH_User ){
sqlite3ErrorMsg(pParse, "user not authenticated");
pParse->rc = SQLITE_AUTH_USER;
return;
}
}
#endif
/* The cookie mask contains one bit for each database file open.
** (Bit 0 is for main, bit 1 is for temp, and so forth.) Bits are
** set for each database that is used. Generate code to start a
** transaction on each used database and to verify the schema cookie
** on each used database.
*/
if( db->mallocFailed==0
&& (DbMaskNonZero(pParse->cookieMask) || pParse->pConstExpr)
){
int iDb, i;
assert( sqlite3VdbeGetOp(v, 0)->opcode==OP_Init );
sqlite3VdbeJumpHere(v, 0);
for(iDb=0; iDb<db->nDb; iDb++){
Schema *pSchema;
if( DbMaskTest(pParse->cookieMask, iDb)==0 ) continue;
sqlite3VdbeUsesBtree(v, iDb);
pSchema = db->aDb[iDb].pSchema;
sqlite3VdbeAddOp4Int(v,
OP_Transaction, /* Opcode */
iDb, /* P1 */
DbMaskTest(pParse->writeMask,iDb), /* P2 */
pSchema->schema_cookie, /* P3 */
pSchema->iGeneration /* P4 */
);
if( db->init.busy==0 ) sqlite3VdbeChangeP5(v, 1);
VdbeComment((v,
"usesStmtJournal=%d", pParse->mayAbort && pParse->isMultiWrite));
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
for(i=0; i<pParse->nVtabLock; i++){
char *vtab = (char *)sqlite3GetVTable(db, pParse->apVtabLock[i]);
sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
}
pParse->nVtabLock = 0;
#endif
/* Once all the cookies have been verified and transactions opened,
** obtain the required table-locks. This is a no-op unless the
** shared-cache feature is enabled.
*/
codeTableLocks(pParse);
/* Initialize any AUTOINCREMENT data structures required.
*/
sqlite3AutoincrementBegin(pParse);
/* Code constant expressions that where factored out of inner loops.
**
** The pConstExpr list might also contain expressions that we simply
** want to keep around until the Parse object is deleted. Such
** expressions have iConstExprReg==0. Do not generate code for
** those expressions, of course.
*/
if( pParse->pConstExpr ){
ExprList *pEL = pParse->pConstExpr;
pParse->okConstFactor = 0;
for(i=0; i<pEL->nExpr; i++){
int iReg = pEL->a[i].u.iConstExprReg;
if( iReg>0 ){
sqlite3ExprCode(pParse, pEL->a[i].pExpr, iReg);
}
}
}
/* Finally, jump back to the beginning of the executable code. */
sqlite3VdbeGoto(v, 1);
}
}
/* Get the VDBE program ready for execution
*/
if( v && pParse->nErr==0 && !db->mallocFailed ){
/* A minimum of one cursor is required if autoincrement is used
* See ticket [a696379c1f08866] */
assert( pParse->pAinc==0 || pParse->nTab>0 );
sqlite3VdbeMakeReady(v, pParse);
pParse->rc = SQLITE_DONE;
}else{
pParse->rc = SQLITE_ERROR;
}
}
/*
** Run the parser and code generator recursively in order to generate
** code for the SQL statement given onto the end of the pParse context
** currently under construction. When the parser is run recursively
** this way, the final OP_Halt is not appended and other initialization
** and finalization steps are omitted because those are handling by the
** outermost parser.
**
** Not everything is nestable. This facility is designed to permit
** INSERT, UPDATE, and DELETE operations against the schema table. Use
** care if you decide to try to use this routine for some other purposes.
*/
SQLITE_PRIVATE void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
va_list ap;
char *zSql;
char *zErrMsg = 0;
sqlite3 *db = pParse->db;
char saveBuf[PARSE_TAIL_SZ];
if( pParse->nErr ) return;
assert( pParse->nested<10 ); /* Nesting should only be of limited depth */
va_start(ap, zFormat);
zSql = sqlite3VMPrintf(db, zFormat, ap);
va_end(ap);
if( zSql==0 ){
/* This can result either from an OOM or because the formatted string
** exceeds SQLITE_LIMIT_LENGTH. In the latter case, we need to set
** an error */
if( !db->mallocFailed ) pParse->rc = SQLITE_TOOBIG;
pParse->nErr++;
return;
}
pParse->nested++;
memcpy(saveBuf, PARSE_TAIL(pParse), PARSE_TAIL_SZ);
memset(PARSE_TAIL(pParse), 0, PARSE_TAIL_SZ);
sqlite3RunParser(pParse, zSql, &zErrMsg);
sqlite3DbFree(db, zErrMsg);
sqlite3DbFree(db, zSql);
memcpy(PARSE_TAIL(pParse), saveBuf, PARSE_TAIL_SZ);
pParse->nested--;
}
#if SQLITE_USER_AUTHENTICATION
/*
** Return TRUE if zTable is the name of the system table that stores the
** list of users and their access credentials.
*/
SQLITE_PRIVATE int sqlite3UserAuthTable(const char *zTable){
return sqlite3_stricmp(zTable, "sqlite_user")==0;
}
#endif
/*
** Locate the in-memory structure that describes a particular database
** table given the name of that table and (optionally) the name of the
** database containing the table. Return NULL if not found.
**
** If zDatabase is 0, all databases are searched for the table and the
** first matching table is returned. (No checking for duplicate table
** names is done.) The search order is TEMP first, then MAIN, then any
** auxiliary databases added using the ATTACH command.
**
** See also sqlite3LocateTable().
*/
SQLITE_PRIVATE Table *sqlite3FindTable(sqlite3 *db, const char *zName, const char *zDatabase){
Table *p = 0;
int i;
/* All mutexes are required for schema access. Make sure we hold them. */
assert( zDatabase!=0 || sqlite3BtreeHoldsAllMutexes(db) );
#if SQLITE_USER_AUTHENTICATION
/* Only the admin user is allowed to know that the sqlite_user table
** exists */
if( db->auth.authLevel<UAUTH_Admin && sqlite3UserAuthTable(zName)!=0 ){
return 0;
}
#endif
if( zDatabase ){
for(i=0; i<db->nDb; i++){
if( sqlite3StrICmp(zDatabase, db->aDb[i].zDbSName)==0 ) break;
}
if( i>=db->nDb ){
/* No match against the official names. But always match "main"
** to schema 0 as a legacy fallback. */
if( sqlite3StrICmp(zDatabase,"main")==0 ){
i = 0;
}else{
return 0;
}
}
p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash, zName);
if( p==0 && sqlite3StrNICmp(zName, "sqlite_", 7)==0 ){
if( i==1 ){
if( sqlite3StrICmp(zName+7, &ALT_TEMP_SCHEMA_TABLE[7])==0
|| sqlite3StrICmp(zName+7, &ALT_SCHEMA_TABLE[7])==0
|| sqlite3StrICmp(zName+7, &DFLT_SCHEMA_TABLE[7])==0
){
p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash,
DFLT_TEMP_SCHEMA_TABLE);
}
}else{
if( sqlite3StrICmp(zName+7, &ALT_SCHEMA_TABLE[7])==0 ){
p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash,
DFLT_SCHEMA_TABLE);
}
}
}
}else{
/* Match against TEMP first */
p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash, zName);
if( p ) return p;
/* The main database is second */
p = sqlite3HashFind(&db->aDb[0].pSchema->tblHash, zName);
if( p ) return p;
/* Attached databases are in order of attachment */
for(i=2; i<db->nDb; i++){
assert( sqlite3SchemaMutexHeld(db, i, 0) );
p = sqlite3HashFind(&db->aDb[i].pSchema->tblHash, zName);
if( p ) break;
}
if( p==0 && sqlite3StrNICmp(zName, "sqlite_", 7)==0 ){
if( sqlite3StrICmp(zName+7, &ALT_SCHEMA_TABLE[7])==0 ){
p = sqlite3HashFind(&db->aDb[0].pSchema->tblHash, DFLT_SCHEMA_TABLE);
}else if( sqlite3StrICmp(zName+7, &ALT_TEMP_SCHEMA_TABLE[7])==0 ){
p = sqlite3HashFind(&db->aDb[1].pSchema->tblHash,
DFLT_TEMP_SCHEMA_TABLE);
}
}
}
return p;
}
/*
** Locate the in-memory structure that describes a particular database
** table given the name of that table and (optionally) the name of the
** database containing the table. Return NULL if not found. Also leave an
** error message in pParse->zErrMsg.
**
** The difference between this routine and sqlite3FindTable() is that this
** routine leaves an error message in pParse->zErrMsg where
** sqlite3FindTable() does not.
*/
SQLITE_PRIVATE Table *sqlite3LocateTable(
Parse *pParse, /* context in which to report errors */
u32 flags, /* LOCATE_VIEW or LOCATE_NOERR */
const char *zName, /* Name of the table we are looking for */
const char *zDbase /* Name of the database. Might be NULL */
){
Table *p;
sqlite3 *db = pParse->db;
/* Read the database schema. If an error occurs, leave an error message
** and code in pParse and return NULL. */
if( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0
&& SQLITE_OK!=sqlite3ReadSchema(pParse)
){
return 0;
}
p = sqlite3FindTable(db, zName, zDbase);
if( p==0 ){
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* If zName is the not the name of a table in the schema created using
** CREATE, then check to see if it is the name of an virtual table that
** can be an eponymous virtual table. */
if( pParse->disableVtab==0 ){
Module *pMod = (Module*)sqlite3HashFind(&db->aModule, zName);
if( pMod==0 && sqlite3_strnicmp(zName, "pragma_", 7)==0 ){
pMod = sqlite3PragmaVtabRegister(db, zName);
}
if( pMod && sqlite3VtabEponymousTableInit(pParse, pMod) ){
return pMod->pEpoTab;
}
}
#endif
if( flags & LOCATE_NOERR ) return 0;
pParse->checkSchema = 1;
}else if( IsVirtual(p) && pParse->disableVtab ){
p = 0;
}
if( p==0 ){
const char *zMsg = flags & LOCATE_VIEW ? "no such view" : "no such table";
if( zDbase ){
sqlite3ErrorMsg(pParse, "%s: %s.%s", zMsg, zDbase, zName);
}else{
sqlite3ErrorMsg(pParse, "%s: %s", zMsg, zName);
}
}
return p;
}
/*
** Locate the table identified by *p.
**
** This is a wrapper around sqlite3LocateTable(). The difference between
** sqlite3LocateTable() and this function is that this function restricts
** the search to schema (p->pSchema) if it is not NULL. p->pSchema may be
** non-NULL if it is part of a view or trigger program definition. See
** sqlite3FixSrcList() for details.
*/
SQLITE_PRIVATE Table *sqlite3LocateTableItem(
Parse *pParse,
u32 flags,
struct SrcList_item *p
){
const char *zDb;
assert( p->pSchema==0 || p->zDatabase==0 );
if( p->pSchema ){
int iDb = sqlite3SchemaToIndex(pParse->db, p->pSchema);
zDb = pParse->db->aDb[iDb].zDbSName;
}else{
zDb = p->zDatabase;
}
return sqlite3LocateTable(pParse, flags, p->zName, zDb);
}
/*
** Locate the in-memory structure that describes
** a particular index given the name of that index
** and the name of the database that contains the index.
** Return NULL if not found.
**
** If zDatabase is 0, all databases are searched for the
** table and the first matching index is returned. (No checking
** for duplicate index names is done.) The search order is
** TEMP first, then MAIN, then any auxiliary databases added
** using the ATTACH command.
*/
SQLITE_PRIVATE Index *sqlite3FindIndex(sqlite3 *db, const char *zName, const char *zDb){
Index *p = 0;
int i;
/* All mutexes are required for schema access. Make sure we hold them. */
assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
for(i=OMIT_TEMPDB; i<db->nDb; i++){
int j = (i<2) ? i^1 : i; /* Search TEMP before MAIN */
Schema *pSchema = db->aDb[j].pSchema;
assert( pSchema );
if( zDb && sqlite3DbIsNamed(db, j, zDb)==0 ) continue;
assert( sqlite3SchemaMutexHeld(db, j, 0) );
p = sqlite3HashFind(&pSchema->idxHash, zName);
if( p ) break;
}
return p;
}
/*
** Reclaim the memory used by an index
*/
SQLITE_PRIVATE void sqlite3FreeIndex(sqlite3 *db, Index *p){
#ifndef SQLITE_OMIT_ANALYZE
sqlite3DeleteIndexSamples(db, p);
#endif
sqlite3ExprDelete(db, p->pPartIdxWhere);
sqlite3ExprListDelete(db, p->aColExpr);
sqlite3DbFree(db, p->zColAff);
if( p->isResized ) sqlite3DbFree(db, (void *)p->azColl);
#ifdef SQLITE_ENABLE_STAT4
sqlite3_free(p->aiRowEst);
#endif
sqlite3DbFree(db, p);
}
/*
** For the index called zIdxName which is found in the database iDb,
** unlike that index from its Table then remove the index from
** the index hash table and free all memory structures associated
** with the index.
*/
SQLITE_PRIVATE void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char *zIdxName){
Index *pIndex;
Hash *pHash;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
pHash = &db->aDb[iDb].pSchema->idxHash;
pIndex = sqlite3HashInsert(pHash, zIdxName, 0);
if( ALWAYS(pIndex) ){
if( pIndex->pTable->pIndex==pIndex ){
pIndex->pTable->pIndex = pIndex->pNext;
}else{
Index *p;
/* Justification of ALWAYS(); The index must be on the list of
** indices. */
p = pIndex->pTable->pIndex;
while( ALWAYS(p) && p->pNext!=pIndex ){ p = p->pNext; }
if( ALWAYS(p && p->pNext==pIndex) ){
p->pNext = pIndex->pNext;
}
}
sqlite3FreeIndex(db, pIndex);
}
db->mDbFlags |= DBFLAG_SchemaChange;
}
/*
** Look through the list of open database files in db->aDb[] and if
** any have been closed, remove them from the list. Reallocate the
** db->aDb[] structure to a smaller size, if possible.
**
** Entry 0 (the "main" database) and entry 1 (the "temp" database)
** are never candidates for being collapsed.
*/
SQLITE_PRIVATE void sqlite3CollapseDatabaseArray(sqlite3 *db){
int i, j;
for(i=j=2; i<db->nDb; i++){
struct Db *pDb = &db->aDb[i];
if( pDb->pBt==0 ){
sqlite3DbFree(db, pDb->zDbSName);
pDb->zDbSName = 0;
continue;
}
if( j<i ){
db->aDb[j] = db->aDb[i];
}
j++;
}
db->nDb = j;
if( db->nDb<=2 && db->aDb!=db->aDbStatic ){
memcpy(db->aDbStatic, db->aDb, 2*sizeof(db->aDb[0]));
sqlite3DbFree(db, db->aDb);
db->aDb = db->aDbStatic;
}
}
/*
** Reset the schema for the database at index iDb. Also reset the
** TEMP schema. The reset is deferred if db->nSchemaLock is not zero.
** Deferred resets may be run by calling with iDb<0.
*/
SQLITE_PRIVATE void sqlite3ResetOneSchema(sqlite3 *db, int iDb){
int i;
assert( iDb<db->nDb );
if( iDb>=0 ){
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
DbSetProperty(db, iDb, DB_ResetWanted);
DbSetProperty(db, 1, DB_ResetWanted);
db->mDbFlags &= ~DBFLAG_SchemaKnownOk;
}
if( db->nSchemaLock==0 ){
for(i=0; i<db->nDb; i++){
if( DbHasProperty(db, i, DB_ResetWanted) ){
sqlite3SchemaClear(db->aDb[i].pSchema);
}
}
}
}
/*
** Erase all schema information from all attached databases (including
** "main" and "temp") for a single database connection.
*/
SQLITE_PRIVATE void sqlite3ResetAllSchemasOfConnection(sqlite3 *db){
int i;
sqlite3BtreeEnterAll(db);
for(i=0; i<db->nDb; i++){
Db *pDb = &db->aDb[i];
if( pDb->pSchema ){
if( db->nSchemaLock==0 ){
sqlite3SchemaClear(pDb->pSchema);
}else{
DbSetProperty(db, i, DB_ResetWanted);
}
}
}
db->mDbFlags &= ~(DBFLAG_SchemaChange|DBFLAG_SchemaKnownOk);
sqlite3VtabUnlockList(db);
sqlite3BtreeLeaveAll(db);
if( db->nSchemaLock==0 ){
sqlite3CollapseDatabaseArray(db);
}
}
/*
** This routine is called when a commit occurs.
*/
SQLITE_PRIVATE void sqlite3CommitInternalChanges(sqlite3 *db){
db->mDbFlags &= ~DBFLAG_SchemaChange;
}
/*
** Delete memory allocated for the column names of a table or view (the
** Table.aCol[] array).
*/
SQLITE_PRIVATE void sqlite3DeleteColumnNames(sqlite3 *db, Table *pTable){
int i;
Column *pCol;
assert( pTable!=0 );
if( (pCol = pTable->aCol)!=0 ){
for(i=0; i<pTable->nCol; i++, pCol++){
assert( pCol->zName==0 || pCol->hName==sqlite3StrIHash(pCol->zName) );
sqlite3DbFree(db, pCol->zName);
sqlite3ExprDelete(db, pCol->pDflt);
sqlite3DbFree(db, pCol->zColl);
}
sqlite3DbFree(db, pTable->aCol);
}
}
/*
** Remove the memory data structures associated with the given
** Table. No changes are made to disk by this routine.
**
** This routine just deletes the data structure. It does not unlink
** the table data structure from the hash table. But it does destroy
** memory structures of the indices and foreign keys associated with
** the table.
**
** The db parameter is optional. It is needed if the Table object
** contains lookaside memory. (Table objects in the schema do not use
** lookaside memory, but some ephemeral Table objects do.) Or the
** db parameter can be used with db->pnBytesFreed to measure the memory
** used by the Table object.
*/
static void SQLITE_NOINLINE deleteTable(sqlite3 *db, Table *pTable){
Index *pIndex, *pNext;
#ifdef SQLITE_DEBUG
/* Record the number of outstanding lookaside allocations in schema Tables
** prior to doing any free() operations. Since schema Tables do not use
** lookaside, this number should not change.
**
** If malloc has already failed, it may be that it failed while allocating
** a Table object that was going to be marked ephemeral. So do not check
** that no lookaside memory is used in this case either. */
int nLookaside = 0;
if( db && !db->mallocFailed && (pTable->tabFlags & TF_Ephemeral)==0 ){
nLookaside = sqlite3LookasideUsed(db, 0);
}
#endif
/* Delete all indices associated with this table. */
for(pIndex = pTable->pIndex; pIndex; pIndex=pNext){
pNext = pIndex->pNext;
assert( pIndex->pSchema==pTable->pSchema
|| (IsVirtual(pTable) && pIndex->idxType!=SQLITE_IDXTYPE_APPDEF) );
if( (db==0 || db->pnBytesFreed==0) && !IsVirtual(pTable) ){
char *zName = pIndex->zName;
TESTONLY ( Index *pOld = ) sqlite3HashInsert(
&pIndex->pSchema->idxHash, zName, 0
);
assert( db==0 || sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
assert( pOld==pIndex || pOld==0 );
}
sqlite3FreeIndex(db, pIndex);
}
/* Delete any foreign keys attached to this table. */
sqlite3FkDelete(db, pTable);
/* Delete the Table structure itself.
*/
sqlite3DeleteColumnNames(db, pTable);
sqlite3DbFree(db, pTable->zName);
sqlite3DbFree(db, pTable->zColAff);
sqlite3SelectDelete(db, pTable->pSelect);
sqlite3ExprListDelete(db, pTable->pCheck);
#ifndef SQLITE_OMIT_VIRTUALTABLE
sqlite3VtabClear(db, pTable);
#endif
sqlite3DbFree(db, pTable);
/* Verify that no lookaside memory was used by schema tables */
assert( nLookaside==0 || nLookaside==sqlite3LookasideUsed(db,0) );
}
SQLITE_PRIVATE void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
/* Do not delete the table until the reference count reaches zero. */
if( !pTable ) return;
if( ((!db || db->pnBytesFreed==0) && (--pTable->nTabRef)>0) ) return;
deleteTable(db, pTable);
}
/*
** Unlink the given table from the hash tables and the delete the
** table structure with all its indices and foreign keys.
*/
SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){
Table *p;
Db *pDb;
assert( db!=0 );
assert( iDb>=0 && iDb<db->nDb );
assert( zTabName );
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
testcase( zTabName[0]==0 ); /* Zero-length table names are allowed */
pDb = &db->aDb[iDb];
p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName, 0);
sqlite3DeleteTable(db, p);
db->mDbFlags |= DBFLAG_SchemaChange;
}
/*
** Given a token, return a string that consists of the text of that
** token. Space to hold the returned string
** is obtained from sqliteMalloc() and must be freed by the calling
** function.
**
** Any quotation marks (ex: "name", 'name', [name], or `name`) that
** surround the body of the token are removed.
**
** Tokens are often just pointers into the original SQL text and so
** are not \000 terminated and are not persistent. The returned string
** is \000 terminated and is persistent.
*/
SQLITE_PRIVATE char *sqlite3NameFromToken(sqlite3 *db, Token *pName){
char *zName;
if( pName ){
zName = sqlite3DbStrNDup(db, (char*)pName->z, pName->n);
sqlite3Dequote(zName);
}else{
zName = 0;
}
return zName;
}
/*
** Open the sqlite_schema table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
SQLITE_PRIVATE void sqlite3OpenSchemaTable(Parse *p, int iDb){
Vdbe *v = sqlite3GetVdbe(p);
sqlite3TableLock(p, iDb, SCHEMA_ROOT, 1, DFLT_SCHEMA_TABLE);
sqlite3VdbeAddOp4Int(v, OP_OpenWrite, 0, SCHEMA_ROOT, iDb, 5);
if( p->nTab==0 ){
p->nTab = 1;
}
}
/*
** Parameter zName points to a nul-terminated buffer containing the name
** of a database ("main", "temp" or the name of an attached db). This
** function returns the index of the named database in db->aDb[], or
** -1 if the named db cannot be found.
*/
SQLITE_PRIVATE int sqlite3FindDbName(sqlite3 *db, const char *zName){
int i = -1; /* Database number */
if( zName ){
Db *pDb;
for(i=(db->nDb-1), pDb=&db->aDb[i]; i>=0; i--, pDb--){
if( 0==sqlite3_stricmp(pDb->zDbSName, zName) ) break;
/* "main" is always an acceptable alias for the primary database
** even if it has been renamed using SQLITE_DBCONFIG_MAINDBNAME. */
if( i==0 && 0==sqlite3_stricmp("main", zName) ) break;
}
}
return i;
}
/*
** The token *pName contains the name of a database (either "main" or
** "temp" or the name of an attached db). This routine returns the
** index of the named database in db->aDb[], or -1 if the named db
** does not exist.
*/
SQLITE_PRIVATE int sqlite3FindDb(sqlite3 *db, Token *pName){
int i; /* Database number */
char *zName; /* Name we are searching for */
zName = sqlite3NameFromToken(db, pName);
i = sqlite3FindDbName(db, zName);
sqlite3DbFree(db, zName);
return i;
}
/* The table or view or trigger name is passed to this routine via tokens
** pName1 and pName2. If the table name was fully qualified, for example:
**
** CREATE TABLE xxx.yyy (...);
**
** Then pName1 is set to "xxx" and pName2 "yyy". On the other hand if
** the table name is not fully qualified, i.e.:
**
** CREATE TABLE yyy(...);
**
** Then pName1 is set to "yyy" and pName2 is "".
**
** This routine sets the *ppUnqual pointer to point at the token (pName1 or
** pName2) that stores the unqualified table name. The index of the
** database "xxx" is returned.
*/
SQLITE_PRIVATE int sqlite3TwoPartName(
Parse *pParse, /* Parsing and code generating context */
Token *pName1, /* The "xxx" in the name "xxx.yyy" or "xxx" */
Token *pName2, /* The "yyy" in the name "xxx.yyy" */
Token **pUnqual /* Write the unqualified object name here */
){
int iDb; /* Database holding the object */
sqlite3 *db = pParse->db;
assert( pName2!=0 );
if( pName2->n>0 ){
if( db->init.busy ) {
sqlite3ErrorMsg(pParse, "corrupt database");
return -1;
}
*pUnqual = pName2;
iDb = sqlite3FindDb(db, pName1);
if( iDb<0 ){
sqlite3ErrorMsg(pParse, "unknown database %T", pName1);
return -1;
}
}else{
assert( db->init.iDb==0 || db->init.busy || IN_RENAME_OBJECT
|| (db->mDbFlags & DBFLAG_Vacuum)!=0);
iDb = db->init.iDb;
*pUnqual = pName1;
}
return iDb;
}
/*
** True if PRAGMA writable_schema is ON
*/
SQLITE_PRIVATE int sqlite3WritableSchema(sqlite3 *db){
testcase( (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==0 );
testcase( (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==
SQLITE_WriteSchema );
testcase( (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==
SQLITE_Defensive );
testcase( (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==
(SQLITE_WriteSchema|SQLITE_Defensive) );
return (db->flags&(SQLITE_WriteSchema|SQLITE_Defensive))==SQLITE_WriteSchema;
}
/*
** This routine is used to check if the UTF-8 string zName is a legal
** unqualified name for a new schema object (table, index, view or
** trigger). All names are legal except those that begin with the string
** "sqlite_" (in upper, lower or mixed case). This portion of the namespace
** is reserved for internal use.
**
** When parsing the sqlite_schema table, this routine also checks to
** make sure the "type", "name", and "tbl_name" columns are consistent
** with the SQL.
*/
SQLITE_PRIVATE int sqlite3CheckObjectName(
Parse *pParse, /* Parsing context */
const char *zName, /* Name of the object to check */
const char *zType, /* Type of this object */
const char *zTblName /* Parent table name for triggers and indexes */
){
sqlite3 *db = pParse->db;
if( sqlite3WritableSchema(db)
|| db->init.imposterTable
|| !sqlite3Config.bExtraSchemaChecks
){
/* Skip these error checks for writable_schema=ON */
return SQLITE_OK;
}
if( db->init.busy ){
if( sqlite3_stricmp(zType, db->init.azInit[0])
|| sqlite3_stricmp(zName, db->init.azInit[1])
|| sqlite3_stricmp(zTblName, db->init.azInit[2])
){
sqlite3ErrorMsg(pParse, ""); /* corruptSchema() will supply the error */
return SQLITE_ERROR;
}
}else{
if( (pParse->nested==0 && 0==sqlite3StrNICmp(zName, "sqlite_", 7))
|| (sqlite3ReadOnlyShadowTables(db) && sqlite3ShadowTableName(db, zName))
){
sqlite3ErrorMsg(pParse, "object name reserved for internal use: %s",
zName);
return SQLITE_ERROR;
}
}
return SQLITE_OK;
}
/*
** Return the PRIMARY KEY index of a table
*/
SQLITE_PRIVATE Index *sqlite3PrimaryKeyIndex(Table *pTab){
Index *p;
for(p=pTab->pIndex; p && !IsPrimaryKeyIndex(p); p=p->pNext){}
return p;
}
/*
** Convert an table column number into a index column number. That is,
** for the column iCol in the table (as defined by the CREATE TABLE statement)
** find the (first) offset of that column in index pIdx. Or return -1
** if column iCol is not used in index pIdx.
*/
SQLITE_PRIVATE i16 sqlite3TableColumnToIndex(Index *pIdx, i16 iCol){
int i;
for(i=0; i<pIdx->nColumn; i++){
if( iCol==pIdx->aiColumn[i] ) return i;
}
return -1;
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* Convert a storage column number into a table column number.
**
** The storage column number (0,1,2,....) is the index of the value
** as it appears in the record on disk. The true column number
** is the index (0,1,2,...) of the column in the CREATE TABLE statement.
**
** The storage column number is less than the table column number if
** and only there are VIRTUAL columns to the left.
**
** If SQLITE_OMIT_GENERATED_COLUMNS, this routine is a no-op macro.
*/
SQLITE_PRIVATE i16 sqlite3StorageColumnToTable(Table *pTab, i16 iCol){
if( pTab->tabFlags & TF_HasVirtual ){
int i;
for(i=0; i<=iCol; i++){
if( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL ) iCol++;
}
}
return iCol;
}
#endif
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* Convert a table column number into a storage column number.
**
** The storage column number (0,1,2,....) is the index of the value
** as it appears in the record on disk. Or, if the input column is
** the N-th virtual column (zero-based) then the storage number is
** the number of non-virtual columns in the table plus N.
**
** The true column number is the index (0,1,2,...) of the column in
** the CREATE TABLE statement.
**
** If the input column is a VIRTUAL column, then it should not appear
** in storage. But the value sometimes is cached in registers that
** follow the range of registers used to construct storage. This
** avoids computing the same VIRTUAL column multiple times, and provides
** values for use by OP_Param opcodes in triggers. Hence, if the
** input column is a VIRTUAL table, put it after all the other columns.
**
** In the following, N means "normal column", S means STORED, and
** V means VIRTUAL. Suppose the CREATE TABLE has columns like this:
**
** CREATE TABLE ex(N,S,V,N,S,V,N,S,V);
** -- 0 1 2 3 4 5 6 7 8
**
** Then the mapping from this function is as follows:
**
** INPUTS: 0 1 2 3 4 5 6 7 8
** OUTPUTS: 0 1 6 2 3 7 4 5 8
**
** So, in other words, this routine shifts all the virtual columns to
** the end.
**
** If SQLITE_OMIT_GENERATED_COLUMNS then there are no virtual columns and
** this routine is a no-op macro. If the pTab does not have any virtual
** columns, then this routine is no-op that always return iCol. If iCol
** is negative (indicating the ROWID column) then this routine return iCol.
*/
SQLITE_PRIVATE i16 sqlite3TableColumnToStorage(Table *pTab, i16 iCol){
int i;
i16 n;
assert( iCol<pTab->nCol );
if( (pTab->tabFlags & TF_HasVirtual)==0 || iCol<0 ) return iCol;
for(i=0, n=0; i<iCol; i++){
if( (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0 ) n++;
}
if( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL ){
/* iCol is a virtual column itself */
return pTab->nNVCol + i - n;
}else{
/* iCol is a normal or stored column */
return n;
}
}
#endif
/*
** Begin constructing a new table representation in memory. This is
** the first of several action routines that get called in response
** to a CREATE TABLE statement. In particular, this routine is called
** after seeing tokens "CREATE" and "TABLE" and the table name. The isTemp
** flag is true if the table should be stored in the auxiliary database
** file instead of in the main database file. This is normally the case
** when the "TEMP" or "TEMPORARY" keyword occurs in between
** CREATE and TABLE.
**
** The new table record is initialized and put in pParse->pNewTable.
** As more of the CREATE TABLE statement is parsed, additional action
** routines will be called to add more information to this record.
** At the end of the CREATE TABLE statement, the sqlite3EndTable() routine
** is called to complete the construction of the new table record.
*/
SQLITE_PRIVATE void sqlite3StartTable(
Parse *pParse, /* Parser context */
Token *pName1, /* First part of the name of the table or view */
Token *pName2, /* Second part of the name of the table or view */
int isTemp, /* True if this is a TEMP table */
int isView, /* True if this is a VIEW */
int isVirtual, /* True if this is a VIRTUAL table */
int noErr /* Do nothing if table already exists */
){
Table *pTable;
char *zName = 0; /* The name of the new table */
sqlite3 *db = pParse->db;
Vdbe *v;
int iDb; /* Database number to create the table in */
Token *pName; /* Unqualified name of the table to create */
if( db->init.busy && db->init.newTnum==1 ){
/* Special case: Parsing the sqlite_schema or sqlite_temp_schema schema */
iDb = db->init.iDb;
zName = sqlite3DbStrDup(db, SCHEMA_TABLE(iDb));
pName = pName1;
}else{
/* The common case */
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
if( iDb<0 ) return;
if( !OMIT_TEMPDB && isTemp && pName2->n>0 && iDb!=1 ){
/* If creating a temp table, the name may not be qualified. Unless
** the database name is "temp" anyway. */
sqlite3ErrorMsg(pParse, "temporary table name must be unqualified");
return;
}
if( !OMIT_TEMPDB && isTemp ) iDb = 1;
zName = sqlite3NameFromToken(db, pName);
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenMap(pParse, (void*)zName, pName);
}
}
pParse->sNameToken = *pName;
if( zName==0 ) return;
if( sqlite3CheckObjectName(pParse, zName, isView?"view":"table", zName) ){
goto begin_table_error;
}
if( db->init.iDb==1 ) isTemp = 1;
#ifndef SQLITE_OMIT_AUTHORIZATION
assert( isTemp==0 || isTemp==1 );
assert( isView==0 || isView==1 );
{
static const u8 aCode[] = {
SQLITE_CREATE_TABLE,
SQLITE_CREATE_TEMP_TABLE,
SQLITE_CREATE_VIEW,
SQLITE_CREATE_TEMP_VIEW
};
char *zDb = db->aDb[iDb].zDbSName;
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(isTemp), 0, zDb) ){
goto begin_table_error;
}
if( !isVirtual && sqlite3AuthCheck(pParse, (int)aCode[isTemp+2*isView],
zName, 0, zDb) ){
goto begin_table_error;
}
}
#endif
/* Make sure the new table name does not collide with an existing
** index or table name in the same database. Issue an error message if
** it does. The exception is if the statement being parsed was passed
** to an sqlite3_declare_vtab() call. In that case only the column names
** and types will be used, so there is no need to test for namespace
** collisions.
*/
if( !IN_SPECIAL_PARSE ){
char *zDb = db->aDb[iDb].zDbSName;
if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
goto begin_table_error;
}
pTable = sqlite3FindTable(db, zName, zDb);
if( pTable ){
if( !noErr ){
sqlite3ErrorMsg(pParse, "table %T already exists", pName);
}else{
assert( !db->init.busy || CORRUPT_DB );
sqlite3CodeVerifySchema(pParse, iDb);
}
goto begin_table_error;
}
if( sqlite3FindIndex(db, zName, zDb)!=0 ){
sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);
goto begin_table_error;
}
}
pTable = sqlite3DbMallocZero(db, sizeof(Table));
if( pTable==0 ){
assert( db->mallocFailed );
pParse->rc = SQLITE_NOMEM_BKPT;
pParse->nErr++;
goto begin_table_error;
}
pTable->zName = zName;
pTable->iPKey = -1;
pTable->pSchema = db->aDb[iDb].pSchema;
pTable->nTabRef = 1;
#ifdef SQLITE_DEFAULT_ROWEST
pTable->nRowLogEst = sqlite3LogEst(SQLITE_DEFAULT_ROWEST);
#else
pTable->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
#endif
assert( pParse->pNewTable==0 );
pParse->pNewTable = pTable;
/* If this is the magic sqlite_sequence table used by autoincrement,
** then record a pointer to this table in the main database structure
** so that INSERT can find the table easily.
*/
#ifndef SQLITE_OMIT_AUTOINCREMENT
if( !pParse->nested && strcmp(zName, "sqlite_sequence")==0 ){
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
pTable->pSchema->pSeqTab = pTable;
}
#endif
/* Begin generating the code that will insert the table record into
** the schema table. Note in particular that we must go ahead
** and allocate the record number for the table entry now. Before any
** PRIMARY KEY or UNIQUE keywords are parsed. Those keywords will cause
** indices to be created and the table record must come before the
** indices. Hence, the record number for the table must be allocated
** now.
*/
if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
int addr1;
int fileFormat;
int reg1, reg2, reg3;
/* nullRow[] is an OP_Record encoding of a row containing 5 NULLs */
static const char nullRow[] = { 6, 0, 0, 0, 0, 0 };
sqlite3BeginWriteOperation(pParse, 1, iDb);
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( isVirtual ){
sqlite3VdbeAddOp0(v, OP_VBegin);
}
#endif
/* If the file format and encoding in the database have not been set,
** set them now.
*/
reg1 = pParse->regRowid = ++pParse->nMem;
reg2 = pParse->regRoot = ++pParse->nMem;
reg3 = ++pParse->nMem;
sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, BTREE_FILE_FORMAT);
sqlite3VdbeUsesBtree(v, iDb);
addr1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);
fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
1 : SQLITE_MAX_FILE_FORMAT;
sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, fileFormat);
sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, ENC(db));
sqlite3VdbeJumpHere(v, addr1);
/* This just creates a place-holder record in the sqlite_schema table.
** The record created does not contain anything yet. It will be replaced
** by the real entry in code generated at sqlite3EndTable().
**
** The rowid for the new entry is left in register pParse->regRowid.
** The root page number of the new table is left in reg pParse->regRoot.
** The rowid and root page number values are needed by the code that
** sqlite3EndTable will generate.
*/
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
if( isView || isVirtual ){
sqlite3VdbeAddOp2(v, OP_Integer, 0, reg2);
}else
#endif
{
pParse->addrCrTab =
sqlite3VdbeAddOp3(v, OP_CreateBtree, iDb, reg2, BTREE_INTKEY);
}
sqlite3OpenSchemaTable(pParse, iDb);
sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
sqlite3VdbeAddOp4(v, OP_Blob, 6, reg3, 0, nullRow, P4_STATIC);
sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
sqlite3VdbeAddOp0(v, OP_Close);
}
/* Normal (non-error) return. */
return;
/* If an error occurs, we jump here */
begin_table_error:
sqlite3DbFree(db, zName);
return;
}
/* Set properties of a table column based on the (magical)
** name of the column.
*/
#if SQLITE_ENABLE_HIDDEN_COLUMNS
SQLITE_PRIVATE void sqlite3ColumnPropertiesFromName(Table *pTab, Column *pCol){
if( sqlite3_strnicmp(pCol->zName, "__hidden__", 10)==0 ){
pCol->colFlags |= COLFLAG_HIDDEN;
}else if( pTab && pCol!=pTab->aCol && (pCol[-1].colFlags & COLFLAG_HIDDEN) ){
pTab->tabFlags |= TF_OOOHidden;
}
}
#endif
/*
** Add a new column to the table currently being constructed.
**
** The parser calls this routine once for each column declaration
** in a CREATE TABLE statement. sqlite3StartTable() gets called
** first to get things going. Then this routine is called for each
** column.
*/
SQLITE_PRIVATE void sqlite3AddColumn(Parse *pParse, Token *pName, Token *pType){
Table *p;
int i;
char *z;
char *zType;
Column *pCol;
sqlite3 *db = pParse->db;
if( (p = pParse->pNewTable)==0 ) return;
if( p->nCol+1>db->aLimit[SQLITE_LIMIT_COLUMN] ){
sqlite3ErrorMsg(pParse, "too many columns on %s", p->zName);
return;
}
z = sqlite3DbMallocRaw(db, pName->n + pType->n + 2);
if( z==0 ) return;
if( IN_RENAME_OBJECT ) sqlite3RenameTokenMap(pParse, (void*)z, pName);
memcpy(z, pName->z, pName->n);
z[pName->n] = 0;
sqlite3Dequote(z);
for(i=0; i<p->nCol; i++){
if( sqlite3_stricmp(z, p->aCol[i].zName)==0 ){
sqlite3ErrorMsg(pParse, "duplicate column name: %s", z);
sqlite3DbFree(db, z);
return;
}
}
if( (p->nCol & 0x7)==0 ){
Column *aNew;
aNew = sqlite3DbRealloc(db,p->aCol,(p->nCol+8)*sizeof(p->aCol[0]));
if( aNew==0 ){
sqlite3DbFree(db, z);
return;
}
p->aCol = aNew;
}
pCol = &p->aCol[p->nCol];
memset(pCol, 0, sizeof(p->aCol[0]));
pCol->zName = z;
pCol->hName = sqlite3StrIHash(z);
sqlite3ColumnPropertiesFromName(p, pCol);
if( pType->n==0 ){
/* If there is no type specified, columns have the default affinity
** 'BLOB' with a default size of 4 bytes. */
pCol->affinity = SQLITE_AFF_BLOB;
pCol->szEst = 1;
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
if( 4>=sqlite3GlobalConfig.szSorterRef ){
pCol->colFlags |= COLFLAG_SORTERREF;
}
#endif
}else{
zType = z + sqlite3Strlen30(z) + 1;
memcpy(zType, pType->z, pType->n);
zType[pType->n] = 0;
sqlite3Dequote(zType);
pCol->affinity = sqlite3AffinityType(zType, pCol);
pCol->colFlags |= COLFLAG_HASTYPE;
}
p->nCol++;
p->nNVCol++;
pParse->constraintName.n = 0;
}
/*
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement. A "NOT NULL" constraint has
** been seen on a column. This routine sets the notNull flag on
** the column currently under construction.
*/
SQLITE_PRIVATE void sqlite3AddNotNull(Parse *pParse, int onError){
Table *p;
Column *pCol;
p = pParse->pNewTable;
if( p==0 || NEVER(p->nCol<1) ) return;
pCol = &p->aCol[p->nCol-1];
pCol->notNull = (u8)onError;
p->tabFlags |= TF_HasNotNull;
/* Set the uniqNotNull flag on any UNIQUE or PK indexes already created
** on this column. */
if( pCol->colFlags & COLFLAG_UNIQUE ){
Index *pIdx;
for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
assert( pIdx->nKeyCol==1 && pIdx->onError!=OE_None );
if( pIdx->aiColumn[0]==p->nCol-1 ){
pIdx->uniqNotNull = 1;
}
}
}
}
/*
** Scan the column type name zType (length nType) and return the
** associated affinity type.
**
** This routine does a case-independent search of zType for the
** substrings in the following table. If one of the substrings is
** found, the corresponding affinity is returned. If zType contains
** more than one of the substrings, entries toward the top of
** the table take priority. For example, if zType is 'BLOBINT',
** SQLITE_AFF_INTEGER is returned.
**
** Substring | Affinity
** --------------------------------
** 'INT' | SQLITE_AFF_INTEGER
** 'CHAR' | SQLITE_AFF_TEXT
** 'CLOB' | SQLITE_AFF_TEXT
** 'TEXT' | SQLITE_AFF_TEXT
** 'BLOB' | SQLITE_AFF_BLOB
** 'REAL' | SQLITE_AFF_REAL
** 'FLOA' | SQLITE_AFF_REAL
** 'DOUB' | SQLITE_AFF_REAL
**
** If none of the substrings in the above table are found,
** SQLITE_AFF_NUMERIC is returned.
*/
SQLITE_PRIVATE char sqlite3AffinityType(const char *zIn, Column *pCol){
u32 h = 0;
char aff = SQLITE_AFF_NUMERIC;
const char *zChar = 0;
assert( zIn!=0 );
while( zIn[0] ){
h = (h<<8) + sqlite3UpperToLower[(*zIn)&0xff];
zIn++;
if( h==(('c'<<24)+('h'<<16)+('a'<<8)+'r') ){ /* CHAR */
aff = SQLITE_AFF_TEXT;
zChar = zIn;
}else if( h==(('c'<<24)+('l'<<16)+('o'<<8)+'b') ){ /* CLOB */
aff = SQLITE_AFF_TEXT;
}else if( h==(('t'<<24)+('e'<<16)+('x'<<8)+'t') ){ /* TEXT */
aff = SQLITE_AFF_TEXT;
}else if( h==(('b'<<24)+('l'<<16)+('o'<<8)+'b') /* BLOB */
&& (aff==SQLITE_AFF_NUMERIC || aff==SQLITE_AFF_REAL) ){
aff = SQLITE_AFF_BLOB;
if( zIn[0]=='(' ) zChar = zIn;
#ifndef SQLITE_OMIT_FLOATING_POINT
}else if( h==(('r'<<24)+('e'<<16)+('a'<<8)+'l') /* REAL */
&& aff==SQLITE_AFF_NUMERIC ){
aff = SQLITE_AFF_REAL;
}else if( h==(('f'<<24)+('l'<<16)+('o'<<8)+'a') /* FLOA */
&& aff==SQLITE_AFF_NUMERIC ){
aff = SQLITE_AFF_REAL;
}else if( h==(('d'<<24)+('o'<<16)+('u'<<8)+'b') /* DOUB */
&& aff==SQLITE_AFF_NUMERIC ){
aff = SQLITE_AFF_REAL;
#endif
}else if( (h&0x00FFFFFF)==(('i'<<16)+('n'<<8)+'t') ){ /* INT */
aff = SQLITE_AFF_INTEGER;
break;
}
}
/* If pCol is not NULL, store an estimate of the field size. The
** estimate is scaled so that the size of an integer is 1. */
if( pCol ){
int v = 0; /* default size is approx 4 bytes */
if( aff<SQLITE_AFF_NUMERIC ){
if( zChar ){
while( zChar[0] ){
if( sqlite3Isdigit(zChar[0]) ){
/* BLOB(k), VARCHAR(k), CHAR(k) -> r=(k/4+1) */
sqlite3GetInt32(zChar, &v);
break;
}
zChar++;
}
}else{
v = 16; /* BLOB, TEXT, CLOB -> r=5 (approx 20 bytes)*/
}
}
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
if( v>=sqlite3GlobalConfig.szSorterRef ){
pCol->colFlags |= COLFLAG_SORTERREF;
}
#endif
v = v/4 + 1;
if( v>255 ) v = 255;
pCol->szEst = v;
}
return aff;
}
/*
** The expression is the default value for the most recently added column
** of the table currently under construction.
**
** Default value expressions must be constant. Raise an exception if this
** is not the case.
**
** This routine is called by the parser while in the middle of
** parsing a CREATE TABLE statement.
*/
SQLITE_PRIVATE void sqlite3AddDefaultValue(
Parse *pParse, /* Parsing context */
Expr *pExpr, /* The parsed expression of the default value */
const char *zStart, /* Start of the default value text */
const char *zEnd /* First character past end of defaut value text */
){
Table *p;
Column *pCol;
sqlite3 *db = pParse->db;
p = pParse->pNewTable;
if( p!=0 ){
int isInit = db->init.busy && db->init.iDb!=1;
pCol = &(p->aCol[p->nCol-1]);
if( !sqlite3ExprIsConstantOrFunction(pExpr, isInit) ){
sqlite3ErrorMsg(pParse, "default value of column [%s] is not constant",
pCol->zName);
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
}else if( pCol->colFlags & COLFLAG_GENERATED ){
testcase( pCol->colFlags & COLFLAG_VIRTUAL );
testcase( pCol->colFlags & COLFLAG_STORED );
sqlite3ErrorMsg(pParse, "cannot use DEFAULT on a generated column");
#endif
}else{
/* A copy of pExpr is used instead of the original, as pExpr contains
** tokens that point to volatile memory.
*/
Expr x;
sqlite3ExprDelete(db, pCol->pDflt);
memset(&x, 0, sizeof(x));
x.op = TK_SPAN;
x.u.zToken = sqlite3DbSpanDup(db, zStart, zEnd);
x.pLeft = pExpr;
x.flags = EP_Skip;
pCol->pDflt = sqlite3ExprDup(db, &x, EXPRDUP_REDUCE);
sqlite3DbFree(db, x.u.zToken);
}
}
if( IN_RENAME_OBJECT ){
sqlite3RenameExprUnmap(pParse, pExpr);
}
sqlite3ExprDelete(db, pExpr);
}
/*
** Backwards Compatibility Hack:
**
** Historical versions of SQLite accepted strings as column names in
** indexes and PRIMARY KEY constraints and in UNIQUE constraints. Example:
**
** CREATE TABLE xyz(a,b,c,d,e,PRIMARY KEY('a'),UNIQUE('b','c' COLLATE trim)
** CREATE INDEX abc ON xyz('c','d' DESC,'e' COLLATE nocase DESC);
**
** This is goofy. But to preserve backwards compatibility we continue to
** accept it. This routine does the necessary conversion. It converts
** the expression given in its argument from a TK_STRING into a TK_ID
** if the expression is just a TK_STRING with an optional COLLATE clause.
** If the expression is anything other than TK_STRING, the expression is
** unchanged.
*/
static void sqlite3StringToId(Expr *p){
if( p->op==TK_STRING ){
p->op = TK_ID;
}else if( p->op==TK_COLLATE && p->pLeft->op==TK_STRING ){
p->pLeft->op = TK_ID;
}
}
/*
** Tag the given column as being part of the PRIMARY KEY
*/
static void makeColumnPartOfPrimaryKey(Parse *pParse, Column *pCol){
pCol->colFlags |= COLFLAG_PRIMKEY;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( pCol->colFlags & COLFLAG_GENERATED ){
testcase( pCol->colFlags & COLFLAG_VIRTUAL );
testcase( pCol->colFlags & COLFLAG_STORED );
sqlite3ErrorMsg(pParse,
"generated columns cannot be part of the PRIMARY KEY");
}
#endif
}
/*
** Designate the PRIMARY KEY for the table. pList is a list of names
** of columns that form the primary key. If pList is NULL, then the
** most recently added column of the table is the primary key.
**
** A table can have at most one primary key. If the table already has
** a primary key (and this is the second primary key) then create an
** error.
**
** If the PRIMARY KEY is on a single column whose datatype is INTEGER,
** then we will try to use that column as the rowid. Set the Table.iPKey
** field of the table under construction to be the index of the
** INTEGER PRIMARY KEY column. Table.iPKey is set to -1 if there is
** no INTEGER PRIMARY KEY.
**
** If the key is not an INTEGER PRIMARY KEY, then create a unique
** index for the key. No index is created for INTEGER PRIMARY KEYs.
*/
SQLITE_PRIVATE void sqlite3AddPrimaryKey(
Parse *pParse, /* Parsing context */
ExprList *pList, /* List of field names to be indexed */
int onError, /* What to do with a uniqueness conflict */
int autoInc, /* True if the AUTOINCREMENT keyword is present */
int sortOrder /* SQLITE_SO_ASC or SQLITE_SO_DESC */
){
Table *pTab = pParse->pNewTable;
Column *pCol = 0;
int iCol = -1, i;
int nTerm;
if( pTab==0 ) goto primary_key_exit;
if( pTab->tabFlags & TF_HasPrimaryKey ){
sqlite3ErrorMsg(pParse,
"table \"%s\" has more than one primary key", pTab->zName);
goto primary_key_exit;
}
pTab->tabFlags |= TF_HasPrimaryKey;
if( pList==0 ){
iCol = pTab->nCol - 1;
pCol = &pTab->aCol[iCol];
makeColumnPartOfPrimaryKey(pParse, pCol);
nTerm = 1;
}else{
nTerm = pList->nExpr;
for(i=0; i<nTerm; i++){
Expr *pCExpr = sqlite3ExprSkipCollate(pList->a[i].pExpr);
assert( pCExpr!=0 );
sqlite3StringToId(pCExpr);
if( pCExpr->op==TK_ID ){
const char *zCName = pCExpr->u.zToken;
for(iCol=0; iCol<pTab->nCol; iCol++){
if( sqlite3StrICmp(zCName, pTab->aCol[iCol].zName)==0 ){
pCol = &pTab->aCol[iCol];
makeColumnPartOfPrimaryKey(pParse, pCol);
break;
}
}
}
}
}
if( nTerm==1
&& pCol
&& sqlite3StrICmp(sqlite3ColumnType(pCol,""), "INTEGER")==0
&& sortOrder!=SQLITE_SO_DESC
){
if( IN_RENAME_OBJECT && pList ){
Expr *pCExpr = sqlite3ExprSkipCollate(pList->a[0].pExpr);
sqlite3RenameTokenRemap(pParse, &pTab->iPKey, pCExpr);
}
pTab->iPKey = iCol;
pTab->keyConf = (u8)onError;
assert( autoInc==0 || autoInc==1 );
pTab->tabFlags |= autoInc*TF_Autoincrement;
if( pList ) pParse->iPkSortOrder = pList->a[0].sortFlags;
(void)sqlite3HasExplicitNulls(pParse, pList);
}else if( autoInc ){
#ifndef SQLITE_OMIT_AUTOINCREMENT
sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "
"INTEGER PRIMARY KEY");
#endif
}else{
sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0,
0, sortOrder, 0, SQLITE_IDXTYPE_PRIMARYKEY);
pList = 0;
}
primary_key_exit:
sqlite3ExprListDelete(pParse->db, pList);
return;
}
/*
** Add a new CHECK constraint to the table currently under construction.
*/
SQLITE_PRIVATE void sqlite3AddCheckConstraint(
Parse *pParse, /* Parsing context */
Expr *pCheckExpr, /* The check expression */
const char *zStart, /* Opening "(" */
const char *zEnd /* Closing ")" */
){
#ifndef SQLITE_OMIT_CHECK
Table *pTab = pParse->pNewTable;
sqlite3 *db = pParse->db;
if( pTab && !IN_DECLARE_VTAB
&& !sqlite3BtreeIsReadonly(db->aDb[db->init.iDb].pBt)
){
pTab->pCheck = sqlite3ExprListAppend(pParse, pTab->pCheck, pCheckExpr);
if( pParse->constraintName.n ){
sqlite3ExprListSetName(pParse, pTab->pCheck, &pParse->constraintName, 1);
}else{
Token t;
for(zStart++; sqlite3Isspace(zStart[0]); zStart++){}
while( sqlite3Isspace(zEnd[-1]) ){ zEnd--; }
t.z = zStart;
t.n = (int)(zEnd - t.z);
sqlite3ExprListSetName(pParse, pTab->pCheck, &t, 1);
}
}else
#endif
{
sqlite3ExprDelete(pParse->db, pCheckExpr);
}
}
/*
** Set the collation function of the most recently parsed table column
** to the CollSeq given.
*/
SQLITE_PRIVATE void sqlite3AddCollateType(Parse *pParse, Token *pToken){
Table *p;
int i;
char *zColl; /* Dequoted name of collation sequence */
sqlite3 *db;
if( (p = pParse->pNewTable)==0 || IN_RENAME_OBJECT ) return;
i = p->nCol-1;
db = pParse->db;
zColl = sqlite3NameFromToken(db, pToken);
if( !zColl ) return;
if( sqlite3LocateCollSeq(pParse, zColl) ){
Index *pIdx;
sqlite3DbFree(db, p->aCol[i].zColl);
p->aCol[i].zColl = zColl;
/* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
** then an index may have been created on this column before the
** collation type was added. Correct this if it is the case.
*/
for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
assert( pIdx->nKeyCol==1 );
if( pIdx->aiColumn[0]==i ){
pIdx->azColl[0] = p->aCol[i].zColl;
}
}
}else{
sqlite3DbFree(db, zColl);
}
}
/* Change the most recently parsed column to be a GENERATED ALWAYS AS
** column.
*/
SQLITE_PRIVATE void sqlite3AddGenerated(Parse *pParse, Expr *pExpr, Token *pType){
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
u8 eType = COLFLAG_VIRTUAL;
Table *pTab = pParse->pNewTable;
Column *pCol;
if( pTab==0 ){
/* generated column in an CREATE TABLE IF NOT EXISTS that already exists */
goto generated_done;
}
pCol = &(pTab->aCol[pTab->nCol-1]);
if( IN_DECLARE_VTAB ){
sqlite3ErrorMsg(pParse, "virtual tables cannot use computed columns");
goto generated_done;
}
if( pCol->pDflt ) goto generated_error;
if( pType ){
if( pType->n==7 && sqlite3StrNICmp("virtual",pType->z,7)==0 ){
/* no-op */
}else if( pType->n==6 && sqlite3StrNICmp("stored",pType->z,6)==0 ){
eType = COLFLAG_STORED;
}else{
goto generated_error;
}
}
if( eType==COLFLAG_VIRTUAL ) pTab->nNVCol--;
pCol->colFlags |= eType;
assert( TF_HasVirtual==COLFLAG_VIRTUAL );
assert( TF_HasStored==COLFLAG_STORED );
pTab->tabFlags |= eType;
if( pCol->colFlags & COLFLAG_PRIMKEY ){
makeColumnPartOfPrimaryKey(pParse, pCol); /* For the error message */
}
pCol->pDflt = pExpr;
pExpr = 0;
goto generated_done;
generated_error:
sqlite3ErrorMsg(pParse, "error in generated column \"%s\"",
pCol->zName);
generated_done:
sqlite3ExprDelete(pParse->db, pExpr);
#else
/* Throw and error for the GENERATED ALWAYS AS clause if the
** SQLITE_OMIT_GENERATED_COLUMNS compile-time option is used. */
sqlite3ErrorMsg(pParse, "generated columns not supported");
sqlite3ExprDelete(pParse->db, pExpr);
#endif
}
/*
** Generate code that will increment the schema cookie.
**
** The schema cookie is used to determine when the schema for the
** database changes. After each schema change, the cookie value
** changes. When a process first reads the schema it records the
** cookie. Thereafter, whenever it goes to access the database,
** it checks the cookie to make sure the schema has not changed
** since it was last read.
**
** This plan is not completely bullet-proof. It is possible for
** the schema to change multiple times and for the cookie to be
** set back to prior value. But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32. So we're safe enough.
**
** IMPLEMENTATION-OF: R-34230-56049 SQLite automatically increments
** the schema-version whenever the schema changes.
*/
SQLITE_PRIVATE void sqlite3ChangeCookie(Parse *pParse, int iDb){
sqlite3 *db = pParse->db;
Vdbe *v = pParse->pVdbe;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION,
(int)(1+(unsigned)db->aDb[iDb].pSchema->schema_cookie));
}
/*
** Measure the number of characters needed to output the given
** identifier. The number returned includes any quotes used
** but does not include the null terminator.
**
** The estimate is conservative. It might be larger that what is
** really needed.
*/
static int identLength(const char *z){
int n;
for(n=0; *z; n++, z++){
if( *z=='"' ){ n++; }
}
return n + 2;
}
/*
** The first parameter is a pointer to an output buffer. The second
** parameter is a pointer to an integer that contains the offset at
** which to write into the output buffer. This function copies the
** nul-terminated string pointed to by the third parameter, zSignedIdent,
** to the specified offset in the buffer and updates *pIdx to refer
** to the first byte after the last byte written before returning.
**
** If the string zSignedIdent consists entirely of alpha-numeric
** characters, does not begin with a digit and is not an SQL keyword,
** then it is copied to the output buffer exactly as it is. Otherwise,
** it is quoted using double-quotes.
*/
static void identPut(char *z, int *pIdx, char *zSignedIdent){
unsigned char *zIdent = (unsigned char*)zSignedIdent;
int i, j, needQuote;
i = *pIdx;
for(j=0; zIdent[j]; j++){
if( !sqlite3Isalnum(zIdent[j]) && zIdent[j]!='_' ) break;
}
needQuote = sqlite3Isdigit(zIdent[0])
|| sqlite3KeywordCode(zIdent, j)!=TK_ID
|| zIdent[j]!=0
|| j==0;
if( needQuote ) z[i++] = '"';
for(j=0; zIdent[j]; j++){
z[i++] = zIdent[j];
if( zIdent[j]=='"' ) z[i++] = '"';
}
if( needQuote ) z[i++] = '"';
z[i] = 0;
*pIdx = i;
}
/*
** Generate a CREATE TABLE statement appropriate for the given
** table. Memory to hold the text of the statement is obtained
** from sqliteMalloc() and must be freed by the calling function.
*/
static char *createTableStmt(sqlite3 *db, Table *p){
int i, k, n;
char *zStmt;
char *zSep, *zSep2, *zEnd;
Column *pCol;
n = 0;
for(pCol = p->aCol, i=0; i<p->nCol; i++, pCol++){
n += identLength(pCol->zName) + 5;
}
n += identLength(p->zName);
if( n<50 ){
zSep = "";
zSep2 = ",";
zEnd = ")";
}else{
zSep = "\n ";
zSep2 = ",\n ";
zEnd = "\n)";
}
n += 35 + 6*p->nCol;
zStmt = sqlite3DbMallocRaw(0, n);
if( zStmt==0 ){
sqlite3OomFault(db);
return 0;
}
sqlite3_snprintf(n, zStmt, "CREATE TABLE ");
k = sqlite3Strlen30(zStmt);
identPut(zStmt, &k, p->zName);
zStmt[k++] = '(';
for(pCol=p->aCol, i=0; i<p->nCol; i++, pCol++){
static const char * const azType[] = {
/* SQLITE_AFF_BLOB */ "",
/* SQLITE_AFF_TEXT */ " TEXT",
/* SQLITE_AFF_NUMERIC */ " NUM",
/* SQLITE_AFF_INTEGER */ " INT",
/* SQLITE_AFF_REAL */ " REAL"
};
int len;
const char *zType;
sqlite3_snprintf(n-k, &zStmt[k], zSep);
k += sqlite3Strlen30(&zStmt[k]);
zSep = zSep2;
identPut(zStmt, &k, pCol->zName);
assert( pCol->affinity-SQLITE_AFF_BLOB >= 0 );
assert( pCol->affinity-SQLITE_AFF_BLOB < ArraySize(azType) );
testcase( pCol->affinity==SQLITE_AFF_BLOB );
testcase( pCol->affinity==SQLITE_AFF_TEXT );
testcase( pCol->affinity==SQLITE_AFF_NUMERIC );
testcase( pCol->affinity==SQLITE_AFF_INTEGER );
testcase( pCol->affinity==SQLITE_AFF_REAL );
zType = azType[pCol->affinity - SQLITE_AFF_BLOB];
len = sqlite3Strlen30(zType);
assert( pCol->affinity==SQLITE_AFF_BLOB
|| pCol->affinity==sqlite3AffinityType(zType, 0) );
memcpy(&zStmt[k], zType, len);
k += len;
assert( k<=n );
}
sqlite3_snprintf(n-k, &zStmt[k], "%s", zEnd);
return zStmt;
}
/*
** Resize an Index object to hold N columns total. Return SQLITE_OK
** on success and SQLITE_NOMEM on an OOM error.
*/
static int resizeIndexObject(sqlite3 *db, Index *pIdx, int N){
char *zExtra;
int nByte;
if( pIdx->nColumn>=N ) return SQLITE_OK;
assert( pIdx->isResized==0 );
nByte = (sizeof(char*) + sizeof(LogEst) + sizeof(i16) + 1)*N;
zExtra = sqlite3DbMallocZero(db, nByte);
if( zExtra==0 ) return SQLITE_NOMEM_BKPT;
memcpy(zExtra, pIdx->azColl, sizeof(char*)*pIdx->nColumn);
pIdx->azColl = (const char**)zExtra;
zExtra += sizeof(char*)*N;
memcpy(zExtra, pIdx->aiRowLogEst, sizeof(LogEst)*(pIdx->nKeyCol+1));
pIdx->aiRowLogEst = (LogEst*)zExtra;
zExtra += sizeof(LogEst)*N;
memcpy(zExtra, pIdx->aiColumn, sizeof(i16)*pIdx->nColumn);
pIdx->aiColumn = (i16*)zExtra;
zExtra += sizeof(i16)*N;
memcpy(zExtra, pIdx->aSortOrder, pIdx->nColumn);
pIdx->aSortOrder = (u8*)zExtra;
pIdx->nColumn = N;
pIdx->isResized = 1;
return SQLITE_OK;
}
/*
** Estimate the total row width for a table.
*/
static void estimateTableWidth(Table *pTab){
unsigned wTable = 0;
const Column *pTabCol;
int i;
for(i=pTab->nCol, pTabCol=pTab->aCol; i>0; i--, pTabCol++){
wTable += pTabCol->szEst;
}
if( pTab->iPKey<0 ) wTable++;
pTab->szTabRow = sqlite3LogEst(wTable*4);
}
/*
** Estimate the average size of a row for an index.
*/
static void estimateIndexWidth(Index *pIdx){
unsigned wIndex = 0;
int i;
const Column *aCol = pIdx->pTable->aCol;
for(i=0; i<pIdx->nColumn; i++){
i16 x = pIdx->aiColumn[i];
assert( x<pIdx->pTable->nCol );
wIndex += x<0 ? 1 : aCol[pIdx->aiColumn[i]].szEst;
}
pIdx->szIdxRow = sqlite3LogEst(wIndex*4);
}
/* Return true if column number x is any of the first nCol entries of aiCol[].
** This is used to determine if the column number x appears in any of the
** first nCol entries of an index.
*/
static int hasColumn(const i16 *aiCol, int nCol, int x){
while( nCol-- > 0 ){
assert( aiCol[0]>=0 );
if( x==*(aiCol++) ){
return 1;
}
}
return 0;
}
/*
** Return true if any of the first nKey entries of index pIdx exactly
** match the iCol-th entry of pPk. pPk is always a WITHOUT ROWID
** PRIMARY KEY index. pIdx is an index on the same table. pIdx may
** or may not be the same index as pPk.
**
** The first nKey entries of pIdx are guaranteed to be ordinary columns,
** not a rowid or expression.
**
** This routine differs from hasColumn() in that both the column and the
** collating sequence must match for this routine, but for hasColumn() only
** the column name must match.
*/
static int isDupColumn(Index *pIdx, int nKey, Index *pPk, int iCol){
int i, j;
assert( nKey<=pIdx->nColumn );
assert( iCol<MAX(pPk->nColumn,pPk->nKeyCol) );
assert( pPk->idxType==SQLITE_IDXTYPE_PRIMARYKEY );
assert( pPk->pTable->tabFlags & TF_WithoutRowid );
assert( pPk->pTable==pIdx->pTable );
testcase( pPk==pIdx );
j = pPk->aiColumn[iCol];
assert( j!=XN_ROWID && j!=XN_EXPR );
for(i=0; i<nKey; i++){
assert( pIdx->aiColumn[i]>=0 || j>=0 );
if( pIdx->aiColumn[i]==j
&& sqlite3StrICmp(pIdx->azColl[i], pPk->azColl[iCol])==0
){
return 1;
}
}
return 0;
}
/* Recompute the colNotIdxed field of the Index.
**
** colNotIdxed is a bitmask that has a 0 bit representing each indexed
** columns that are within the first 63 columns of the table. The
** high-order bit of colNotIdxed is always 1. All unindexed columns
** of the table have a 1.
**
** 2019-10-24: For the purpose of this computation, virtual columns are
** not considered to be covered by the index, even if they are in the
** index, because we do not trust the logic in whereIndexExprTrans() to be
** able to find all instances of a reference to the indexed table column
** and convert them into references to the index. Hence we always want
** the actual table at hand in order to recompute the virtual column, if
** necessary.
**
** The colNotIdxed mask is AND-ed with the SrcList.a[].colUsed mask
** to determine if the index is covering index.
*/
static void recomputeColumnsNotIndexed(Index *pIdx){
Bitmask m = 0;
int j;
Table *pTab = pIdx->pTable;
for(j=pIdx->nColumn-1; j>=0; j--){
int x = pIdx->aiColumn[j];
if( x>=0 && (pTab->aCol[x].colFlags & COLFLAG_VIRTUAL)==0 ){
testcase( x==BMS-1 );
testcase( x==BMS-2 );
if( x<BMS-1 ) m |= MASKBIT(x);
}
}
pIdx->colNotIdxed = ~m;
assert( (pIdx->colNotIdxed>>63)==1 );
}
/*
** This routine runs at the end of parsing a CREATE TABLE statement that
** has a WITHOUT ROWID clause. The job of this routine is to convert both
** internal schema data structures and the generated VDBE code so that they
** are appropriate for a WITHOUT ROWID table instead of a rowid table.
** Changes include:
**
** (1) Set all columns of the PRIMARY KEY schema object to be NOT NULL.
** (2) Convert P3 parameter of the OP_CreateBtree from BTREE_INTKEY
** into BTREE_BLOBKEY.
** (3) Bypass the creation of the sqlite_schema table entry
** for the PRIMARY KEY as the primary key index is now
** identified by the sqlite_schema table entry of the table itself.
** (4) Set the Index.tnum of the PRIMARY KEY Index object in the
** schema to the rootpage from the main table.
** (5) Add all table columns to the PRIMARY KEY Index object
** so that the PRIMARY KEY is a covering index. The surplus
** columns are part of KeyInfo.nAllField and are not used for
** sorting or lookup or uniqueness checks.
** (6) Replace the rowid tail on all automatically generated UNIQUE
** indices with the PRIMARY KEY columns.
**
** For virtual tables, only (1) is performed.
*/
static void convertToWithoutRowidTable(Parse *pParse, Table *pTab){
Index *pIdx;
Index *pPk;
int nPk;
int nExtra;
int i, j;
sqlite3 *db = pParse->db;
Vdbe *v = pParse->pVdbe;
/* Mark every PRIMARY KEY column as NOT NULL (except for imposter tables)
*/
if( !db->init.imposterTable ){
for(i=0; i<pTab->nCol; i++){
if( (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){
pTab->aCol[i].notNull = OE_Abort;
}
}
pTab->tabFlags |= TF_HasNotNull;
}
/* Convert the P3 operand of the OP_CreateBtree opcode from BTREE_INTKEY
** into BTREE_BLOBKEY.
*/
if( pParse->addrCrTab ){
assert( v );
sqlite3VdbeChangeP3(v, pParse->addrCrTab, BTREE_BLOBKEY);
}
/* Locate the PRIMARY KEY index. Or, if this table was originally
** an INTEGER PRIMARY KEY table, create a new PRIMARY KEY index.
*/
if( pTab->iPKey>=0 ){
ExprList *pList;
Token ipkToken;
sqlite3TokenInit(&ipkToken, pTab->aCol[pTab->iPKey].zName);
pList = sqlite3ExprListAppend(pParse, 0,
sqlite3ExprAlloc(db, TK_ID, &ipkToken, 0));
if( pList==0 ) return;
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenRemap(pParse, pList->a[0].pExpr, &pTab->iPKey);
}
pList->a[0].sortFlags = pParse->iPkSortOrder;
assert( pParse->pNewTable==pTab );
pTab->iPKey = -1;
sqlite3CreateIndex(pParse, 0, 0, 0, pList, pTab->keyConf, 0, 0, 0, 0,
SQLITE_IDXTYPE_PRIMARYKEY);
if( db->mallocFailed || pParse->nErr ) return;
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk->nKeyCol==1 );
}else{
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
/*
** Remove all redundant columns from the PRIMARY KEY. For example, change
** "PRIMARY KEY(a,b,a,b,c,b,c,d)" into just "PRIMARY KEY(a,b,c,d)". Later
** code assumes the PRIMARY KEY contains no repeated columns.
*/
for(i=j=1; i<pPk->nKeyCol; i++){
if( isDupColumn(pPk, j, pPk, i) ){
pPk->nColumn--;
}else{
testcase( hasColumn(pPk->aiColumn, j, pPk->aiColumn[i]) );
pPk->azColl[j] = pPk->azColl[i];
pPk->aSortOrder[j] = pPk->aSortOrder[i];
pPk->aiColumn[j++] = pPk->aiColumn[i];
}
}
pPk->nKeyCol = j;
}
assert( pPk!=0 );
pPk->isCovering = 1;
if( !db->init.imposterTable ) pPk->uniqNotNull = 1;
nPk = pPk->nColumn = pPk->nKeyCol;
/* Bypass the creation of the PRIMARY KEY btree and the sqlite_schema
** table entry. This is only required if currently generating VDBE
** code for a CREATE TABLE (not when parsing one as part of reading
** a database schema). */
if( v && pPk->tnum>0 ){
assert( db->init.busy==0 );
sqlite3VdbeChangeOpcode(v, (int)pPk->tnum, OP_Goto);
}
/* The root page of the PRIMARY KEY is the table root page */
pPk->tnum = pTab->tnum;
/* Update the in-memory representation of all UNIQUE indices by converting
** the final rowid column into one or more columns of the PRIMARY KEY.
*/
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int n;
if( IsPrimaryKeyIndex(pIdx) ) continue;
for(i=n=0; i<nPk; i++){
if( !isDupColumn(pIdx, pIdx->nKeyCol, pPk, i) ){
testcase( hasColumn(pIdx->aiColumn, pIdx->nKeyCol, pPk->aiColumn[i]) );
n++;
}
}
if( n==0 ){
/* This index is a superset of the primary key */
pIdx->nColumn = pIdx->nKeyCol;
continue;
}
if( resizeIndexObject(db, pIdx, pIdx->nKeyCol+n) ) return;
for(i=0, j=pIdx->nKeyCol; i<nPk; i++){
if( !isDupColumn(pIdx, pIdx->nKeyCol, pPk, i) ){
testcase( hasColumn(pIdx->aiColumn, pIdx->nKeyCol, pPk->aiColumn[i]) );
pIdx->aiColumn[j] = pPk->aiColumn[i];
pIdx->azColl[j] = pPk->azColl[i];
if( pPk->aSortOrder[i] ){
/* See ticket https://www.sqlite.org/src/info/bba7b69f9849b5bf */
pIdx->bAscKeyBug = 1;
}
j++;
}
}
assert( pIdx->nColumn>=pIdx->nKeyCol+n );
assert( pIdx->nColumn>=j );
}
/* Add all table columns to the PRIMARY KEY index
*/
nExtra = 0;
for(i=0; i<pTab->nCol; i++){
if( !hasColumn(pPk->aiColumn, nPk, i)
&& (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0 ) nExtra++;
}
if( resizeIndexObject(db, pPk, nPk+nExtra) ) return;
for(i=0, j=nPk; i<pTab->nCol; i++){
if( !hasColumn(pPk->aiColumn, j, i)
&& (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0
){
assert( j<pPk->nColumn );
pPk->aiColumn[j] = i;
pPk->azColl[j] = sqlite3StrBINARY;
j++;
}
}
assert( pPk->nColumn==j );
assert( pTab->nNVCol<=j );
recomputeColumnsNotIndexed(pPk);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Return true if pTab is a virtual table and zName is a shadow table name
** for that virtual table.
*/
SQLITE_PRIVATE int sqlite3IsShadowTableOf(sqlite3 *db, Table *pTab, const char *zName){
int nName; /* Length of zName */
Module *pMod; /* Module for the virtual table */
if( !IsVirtual(pTab) ) return 0;
nName = sqlite3Strlen30(pTab->zName);
if( sqlite3_strnicmp(zName, pTab->zName, nName)!=0 ) return 0;
if( zName[nName]!='_' ) return 0;
pMod = (Module*)sqlite3HashFind(&db->aModule, pTab->azModuleArg[0]);
if( pMod==0 ) return 0;
if( pMod->pModule->iVersion<3 ) return 0;
if( pMod->pModule->xShadowName==0 ) return 0;
return pMod->pModule->xShadowName(zName+nName+1);
}
#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Return true if zName is a shadow table name in the current database
** connection.
**
** zName is temporarily modified while this routine is running, but is
** restored to its original value prior to this routine returning.
*/
SQLITE_PRIVATE int sqlite3ShadowTableName(sqlite3 *db, const char *zName){
char *zTail; /* Pointer to the last "_" in zName */
Table *pTab; /* Table that zName is a shadow of */
zTail = strrchr(zName, '_');
if( zTail==0 ) return 0;
*zTail = 0;
pTab = sqlite3FindTable(db, zName, 0);
*zTail = '_';
if( pTab==0 ) return 0;
if( !IsVirtual(pTab) ) return 0;
return sqlite3IsShadowTableOf(db, pTab, zName);
}
#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
#ifdef SQLITE_DEBUG
/*
** Mark all nodes of an expression as EP_Immutable, indicating that
** they should not be changed. Expressions attached to a table or
** index definition are tagged this way to help ensure that we do
** not pass them into code generator routines by mistake.
*/
static int markImmutableExprStep(Walker *pWalker, Expr *pExpr){
ExprSetVVAProperty(pExpr, EP_Immutable);
return WRC_Continue;
}
static void markExprListImmutable(ExprList *pList){
if( pList ){
Walker w;
memset(&w, 0, sizeof(w));
w.xExprCallback = markImmutableExprStep;
w.xSelectCallback = sqlite3SelectWalkNoop;
w.xSelectCallback2 = 0;
sqlite3WalkExprList(&w, pList);
}
}
#else
#define markExprListImmutable(X) /* no-op */
#endif /* SQLITE_DEBUG */
/*
** This routine is called to report the final ")" that terminates
** a CREATE TABLE statement.
**
** The table structure that other action routines have been building
** is added to the internal hash tables, assuming no errors have
** occurred.
**
** An entry for the table is made in the schema table on disk, unless
** this is a temporary table or db->init.busy==1. When db->init.busy==1
** it means we are reading the sqlite_schema table because we just
** connected to the database or because the sqlite_schema table has
** recently changed, so the entry for this table already exists in
** the sqlite_schema table. We do not want to create it again.
**
** If the pSelect argument is not NULL, it means that this routine
** was called to create a table generated from a
** "CREATE TABLE ... AS SELECT ..." statement. The column names of
** the new table will match the result set of the SELECT.
*/
SQLITE_PRIVATE void sqlite3EndTable(
Parse *pParse, /* Parse context */
Token *pCons, /* The ',' token after the last column defn. */
Token *pEnd, /* The ')' before options in the CREATE TABLE */
u8 tabOpts, /* Extra table options. Usually 0. */
Select *pSelect /* Select from a "CREATE ... AS SELECT" */
){
Table *p; /* The new table */
sqlite3 *db = pParse->db; /* The database connection */
int iDb; /* Database in which the table lives */
Index *pIdx; /* An implied index of the table */
if( pEnd==0 && pSelect==0 ){
return;
}
assert( !db->mallocFailed );
p = pParse->pNewTable;
if( p==0 ) return;
if( pSelect==0 && sqlite3ShadowTableName(db, p->zName) ){
p->tabFlags |= TF_Shadow;
}
/* If the db->init.busy is 1 it means we are reading the SQL off the
** "sqlite_schema" or "sqlite_temp_schema" table on the disk.
** So do not write to the disk again. Extract the root page number
** for the table from the db->init.newTnum field. (The page number
** should have been put there by the sqliteOpenCb routine.)
**
** If the root page number is 1, that means this is the sqlite_schema
** table itself. So mark it read-only.
*/
if( db->init.busy ){
if( pSelect ){
sqlite3ErrorMsg(pParse, "");
return;
}
p->tnum = db->init.newTnum;
if( p->tnum==1 ) p->tabFlags |= TF_Readonly;
}
assert( (p->tabFlags & TF_HasPrimaryKey)==0
|| p->iPKey>=0 || sqlite3PrimaryKeyIndex(p)!=0 );
assert( (p->tabFlags & TF_HasPrimaryKey)!=0
|| (p->iPKey<0 && sqlite3PrimaryKeyIndex(p)==0) );
/* Special processing for WITHOUT ROWID Tables */
if( tabOpts & TF_WithoutRowid ){
if( (p->tabFlags & TF_Autoincrement) ){
sqlite3ErrorMsg(pParse,
"AUTOINCREMENT not allowed on WITHOUT ROWID tables");
return;
}
if( (p->tabFlags & TF_HasPrimaryKey)==0 ){
sqlite3ErrorMsg(pParse, "PRIMARY KEY missing on table %s", p->zName);
return;
}
p->tabFlags |= TF_WithoutRowid | TF_NoVisibleRowid;
convertToWithoutRowidTable(pParse, p);
}
iDb = sqlite3SchemaToIndex(db, p->pSchema);
#ifndef SQLITE_OMIT_CHECK
/* Resolve names in all CHECK constraint expressions.
*/
if( p->pCheck ){
sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck);
if( pParse->nErr ){
/* If errors are seen, delete the CHECK constraints now, else they might
** actually be used if PRAGMA writable_schema=ON is set. */
sqlite3ExprListDelete(db, p->pCheck);
p->pCheck = 0;
}else{
markExprListImmutable(p->pCheck);
}
}
#endif /* !defined(SQLITE_OMIT_CHECK) */
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( p->tabFlags & TF_HasGenerated ){
int ii, nNG = 0;
testcase( p->tabFlags & TF_HasVirtual );
testcase( p->tabFlags & TF_HasStored );
for(ii=0; ii<p->nCol; ii++){
u32 colFlags = p->aCol[ii].colFlags;
if( (colFlags & COLFLAG_GENERATED)!=0 ){
Expr *pX = p->aCol[ii].pDflt;
testcase( colFlags & COLFLAG_VIRTUAL );
testcase( colFlags & COLFLAG_STORED );
if( sqlite3ResolveSelfReference(pParse, p, NC_GenCol, pX, 0) ){
/* If there are errors in resolving the expression, change the
** expression to a NULL. This prevents code generators that operate
** on the expression from inserting extra parts into the expression
** tree that have been allocated from lookaside memory, which is
** illegal in a schema and will lead to errors or heap corruption
** when the database connection closes. */
sqlite3ExprDelete(db, pX);
p->aCol[ii].pDflt = sqlite3ExprAlloc(db, TK_NULL, 0, 0);
}
}else{
nNG++;
}
}
if( nNG==0 ){
sqlite3ErrorMsg(pParse, "must have at least one non-generated column");
return;
}
}
#endif
/* Estimate the average row size for the table and for all implied indices */
estimateTableWidth(p);
for(pIdx=p->pIndex; pIdx; pIdx=pIdx->pNext){
estimateIndexWidth(pIdx);
}
/* If not initializing, then create a record for the new table
** in the schema table of the database.
**
** If this is a TEMPORARY table, write the entry into the auxiliary
** file instead of into the main database file.
*/
if( !db->init.busy ){
int n;
Vdbe *v;
char *zType; /* "view" or "table" */
char *zType2; /* "VIEW" or "TABLE" */
char *zStmt; /* Text of the CREATE TABLE or CREATE VIEW statement */
v = sqlite3GetVdbe(pParse);
if( NEVER(v==0) ) return;
sqlite3VdbeAddOp1(v, OP_Close, 0);
/*
** Initialize zType for the new view or table.
*/
if( p->pSelect==0 ){
/* A regular table */
zType = "table";
zType2 = "TABLE";
#ifndef SQLITE_OMIT_VIEW
}else{
/* A view */
zType = "view";
zType2 = "VIEW";
#endif
}
/* If this is a CREATE TABLE xx AS SELECT ..., execute the SELECT
** statement to populate the new table. The root-page number for the
** new table is in register pParse->regRoot.
**
** Once the SELECT has been coded by sqlite3Select(), it is in a
** suitable state to query for the column names and types to be used
** by the new table.
**
** A shared-cache write-lock is not required to write to the new table,
** as a schema-lock must have already been obtained to create it. Since
** a schema-lock excludes all other database users, the write-lock would
** be redundant.
*/
if( pSelect ){
SelectDest dest; /* Where the SELECT should store results */
int regYield; /* Register holding co-routine entry-point */
int addrTop; /* Top of the co-routine */
int regRec; /* A record to be insert into the new table */
int regRowid; /* Rowid of the next row to insert */
int addrInsLoop; /* Top of the loop for inserting rows */
Table *pSelTab; /* A table that describes the SELECT results */
regYield = ++pParse->nMem;
regRec = ++pParse->nMem;
regRowid = ++pParse->nMem;
assert(pParse->nTab==1);
sqlite3MayAbort(pParse);
sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);
pParse->nTab = 2;
addrTop = sqlite3VdbeCurrentAddr(v) + 1;
sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
if( pParse->nErr ) return;
pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect, SQLITE_AFF_BLOB);
if( pSelTab==0 ) return;
assert( p->aCol==0 );
p->nCol = p->nNVCol = pSelTab->nCol;
p->aCol = pSelTab->aCol;
pSelTab->nCol = 0;
pSelTab->aCol = 0;
sqlite3DeleteTable(db, pSelTab);
sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
sqlite3Select(pParse, pSelect, &dest);
if( pParse->nErr ) return;
sqlite3VdbeEndCoroutine(v, regYield);
sqlite3VdbeJumpHere(v, addrTop - 1);
addrInsLoop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_MakeRecord, dest.iSdst, dest.nSdst, regRec);
sqlite3TableAffinity(v, p, 0);
sqlite3VdbeAddOp2(v, OP_NewRowid, 1, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, 1, regRec, regRowid);
sqlite3VdbeGoto(v, addrInsLoop);
sqlite3VdbeJumpHere(v, addrInsLoop);
sqlite3VdbeAddOp1(v, OP_Close, 1);
}
/* Compute the complete text of the CREATE statement */
if( pSelect ){
zStmt = createTableStmt(db, p);
}else{
Token *pEnd2 = tabOpts ? &pParse->sLastToken : pEnd;
n = (int)(pEnd2->z - pParse->sNameToken.z);
if( pEnd2->z[0]!=';' ) n += pEnd2->n;
zStmt = sqlite3MPrintf(db,
"CREATE %s %.*s", zType2, n, pParse->sNameToken.z
);
}
/* A slot for the record has already been allocated in the
** schema table. We just need to update that slot with all
** the information we've collected.
*/
sqlite3NestedParse(pParse,
"UPDATE %Q." DFLT_SCHEMA_TABLE
" SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q"
" WHERE rowid=#%d",
db->aDb[iDb].zDbSName,
zType,
p->zName,
p->zName,
pParse->regRoot,
zStmt,
pParse->regRowid
);
sqlite3DbFree(db, zStmt);
sqlite3ChangeCookie(pParse, iDb);
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* Check to see if we need to create an sqlite_sequence table for
** keeping track of autoincrement keys.
*/
if( (p->tabFlags & TF_Autoincrement)!=0 ){
Db *pDb = &db->aDb[iDb];
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( pDb->pSchema->pSeqTab==0 ){
sqlite3NestedParse(pParse,
"CREATE TABLE %Q.sqlite_sequence(name,seq)",
pDb->zDbSName
);
}
}
#endif
/* Reparse everything to update our internal data structures */
sqlite3VdbeAddParseSchemaOp(v, iDb,
sqlite3MPrintf(db, "tbl_name='%q' AND type!='trigger'", p->zName));
}
/* Add the table to the in-memory representation of the database.
*/
if( db->init.busy ){
Table *pOld;
Schema *pSchema = p->pSchema;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
pOld = sqlite3HashInsert(&pSchema->tblHash, p->zName, p);
if( pOld ){
assert( p==pOld ); /* Malloc must have failed inside HashInsert() */
sqlite3OomFault(db);
return;
}
pParse->pNewTable = 0;
db->mDbFlags |= DBFLAG_SchemaChange;
#ifndef SQLITE_OMIT_ALTERTABLE
if( !p->pSelect ){
const char *zName = (const char *)pParse->sNameToken.z;
int nName;
assert( !pSelect && pCons && pEnd );
if( pCons->z==0 ){
pCons = pEnd;
}
nName = (int)((const char *)pCons->z - zName);
p->addColOffset = 13 + sqlite3Utf8CharLen(zName, nName);
}
#endif
}
}
#ifndef SQLITE_OMIT_VIEW
/*
** The parser calls this routine in order to create a new VIEW
*/
SQLITE_PRIVATE void sqlite3CreateView(
Parse *pParse, /* The parsing context */
Token *pBegin, /* The CREATE token that begins the statement */
Token *pName1, /* The token that holds the name of the view */
Token *pName2, /* The token that holds the name of the view */
ExprList *pCNames, /* Optional list of view column names */
Select *pSelect, /* A SELECT statement that will become the new view */
int isTemp, /* TRUE for a TEMPORARY view */
int noErr /* Suppress error messages if VIEW already exists */
){
Table *p;
int n;
const char *z;
Token sEnd;
DbFixer sFix;
Token *pName = 0;
int iDb;
sqlite3 *db = pParse->db;
if( pParse->nVar>0 ){
sqlite3ErrorMsg(pParse, "parameters are not allowed in views");
goto create_view_fail;
}
sqlite3StartTable(pParse, pName1, pName2, isTemp, 1, 0, noErr);
p = pParse->pNewTable;
if( p==0 || pParse->nErr ) goto create_view_fail;
sqlite3TwoPartName(pParse, pName1, pName2, &pName);
iDb = sqlite3SchemaToIndex(db, p->pSchema);
sqlite3FixInit(&sFix, pParse, iDb, "view", pName);
if( sqlite3FixSelect(&sFix, pSelect) ) goto create_view_fail;
/* Make a copy of the entire SELECT statement that defines the view.
** This will force all the Expr.token.z values to be dynamically
** allocated rather than point to the input string - which means that
** they will persist after the current sqlite3_exec() call returns.
*/
pSelect->selFlags |= SF_View;
if( IN_RENAME_OBJECT ){
p->pSelect = pSelect;
pSelect = 0;
}else{
p->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
}
p->pCheck = sqlite3ExprListDup(db, pCNames, EXPRDUP_REDUCE);
if( db->mallocFailed ) goto create_view_fail;
/* Locate the end of the CREATE VIEW statement. Make sEnd point to
** the end.
*/
sEnd = pParse->sLastToken;
assert( sEnd.z[0]!=0 || sEnd.n==0 );
if( sEnd.z[0]!=';' ){
sEnd.z += sEnd.n;
}
sEnd.n = 0;
n = (int)(sEnd.z - pBegin->z);
assert( n>0 );
z = pBegin->z;
while( sqlite3Isspace(z[n-1]) ){ n--; }
sEnd.z = &z[n-1];
sEnd.n = 1;
/* Use sqlite3EndTable() to add the view to the schema table */
sqlite3EndTable(pParse, 0, &sEnd, 0, 0);
create_view_fail:
sqlite3SelectDelete(db, pSelect);
if( IN_RENAME_OBJECT ){
sqlite3RenameExprlistUnmap(pParse, pCNames);
}
sqlite3ExprListDelete(db, pCNames);
return;
}
#endif /* SQLITE_OMIT_VIEW */
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
/*
** The Table structure pTable is really a VIEW. Fill in the names of
** the columns of the view in the pTable structure. Return the number
** of errors. If an error is seen leave an error message in pParse->zErrMsg.
*/
SQLITE_PRIVATE int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
Table *pSelTab; /* A fake table from which we get the result set */
Select *pSel; /* Copy of the SELECT that implements the view */
int nErr = 0; /* Number of errors encountered */
int n; /* Temporarily holds the number of cursors assigned */
sqlite3 *db = pParse->db; /* Database connection for malloc errors */
#ifndef SQLITE_OMIT_VIRTUALTABLE
int rc;
#endif
#ifndef SQLITE_OMIT_AUTHORIZATION
sqlite3_xauth xAuth; /* Saved xAuth pointer */
#endif
assert( pTable );
#ifndef SQLITE_OMIT_VIRTUALTABLE
db->nSchemaLock++;
rc = sqlite3VtabCallConnect(pParse, pTable);
db->nSchemaLock--;
if( rc ){
return 1;
}
if( IsVirtual(pTable) ) return 0;
#endif
#ifndef SQLITE_OMIT_VIEW
/* A positive nCol means the columns names for this view are
** already known.
*/
if( pTable->nCol>0 ) return 0;
/* A negative nCol is a special marker meaning that we are currently
** trying to compute the column names. If we enter this routine with
** a negative nCol, it means two or more views form a loop, like this:
**
** CREATE VIEW one AS SELECT * FROM two;
** CREATE VIEW two AS SELECT * FROM one;
**
** Actually, the error above is now caught prior to reaching this point.
** But the following test is still important as it does come up
** in the following:
**
** CREATE TABLE main.ex1(a);
** CREATE TEMP VIEW ex1 AS SELECT a FROM ex1;
** SELECT * FROM temp.ex1;
*/
if( pTable->nCol<0 ){
sqlite3ErrorMsg(pParse, "view %s is circularly defined", pTable->zName);
return 1;
}
assert( pTable->nCol>=0 );
/* If we get this far, it means we need to compute the table names.
** Note that the call to sqlite3ResultSetOfSelect() will expand any
** "*" elements in the results set of the view and will assign cursors
** to the elements of the FROM clause. But we do not want these changes
** to be permanent. So the computation is done on a copy of the SELECT
** statement that defines the view.
*/
assert( pTable->pSelect );
pSel = sqlite3SelectDup(db, pTable->pSelect, 0);
if( pSel ){
u8 eParseMode = pParse->eParseMode;
pParse->eParseMode = PARSE_MODE_NORMAL;
n = pParse->nTab;
sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
pTable->nCol = -1;
DisableLookaside;
#ifndef SQLITE_OMIT_AUTHORIZATION
xAuth = db->xAuth;
db->xAuth = 0;
pSelTab = sqlite3ResultSetOfSelect(pParse, pSel, SQLITE_AFF_NONE);
db->xAuth = xAuth;
#else
pSelTab = sqlite3ResultSetOfSelect(pParse, pSel, SQLITE_AFF_NONE);
#endif
pParse->nTab = n;
if( pSelTab==0 ){
pTable->nCol = 0;
nErr++;
}else if( pTable->pCheck ){
/* CREATE VIEW name(arglist) AS ...
** The names of the columns in the table are taken from
** arglist which is stored in pTable->pCheck. The pCheck field
** normally holds CHECK constraints on an ordinary table, but for
** a VIEW it holds the list of column names.
*/
sqlite3ColumnsFromExprList(pParse, pTable->pCheck,
&pTable->nCol, &pTable->aCol);
if( db->mallocFailed==0
&& pParse->nErr==0
&& pTable->nCol==pSel->pEList->nExpr
){
sqlite3SelectAddColumnTypeAndCollation(pParse, pTable, pSel,
SQLITE_AFF_NONE);
}
}else{
/* CREATE VIEW name AS... without an argument list. Construct
** the column names from the SELECT statement that defines the view.
*/
assert( pTable->aCol==0 );
pTable->nCol = pSelTab->nCol;
pTable->aCol = pSelTab->aCol;
pSelTab->nCol = 0;
pSelTab->aCol = 0;
assert( sqlite3SchemaMutexHeld(db, 0, pTable->pSchema) );
}
pTable->nNVCol = pTable->nCol;
sqlite3DeleteTable(db, pSelTab);
sqlite3SelectDelete(db, pSel);
EnableLookaside;
pParse->eParseMode = eParseMode;
} else {
nErr++;
}
pTable->pSchema->schemaFlags |= DB_UnresetViews;
if( db->mallocFailed ){
sqlite3DeleteColumnNames(db, pTable);
pTable->aCol = 0;
pTable->nCol = 0;
}
#endif /* SQLITE_OMIT_VIEW */
return nErr;
}
#endif /* !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE) */
#ifndef SQLITE_OMIT_VIEW
/*
** Clear the column names from every VIEW in database idx.
*/
static void sqliteViewResetAll(sqlite3 *db, int idx){
HashElem *i;
assert( sqlite3SchemaMutexHeld(db, idx, 0) );
if( !DbHasProperty(db, idx, DB_UnresetViews) ) return;
for(i=sqliteHashFirst(&db->aDb[idx].pSchema->tblHash); i;i=sqliteHashNext(i)){
Table *pTab = sqliteHashData(i);
if( pTab->pSelect ){
sqlite3DeleteColumnNames(db, pTab);
pTab->aCol = 0;
pTab->nCol = 0;
}
}
DbClearProperty(db, idx, DB_UnresetViews);
}
#else
# define sqliteViewResetAll(A,B)
#endif /* SQLITE_OMIT_VIEW */
/*
** This function is called by the VDBE to adjust the internal schema
** used by SQLite when the btree layer moves a table root page. The
** root-page of a table or index in database iDb has changed from iFrom
** to iTo.
**
** Ticket #1728: The symbol table might still contain information
** on tables and/or indices that are the process of being deleted.
** If you are unlucky, one of those deleted indices or tables might
** have the same rootpage number as the real table or index that is
** being moved. So we cannot stop searching after the first match
** because the first match might be for one of the deleted indices
** or tables and not the table/index that is actually being moved.
** We must continue looping until all tables and indices with
** rootpage==iFrom have been converted to have a rootpage of iTo
** in order to be certain that we got the right one.
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
SQLITE_PRIVATE void sqlite3RootPageMoved(sqlite3 *db, int iDb, Pgno iFrom, Pgno iTo){
HashElem *pElem;
Hash *pHash;
Db *pDb;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
pDb = &db->aDb[iDb];
pHash = &pDb->pSchema->tblHash;
for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){
Table *pTab = sqliteHashData(pElem);
if( pTab->tnum==iFrom ){
pTab->tnum = iTo;
}
}
pHash = &pDb->pSchema->idxHash;
for(pElem=sqliteHashFirst(pHash); pElem; pElem=sqliteHashNext(pElem)){
Index *pIdx = sqliteHashData(pElem);
if( pIdx->tnum==iFrom ){
pIdx->tnum = iTo;
}
}
}
#endif
/*
** Write code to erase the table with root-page iTable from database iDb.
** Also write code to modify the sqlite_schema table and internal schema
** if a root-page of another table is moved by the btree-layer whilst
** erasing iTable (this can happen with an auto-vacuum database).
*/
static void destroyRootPage(Parse *pParse, int iTable, int iDb){
Vdbe *v = sqlite3GetVdbe(pParse);
int r1 = sqlite3GetTempReg(pParse);
if( iTable<2 ) sqlite3ErrorMsg(pParse, "corrupt schema");
sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);
sqlite3MayAbort(pParse);
#ifndef SQLITE_OMIT_AUTOVACUUM
/* OP_Destroy stores an in integer r1. If this integer
** is non-zero, then it is the root page number of a table moved to
** location iTable. The following code modifies the sqlite_schema table to
** reflect this.
**
** The "#NNN" in the SQL is a special constant that means whatever value
** is in register NNN. See grammar rules associated with the TK_REGISTER
** token for additional information.
*/
sqlite3NestedParse(pParse,
"UPDATE %Q." DFLT_SCHEMA_TABLE
" SET rootpage=%d WHERE #%d AND rootpage=#%d",
pParse->db->aDb[iDb].zDbSName, iTable, r1, r1);
#endif
sqlite3ReleaseTempReg(pParse, r1);
}
/*
** Write VDBE code to erase table pTab and all associated indices on disk.
** Code to update the sqlite_schema tables and internal schema definitions
** in case a root-page belonging to another table is moved by the btree layer
** is also added (this can happen with an auto-vacuum database).
*/
static void destroyTable(Parse *pParse, Table *pTab){
/* If the database may be auto-vacuum capable (if SQLITE_OMIT_AUTOVACUUM
** is not defined), then it is important to call OP_Destroy on the
** table and index root-pages in order, starting with the numerically
** largest root-page number. This guarantees that none of the root-pages
** to be destroyed is relocated by an earlier OP_Destroy. i.e. if the
** following were coded:
**
** OP_Destroy 4 0
** ...
** OP_Destroy 5 0
**
** and root page 5 happened to be the largest root-page number in the
** database, then root page 5 would be moved to page 4 by the
** "OP_Destroy 4 0" opcode. The subsequent "OP_Destroy 5 0" would hit
** a free-list page.
*/
Pgno iTab = pTab->tnum;
Pgno iDestroyed = 0;
while( 1 ){
Index *pIdx;
Pgno iLargest = 0;
if( iDestroyed==0 || iTab<iDestroyed ){
iLargest = iTab;
}
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
Pgno iIdx = pIdx->tnum;
assert( pIdx->pSchema==pTab->pSchema );
if( (iDestroyed==0 || (iIdx<iDestroyed)) && iIdx>iLargest ){
iLargest = iIdx;
}
}
if( iLargest==0 ){
return;
}else{
int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
assert( iDb>=0 && iDb<pParse->db->nDb );
destroyRootPage(pParse, iLargest, iDb);
iDestroyed = iLargest;
}
}
}
/*
** Remove entries from the sqlite_statN tables (for N in (1,2,3))
** after a DROP INDEX or DROP TABLE command.
*/
static void sqlite3ClearStatTables(
Parse *pParse, /* The parsing context */
int iDb, /* The database number */
const char *zType, /* "idx" or "tbl" */
const char *zName /* Name of index or table */
){
int i;
const char *zDbName = pParse->db->aDb[iDb].zDbSName;
for(i=1; i<=4; i++){
char zTab[24];
sqlite3_snprintf(sizeof(zTab),zTab,"sqlite_stat%d",i);
if( sqlite3FindTable(pParse->db, zTab, zDbName) ){
sqlite3NestedParse(pParse,
"DELETE FROM %Q.%s WHERE %s=%Q",
zDbName, zTab, zType, zName
);
}
}
}
/*
** Generate code to drop a table.
*/
SQLITE_PRIVATE void sqlite3CodeDropTable(Parse *pParse, Table *pTab, int iDb, int isView){
Vdbe *v;
sqlite3 *db = pParse->db;
Trigger *pTrigger;
Db *pDb = &db->aDb[iDb];
v = sqlite3GetVdbe(pParse);
assert( v!=0 );
sqlite3BeginWriteOperation(pParse, 1, iDb);
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
sqlite3VdbeAddOp0(v, OP_VBegin);
}
#endif
/* Drop all triggers associated with the table being dropped. Code
** is generated to remove entries from sqlite_schema and/or
** sqlite_temp_schema if required.
*/
pTrigger = sqlite3TriggerList(pParse, pTab);
while( pTrigger ){
assert( pTrigger->pSchema==pTab->pSchema ||
pTrigger->pSchema==db->aDb[1].pSchema );
sqlite3DropTriggerPtr(pParse, pTrigger);
pTrigger = pTrigger->pNext;
}
#ifndef SQLITE_OMIT_AUTOINCREMENT
/* Remove any entries of the sqlite_sequence table associated with
** the table being dropped. This is done before the table is dropped
** at the btree level, in case the sqlite_sequence table needs to
** move as a result of the drop (can happen in auto-vacuum mode).
*/
if( pTab->tabFlags & TF_Autoincrement ){
sqlite3NestedParse(pParse,
"DELETE FROM %Q.sqlite_sequence WHERE name=%Q",
pDb->zDbSName, pTab->zName
);
}
#endif
/* Drop all entries in the schema table that refer to the
** table. The program name loops through the schema table and deletes
** every row that refers to a table of the same name as the one being
** dropped. Triggers are handled separately because a trigger can be
** created in the temp database that refers to a table in another
** database.
*/
sqlite3NestedParse(pParse,
"DELETE FROM %Q." DFLT_SCHEMA_TABLE
" WHERE tbl_name=%Q and type!='trigger'",
pDb->zDbSName, pTab->zName);
if( !isView && !IsVirtual(pTab) ){
destroyTable(pParse, pTab);
}
/* Remove the table entry from SQLite's internal schema and modify
** the schema cookie.
*/
if( IsVirtual(pTab) ){
sqlite3VdbeAddOp4(v, OP_VDestroy, iDb, 0, 0, pTab->zName, 0);
sqlite3MayAbort(pParse);
}
sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);
sqlite3ChangeCookie(pParse, iDb);
sqliteViewResetAll(db, iDb);
}
/*
** Return TRUE if shadow tables should be read-only in the current
** context.
*/
SQLITE_PRIVATE int sqlite3ReadOnlyShadowTables(sqlite3 *db){
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( (db->flags & SQLITE_Defensive)!=0
&& db->pVtabCtx==0
&& db->nVdbeExec==0
){
return 1;
}
#endif
return 0;
}
/*
** Return true if it is not allowed to drop the given table
*/
static int tableMayNotBeDropped(sqlite3 *db, Table *pTab){
if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
if( sqlite3StrNICmp(pTab->zName+7, "stat", 4)==0 ) return 0;
if( sqlite3StrNICmp(pTab->zName+7, "parameters", 10)==0 ) return 0;
return 1;
}
if( (pTab->tabFlags & TF_Shadow)!=0 && sqlite3ReadOnlyShadowTables(db) ){
return 1;
}
return 0;
}
/*
** This routine is called to do the work of a DROP TABLE statement.
** pName is the name of the table to be dropped.
*/
SQLITE_PRIVATE void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){
Table *pTab;
Vdbe *v;
sqlite3 *db = pParse->db;
int iDb;
if( db->mallocFailed ){
goto exit_drop_table;
}
assert( pParse->nErr==0 );
assert( pName->nSrc==1 );
if( sqlite3ReadSchema(pParse) ) goto exit_drop_table;
if( noErr ) db->suppressErr++;
assert( isView==0 || isView==LOCATE_VIEW );
pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]);
if( noErr ) db->suppressErr--;
if( pTab==0 ){
if( noErr ) sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase);
goto exit_drop_table;
}
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( iDb>=0 && iDb<db->nDb );
/* If pTab is a virtual table, call ViewGetColumnNames() to ensure
** it is initialized.
*/
if( IsVirtual(pTab) && sqlite3ViewGetColumnNames(pParse, pTab) ){
goto exit_drop_table;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code;
const char *zTab = SCHEMA_TABLE(iDb);
const char *zDb = db->aDb[iDb].zDbSName;
const char *zArg2 = 0;
if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb)){
goto exit_drop_table;
}
if( isView ){
if( !OMIT_TEMPDB && iDb==1 ){
code = SQLITE_DROP_TEMP_VIEW;
}else{
code = SQLITE_DROP_VIEW;
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
}else if( IsVirtual(pTab) ){
code = SQLITE_DROP_VTABLE;
zArg2 = sqlite3GetVTable(db, pTab)->pMod->zName;
#endif
}else{
if( !OMIT_TEMPDB && iDb==1 ){
code = SQLITE_DROP_TEMP_TABLE;
}else{
code = SQLITE_DROP_TABLE;
}
}
if( sqlite3AuthCheck(pParse, code, pTab->zName, zArg2, zDb) ){
goto exit_drop_table;
}
if( sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb) ){
goto exit_drop_table;
}
}
#endif
if( tableMayNotBeDropped(db, pTab) ){
sqlite3ErrorMsg(pParse, "table %s may not be dropped", pTab->zName);
goto exit_drop_table;
}
#ifndef SQLITE_OMIT_VIEW
/* Ensure DROP TABLE is not used on a view, and DROP VIEW is not used
** on a table.
*/
if( isView && pTab->pSelect==0 ){
sqlite3ErrorMsg(pParse, "use DROP TABLE to delete table %s", pTab->zName);
goto exit_drop_table;
}
if( !isView && pTab->pSelect ){
sqlite3ErrorMsg(pParse, "use DROP VIEW to delete view %s", pTab->zName);
goto exit_drop_table;
}
#endif
/* Generate code to remove the table from the schema table
** on disk.
*/
v = sqlite3GetVdbe(pParse);
if( v ){
sqlite3BeginWriteOperation(pParse, 1, iDb);
if( !isView ){
sqlite3ClearStatTables(pParse, iDb, "tbl", pTab->zName);
sqlite3FkDropTable(pParse, pName, pTab);
}
sqlite3CodeDropTable(pParse, pTab, iDb, isView);
}
exit_drop_table:
sqlite3SrcListDelete(db, pName);
}
/*
** This routine is called to create a new foreign key on the table
** currently under construction. pFromCol determines which columns
** in the current table point to the foreign key. If pFromCol==0 then
** connect the key to the last column inserted. pTo is the name of
** the table referred to (a.k.a the "parent" table). pToCol is a list
** of tables in the parent pTo table. flags contains all
** information about the conflict resolution algorithms specified
** in the ON DELETE, ON UPDATE and ON INSERT clauses.
**
** An FKey structure is created and added to the table currently
** under construction in the pParse->pNewTable field.
**
** The foreign key is set for IMMEDIATE processing. A subsequent call
** to sqlite3DeferForeignKey() might change this to DEFERRED.
*/
SQLITE_PRIVATE void sqlite3CreateForeignKey(
Parse *pParse, /* Parsing context */
ExprList *pFromCol, /* Columns in this table that point to other table */
Token *pTo, /* Name of the other table */
ExprList *pToCol, /* Columns in the other table */
int flags /* Conflict resolution algorithms. */
){
sqlite3 *db = pParse->db;
#ifndef SQLITE_OMIT_FOREIGN_KEY
FKey *pFKey = 0;
FKey *pNextTo;
Table *p = pParse->pNewTable;
int nByte;
int i;
int nCol;
char *z;
assert( pTo!=0 );
if( p==0 || IN_DECLARE_VTAB ) goto fk_end;
if( pFromCol==0 ){
int iCol = p->nCol-1;
if( NEVER(iCol<0) ) goto fk_end;
if( pToCol && pToCol->nExpr!=1 ){
sqlite3ErrorMsg(pParse, "foreign key on %s"
" should reference only one column of table %T",
p->aCol[iCol].zName, pTo);
goto fk_end;
}
nCol = 1;
}else if( pToCol && pToCol->nExpr!=pFromCol->nExpr ){
sqlite3ErrorMsg(pParse,
"number of columns in foreign key does not match the number of "
"columns in the referenced table");
goto fk_end;
}else{
nCol = pFromCol->nExpr;
}
nByte = sizeof(*pFKey) + (nCol-1)*sizeof(pFKey->aCol[0]) + pTo->n + 1;
if( pToCol ){
for(i=0; i<pToCol->nExpr; i++){
nByte += sqlite3Strlen30(pToCol->a[i].zEName) + 1;
}
}
pFKey = sqlite3DbMallocZero(db, nByte );
if( pFKey==0 ){
goto fk_end;
}
pFKey->pFrom = p;
pFKey->pNextFrom = p->pFKey;
z = (char*)&pFKey->aCol[nCol];
pFKey->zTo = z;
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenMap(pParse, (void*)z, pTo);
}
memcpy(z, pTo->z, pTo->n);
z[pTo->n] = 0;
sqlite3Dequote(z);
z += pTo->n+1;
pFKey->nCol = nCol;
if( pFromCol==0 ){
pFKey->aCol[0].iFrom = p->nCol-1;
}else{
for(i=0; i<nCol; i++){
int j;
for(j=0; j<p->nCol; j++){
if( sqlite3StrICmp(p->aCol[j].zName, pFromCol->a[i].zEName)==0 ){
pFKey->aCol[i].iFrom = j;
break;
}
}
if( j>=p->nCol ){
sqlite3ErrorMsg(pParse,
"unknown column \"%s\" in foreign key definition",
pFromCol->a[i].zEName);
goto fk_end;
}
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenRemap(pParse, &pFKey->aCol[i], pFromCol->a[i].zEName);
}
}
}
if( pToCol ){
for(i=0; i<nCol; i++){
int n = sqlite3Strlen30(pToCol->a[i].zEName);
pFKey->aCol[i].zCol = z;
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenRemap(pParse, z, pToCol->a[i].zEName);
}
memcpy(z, pToCol->a[i].zEName, n);
z[n] = 0;
z += n+1;
}
}
pFKey->isDeferred = 0;
pFKey->aAction[0] = (u8)(flags & 0xff); /* ON DELETE action */
pFKey->aAction[1] = (u8)((flags >> 8 ) & 0xff); /* ON UPDATE action */
assert( sqlite3SchemaMutexHeld(db, 0, p->pSchema) );
pNextTo = (FKey *)sqlite3HashInsert(&p->pSchema->fkeyHash,
pFKey->zTo, (void *)pFKey
);
if( pNextTo==pFKey ){
sqlite3OomFault(db);
goto fk_end;
}
if( pNextTo ){
assert( pNextTo->pPrevTo==0 );
pFKey->pNextTo = pNextTo;
pNextTo->pPrevTo = pFKey;
}
/* Link the foreign key to the table as the last step.
*/
p->pFKey = pFKey;
pFKey = 0;
fk_end:
sqlite3DbFree(db, pFKey);
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
sqlite3ExprListDelete(db, pFromCol);
sqlite3ExprListDelete(db, pToCol);
}
/*
** This routine is called when an INITIALLY IMMEDIATE or INITIALLY DEFERRED
** clause is seen as part of a foreign key definition. The isDeferred
** parameter is 1 for INITIALLY DEFERRED and 0 for INITIALLY IMMEDIATE.
** The behavior of the most recently created foreign key is adjusted
** accordingly.
*/
SQLITE_PRIVATE void sqlite3DeferForeignKey(Parse *pParse, int isDeferred){
#ifndef SQLITE_OMIT_FOREIGN_KEY
Table *pTab;
FKey *pFKey;
if( (pTab = pParse->pNewTable)==0 || (pFKey = pTab->pFKey)==0 ) return;
assert( isDeferred==0 || isDeferred==1 ); /* EV: R-30323-21917 */
pFKey->isDeferred = (u8)isDeferred;
#endif
}
/*
** Generate code that will erase and refill index *pIdx. This is
** used to initialize a newly created index or to recompute the
** content of an index in response to a REINDEX command.
**
** if memRootPage is not negative, it means that the index is newly
** created. The register specified by memRootPage contains the
** root page number of the index. If memRootPage is negative, then
** the index already exists and must be cleared before being refilled and
** the root page number of the index is taken from pIndex->tnum.
*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
Table *pTab = pIndex->pTable; /* The table that is indexed */
int iTab = pParse->nTab++; /* Btree cursor used for pTab */
int iIdx = pParse->nTab++; /* Btree cursor used for pIndex */
int iSorter; /* Cursor opened by OpenSorter (if in use) */
int addr1; /* Address of top of loop */
int addr2; /* Address to jump to for next iteration */
Pgno tnum; /* Root page of index */
int iPartIdxLabel; /* Jump to this label to skip a row */
Vdbe *v; /* Generate code into this virtual machine */
KeyInfo *pKey; /* KeyInfo for index */
int regRecord; /* Register holding assembled index record */
sqlite3 *db = pParse->db; /* The database connection */
int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
#ifndef SQLITE_OMIT_AUTHORIZATION
if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
db->aDb[iDb].zDbSName ) ){
return;
}
#endif
/* Require a write-lock on the table to perform this operation */
sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
v = sqlite3GetVdbe(pParse);
if( v==0 ) return;
if( memRootPage>=0 ){
tnum = (Pgno)memRootPage;
}else{
tnum = pIndex->tnum;
}
pKey = sqlite3KeyInfoOfIndex(pParse, pIndex);
assert( pKey!=0 || db->mallocFailed || pParse->nErr );
/* Open the sorter cursor if we are to use one. */
iSorter = pParse->nTab++;
sqlite3VdbeAddOp4(v, OP_SorterOpen, iSorter, 0, pIndex->nKeyCol, (char*)
sqlite3KeyInfoRef(pKey), P4_KEYINFO);
/* Open the table. Loop through all rows of the table, inserting index
** records into the sorter. */
sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0); VdbeCoverage(v);
regRecord = sqlite3GetTempReg(pParse);
sqlite3MultiWrite(pParse);
sqlite3GenerateIndexKey(pParse,pIndex,iTab,regRecord,0,&iPartIdxLabel,0,0);
sqlite3VdbeAddOp2(v, OP_SorterInsert, iSorter, regRecord);
sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addr1);
if( memRootPage<0 ) sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);
sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, (int)tnum, iDb,
(char *)pKey, P4_KEYINFO);
sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR|((memRootPage>=0)?OPFLAG_P2ISREG:0));
addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0); VdbeCoverage(v);
if( IsUniqueIndex(pIndex) ){
int j2 = sqlite3VdbeGoto(v, 1);
addr2 = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeVerifyAbortable(v, OE_Abort);
sqlite3VdbeAddOp4Int(v, OP_SorterCompare, iSorter, j2, regRecord,
pIndex->nKeyCol); VdbeCoverage(v);
sqlite3UniqueConstraint(pParse, OE_Abort, pIndex);
sqlite3VdbeJumpHere(v, j2);
}else{
/* Most CREATE INDEX and REINDEX statements that are not UNIQUE can not
** abort. The exception is if one of the indexed expressions contains a
** user function that throws an exception when it is evaluated. But the
** overhead of adding a statement journal to a CREATE INDEX statement is
** very small (since most of the pages written do not contain content that
** needs to be restored if the statement aborts), so we call
** sqlite3MayAbort() for all CREATE INDEX statements. */
sqlite3MayAbort(pParse);
addr2 = sqlite3VdbeCurrentAddr(v);
}
sqlite3VdbeAddOp3(v, OP_SorterData, iSorter, regRecord, iIdx);
if( !pIndex->bAscKeyBug ){
/* This OP_SeekEnd opcode makes index insert for a REINDEX go much
** faster by avoiding unnecessary seeks. But the optimization does
** not work for UNIQUE constraint indexes on WITHOUT ROWID tables
** with DESC primary keys, since those indexes have there keys in
** a different order from the main table.
** See ticket: https://www.sqlite.org/src/info/bba7b69f9849b5bf
*/
sqlite3VdbeAddOp1(v, OP_SeekEnd, iIdx);
}
sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, regRecord);
sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
sqlite3ReleaseTempReg(pParse, regRecord);
sqlite3VdbeAddOp2(v, OP_SorterNext, iSorter, addr2); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addr1);
sqlite3VdbeAddOp1(v, OP_Close, iTab);
sqlite3VdbeAddOp1(v, OP_Close, iIdx);
sqlite3VdbeAddOp1(v, OP_Close, iSorter);
}
/*
** Allocate heap space to hold an Index object with nCol columns.
**
** Increase the allocation size to provide an extra nExtra bytes
** of 8-byte aligned space after the Index object and return a
** pointer to this extra space in *ppExtra.
*/
SQLITE_PRIVATE Index *sqlite3AllocateIndexObject(
sqlite3 *db, /* Database connection */
i16 nCol, /* Total number of columns in the index */
int nExtra, /* Number of bytes of extra space to alloc */
char **ppExtra /* Pointer to the "extra" space */
){
Index *p; /* Allocated index object */
int nByte; /* Bytes of space for Index object + arrays */
nByte = ROUND8(sizeof(Index)) + /* Index structure */
ROUND8(sizeof(char*)*nCol) + /* Index.azColl */
ROUND8(sizeof(LogEst)*(nCol+1) + /* Index.aiRowLogEst */
sizeof(i16)*nCol + /* Index.aiColumn */
sizeof(u8)*nCol); /* Index.aSortOrder */
p = sqlite3DbMallocZero(db, nByte + nExtra);
if( p ){
char *pExtra = ((char*)p)+ROUND8(sizeof(Index));
p->azColl = (const char**)pExtra; pExtra += ROUND8(sizeof(char*)*nCol);
p->aiRowLogEst = (LogEst*)pExtra; pExtra += sizeof(LogEst)*(nCol+1);
p->aiColumn = (i16*)pExtra; pExtra += sizeof(i16)*nCol;
p->aSortOrder = (u8*)pExtra;
p->nColumn = nCol;
p->nKeyCol = nCol - 1;
*ppExtra = ((char*)p) + nByte;
}
return p;
}
/*
** If expression list pList contains an expression that was parsed with
** an explicit "NULLS FIRST" or "NULLS LAST" clause, leave an error in
** pParse and return non-zero. Otherwise, return zero.
*/
SQLITE_PRIVATE int sqlite3HasExplicitNulls(Parse *pParse, ExprList *pList){
if( pList ){
int i;
for(i=0; i<pList->nExpr; i++){
if( pList->a[i].bNulls ){
u8 sf = pList->a[i].sortFlags;
sqlite3ErrorMsg(pParse, "unsupported use of NULLS %s",
(sf==0 || sf==3) ? "FIRST" : "LAST"
);
return 1;
}
}
}
return 0;
}
/*
** Create a new index for an SQL table. pName1.pName2 is the name of the index
** and pTblList is the name of the table that is to be indexed. Both will
** be NULL for a primary key or an index that is created to satisfy a
** UNIQUE constraint. If pTable and pIndex are NULL, use pParse->pNewTable
** as the table to be indexed. pParse->pNewTable is a table that is
** currently being constructed by a CREATE TABLE statement.
**
** pList is a list of columns to be indexed. pList will be NULL if this
** is a primary key or unique-constraint on the most recent column added
** to the table currently under construction.
*/
SQLITE_PRIVATE void sqlite3CreateIndex(
Parse *pParse, /* All information about this parse */
Token *pName1, /* First part of index name. May be NULL */
Token *pName2, /* Second part of index name. May be NULL */
SrcList *pTblName, /* Table to index. Use pParse->pNewTable if 0 */
ExprList *pList, /* A list of columns to be indexed */
int onError, /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
Token *pStart, /* The CREATE token that begins this statement */
Expr *pPIWhere, /* WHERE clause for partial indices */
int sortOrder, /* Sort order of primary key when pList==NULL */
int ifNotExist, /* Omit error if index already exists */
u8 idxType /* The index type */
){
Table *pTab = 0; /* Table to be indexed */
Index *pIndex = 0; /* The index to be created */
char *zName = 0; /* Name of the index */
int nName; /* Number of characters in zName */
int i, j;
DbFixer sFix; /* For assigning database names to pTable */
int sortOrderMask; /* 1 to honor DESC in index. 0 to ignore. */
sqlite3 *db = pParse->db;
Db *pDb; /* The specific table containing the indexed database */
int iDb; /* Index of the database that is being written */
Token *pName = 0; /* Unqualified name of the index to create */
struct ExprList_item *pListItem; /* For looping over pList */
int nExtra = 0; /* Space allocated for zExtra[] */
int nExtraCol; /* Number of extra columns needed */
char *zExtra = 0; /* Extra space after the Index object */
Index *pPk = 0; /* PRIMARY KEY index for WITHOUT ROWID tables */
if( db->mallocFailed || pParse->nErr>0 ){
goto exit_create_index;
}
if( IN_DECLARE_VTAB && idxType!=SQLITE_IDXTYPE_PRIMARYKEY ){
goto exit_create_index;
}
if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
goto exit_create_index;
}
if( sqlite3HasExplicitNulls(pParse, pList) ){
goto exit_create_index;
}
/*
** Find the table that is to be indexed. Return early if not found.
*/
if( pTblName!=0 ){
/* Use the two-part index name to determine the database
** to search for the table. 'Fix' the table name to this db
** before looking up the table.
*/
assert( pName1 && pName2 );
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
if( iDb<0 ) goto exit_create_index;
assert( pName && pName->z );
#ifndef SQLITE_OMIT_TEMPDB
/* If the index name was unqualified, check if the table
** is a temp table. If so, set the database to 1. Do not do this
** if initialising a database schema.
*/
if( !db->init.busy ){
pTab = sqlite3SrcListLookup(pParse, pTblName);
if( pName2->n==0 && pTab && pTab->pSchema==db->aDb[1].pSchema ){
iDb = 1;
}
}
#endif
sqlite3FixInit(&sFix, pParse, iDb, "index", pName);
if( sqlite3FixSrcList(&sFix, pTblName) ){
/* Because the parser constructs pTblName from a single identifier,
** sqlite3FixSrcList can never fail. */
assert(0);
}
pTab = sqlite3LocateTableItem(pParse, 0, &pTblName->a[0]);
assert( db->mallocFailed==0 || pTab==0 );
if( pTab==0 ) goto exit_create_index;
if( iDb==1 && db->aDb[iDb].pSchema!=pTab->pSchema ){
sqlite3ErrorMsg(pParse,
"cannot create a TEMP index on non-TEMP table \"%s\"",
pTab->zName);
goto exit_create_index;
}
if( !HasRowid(pTab) ) pPk = sqlite3PrimaryKeyIndex(pTab);
}else{
assert( pName==0 );
assert( pStart==0 );
pTab = pParse->pNewTable;
if( !pTab ) goto exit_create_index;
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
}
pDb = &db->aDb[iDb];
assert( pTab!=0 );
assert( pParse->nErr==0 );
if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0
&& db->init.busy==0
&& pTblName!=0
#if SQLITE_USER_AUTHENTICATION
&& sqlite3UserAuthTable(pTab->zName)==0
#endif
){
sqlite3ErrorMsg(pParse, "table %s may not be indexed", pTab->zName);
goto exit_create_index;
}
#ifndef SQLITE_OMIT_VIEW
if( pTab->pSelect ){
sqlite3ErrorMsg(pParse, "views may not be indexed");
goto exit_create_index;
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
sqlite3ErrorMsg(pParse, "virtual tables may not be indexed");
goto exit_create_index;
}
#endif
/*
** Find the name of the index. Make sure there is not already another
** index or table with the same name.
**
** Exception: If we are reading the names of permanent indices from the
** sqlite_schema table (because some other process changed the schema) and
** one of the index names collides with the name of a temporary table or
** index, then we will continue to process this index.
**
** If pName==0 it means that we are
** dealing with a primary key or UNIQUE constraint. We have to invent our
** own name.
*/
if( pName ){
zName = sqlite3NameFromToken(db, pName);
if( zName==0 ) goto exit_create_index;
assert( pName->z!=0 );
if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName,"index",pTab->zName) ){
goto exit_create_index;
}
if( !IN_RENAME_OBJECT ){
if( !db->init.busy ){
if( sqlite3FindTable(db, zName, 0)!=0 ){
sqlite3ErrorMsg(pParse, "there is already a table named %s", zName);
goto exit_create_index;
}
}
if( sqlite3FindIndex(db, zName, pDb->zDbSName)!=0 ){
if( !ifNotExist ){
sqlite3ErrorMsg(pParse, "index %s already exists", zName);
}else{
assert( !db->init.busy );
sqlite3CodeVerifySchema(pParse, iDb);
}
goto exit_create_index;
}
}
}else{
int n;
Index *pLoop;
for(pLoop=pTab->pIndex, n=1; pLoop; pLoop=pLoop->pNext, n++){}
zName = sqlite3MPrintf(db, "sqlite_autoindex_%s_%d", pTab->zName, n);
if( zName==0 ){
goto exit_create_index;
}
/* Automatic index names generated from within sqlite3_declare_vtab()
** must have names that are distinct from normal automatic index names.
** The following statement converts "sqlite3_autoindex..." into
** "sqlite3_butoindex..." in order to make the names distinct.
** The "vtab_err.test" test demonstrates the need of this statement. */
if( IN_SPECIAL_PARSE ) zName[7]++;
}
/* Check for authorization to create an index.
*/
#ifndef SQLITE_OMIT_AUTHORIZATION
if( !IN_RENAME_OBJECT ){
const char *zDb = pDb->zDbSName;
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iDb), 0, zDb) ){
goto exit_create_index;
}
i = SQLITE_CREATE_INDEX;
if( !OMIT_TEMPDB && iDb==1 ) i = SQLITE_CREATE_TEMP_INDEX;
if( sqlite3AuthCheck(pParse, i, zName, pTab->zName, zDb) ){
goto exit_create_index;
}
}
#endif
/* If pList==0, it means this routine was called to make a primary
** key out of the last column added to the table under construction.
** So create a fake list to simulate this.
*/
if( pList==0 ){
Token prevCol;
Column *pCol = &pTab->aCol[pTab->nCol-1];
pCol->colFlags |= COLFLAG_UNIQUE;
sqlite3TokenInit(&prevCol, pCol->zName);
pList = sqlite3ExprListAppend(pParse, 0,
sqlite3ExprAlloc(db, TK_ID, &prevCol, 0));
if( pList==0 ) goto exit_create_index;
assert( pList->nExpr==1 );
sqlite3ExprListSetSortOrder(pList, sortOrder, SQLITE_SO_UNDEFINED);
}else{
sqlite3ExprListCheckLength(pParse, pList, "index");
if( pParse->nErr ) goto exit_create_index;
}
/* Figure out how many bytes of space are required to store explicitly
** specified collation sequence names.
*/
for(i=0; i<pList->nExpr; i++){
Expr *pExpr = pList->a[i].pExpr;
assert( pExpr!=0 );
if( pExpr->op==TK_COLLATE ){
nExtra += (1 + sqlite3Strlen30(pExpr->u.zToken));
}
}
/*
** Allocate the index structure.
*/
nName = sqlite3Strlen30(zName);
nExtraCol = pPk ? pPk->nKeyCol : 1;
assert( pList->nExpr + nExtraCol <= 32767 /* Fits in i16 */ );
pIndex = sqlite3AllocateIndexObject(db, pList->nExpr + nExtraCol,
nName + nExtra + 1, &zExtra);
if( db->mallocFailed ){
goto exit_create_index;
}
assert( EIGHT_BYTE_ALIGNMENT(pIndex->aiRowLogEst) );
assert( EIGHT_BYTE_ALIGNMENT(pIndex->azColl) );
pIndex->zName = zExtra;
zExtra += nName + 1;
memcpy(pIndex->zName, zName, nName+1);
pIndex->pTable = pTab;
pIndex->onError = (u8)onError;
pIndex->uniqNotNull = onError!=OE_None;
pIndex->idxType = idxType;
pIndex->pSchema = db->aDb[iDb].pSchema;
pIndex->nKeyCol = pList->nExpr;
if( pPIWhere ){
sqlite3ResolveSelfReference(pParse, pTab, NC_PartIdx, pPIWhere, 0);
pIndex->pPartIdxWhere = pPIWhere;
pPIWhere = 0;
}
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
/* Check to see if we should honor DESC requests on index columns
*/
if( pDb->pSchema->file_format>=4 ){
sortOrderMask = -1; /* Honor DESC */
}else{
sortOrderMask = 0; /* Ignore DESC */
}
/* Analyze the list of expressions that form the terms of the index and
** report any errors. In the common case where the expression is exactly
** a table column, store that column in aiColumn[]. For general expressions,
** populate pIndex->aColExpr and store XN_EXPR (-2) in aiColumn[].
**
** TODO: Issue a warning if two or more columns of the index are identical.
** TODO: Issue a warning if the table primary key is used as part of the
** index key.
*/
pListItem = pList->a;
if( IN_RENAME_OBJECT ){
pIndex->aColExpr = pList;
pList = 0;
}
for(i=0; i<pIndex->nKeyCol; i++, pListItem++){
Expr *pCExpr; /* The i-th index expression */
int requestedSortOrder; /* ASC or DESC on the i-th expression */
const char *zColl; /* Collation sequence name */
sqlite3StringToId(pListItem->pExpr);
sqlite3ResolveSelfReference(pParse, pTab, NC_IdxExpr, pListItem->pExpr, 0);
if( pParse->nErr ) goto exit_create_index;
pCExpr = sqlite3ExprSkipCollate(pListItem->pExpr);
if( pCExpr->op!=TK_COLUMN ){
if( pTab==pParse->pNewTable ){
sqlite3ErrorMsg(pParse, "expressions prohibited in PRIMARY KEY and "
"UNIQUE constraints");
goto exit_create_index;
}
if( pIndex->aColExpr==0 ){
pIndex->aColExpr = pList;
pList = 0;
}
j = XN_EXPR;
pIndex->aiColumn[i] = XN_EXPR;
pIndex->uniqNotNull = 0;
}else{
j = pCExpr->iColumn;
assert( j<=0x7fff );
if( j<0 ){
j = pTab->iPKey;
}else{
if( pTab->aCol[j].notNull==0 ){
pIndex->uniqNotNull = 0;
}
if( pTab->aCol[j].colFlags & COLFLAG_VIRTUAL ){
pIndex->bHasVCol = 1;
}
}
pIndex->aiColumn[i] = (i16)j;
}
zColl = 0;
if( pListItem->pExpr->op==TK_COLLATE ){
int nColl;
zColl = pListItem->pExpr->u.zToken;
nColl = sqlite3Strlen30(zColl) + 1;
assert( nExtra>=nColl );
memcpy(zExtra, zColl, nColl);
zColl = zExtra;
zExtra += nColl;
nExtra -= nColl;
}else if( j>=0 ){
zColl = pTab->aCol[j].zColl;
}
if( !zColl ) zColl = sqlite3StrBINARY;
if( !db->init.busy && !sqlite3LocateCollSeq(pParse, zColl) ){
goto exit_create_index;
}
pIndex->azColl[i] = zColl;
requestedSortOrder = pListItem->sortFlags & sortOrderMask;
pIndex->aSortOrder[i] = (u8)requestedSortOrder;
}
/* Append the table key to the end of the index. For WITHOUT ROWID
** tables (when pPk!=0) this will be the declared PRIMARY KEY. For
** normal tables (when pPk==0) this will be the rowid.
*/
if( pPk ){
for(j=0; j<pPk->nKeyCol; j++){
int x = pPk->aiColumn[j];
assert( x>=0 );
if( isDupColumn(pIndex, pIndex->nKeyCol, pPk, j) ){
pIndex->nColumn--;
}else{
testcase( hasColumn(pIndex->aiColumn,pIndex->nKeyCol,x) );
pIndex->aiColumn[i] = x;
pIndex->azColl[i] = pPk->azColl[j];
pIndex->aSortOrder[i] = pPk->aSortOrder[j];
i++;
}
}
assert( i==pIndex->nColumn );
}else{
pIndex->aiColumn[i] = XN_ROWID;
pIndex->azColl[i] = sqlite3StrBINARY;
}
sqlite3DefaultRowEst(pIndex);
if( pParse->pNewTable==0 ) estimateIndexWidth(pIndex);
/* If this index contains every column of its table, then mark
** it as a covering index */
assert( HasRowid(pTab)
|| pTab->iPKey<0 || sqlite3TableColumnToIndex(pIndex, pTab->iPKey)>=0 );
recomputeColumnsNotIndexed(pIndex);
if( pTblName!=0 && pIndex->nColumn>=pTab->nCol ){
pIndex->isCovering = 1;
for(j=0; j<pTab->nCol; j++){
if( j==pTab->iPKey ) continue;
if( sqlite3TableColumnToIndex(pIndex,j)>=0 ) continue;
pIndex->isCovering = 0;
break;
}
}
if( pTab==pParse->pNewTable ){
/* This routine has been called to create an automatic index as a
** result of a PRIMARY KEY or UNIQUE clause on a column definition, or
** a PRIMARY KEY or UNIQUE clause following the column definitions.
** i.e. one of:
**
** CREATE TABLE t(x PRIMARY KEY, y);
** CREATE TABLE t(x, y, UNIQUE(x, y));
**
** Either way, check to see if the table already has such an index. If
** so, don't bother creating this one. This only applies to
** automatically created indices. Users can do as they wish with
** explicit indices.
**
** Two UNIQUE or PRIMARY KEY constraints are considered equivalent
** (and thus suppressing the second one) even if they have different
** sort orders.
**
** If there are different collating sequences or if the columns of
** the constraint occur in different orders, then the constraints are
** considered distinct and both result in separate indices.
*/
Index *pIdx;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int k;
assert( IsUniqueIndex(pIdx) );
assert( pIdx->idxType!=SQLITE_IDXTYPE_APPDEF );
assert( IsUniqueIndex(pIndex) );
if( pIdx->nKeyCol!=pIndex->nKeyCol ) continue;
for(k=0; k<pIdx->nKeyCol; k++){
const char *z1;
const char *z2;
assert( pIdx->aiColumn[k]>=0 );
if( pIdx->aiColumn[k]!=pIndex->aiColumn[k] ) break;
z1 = pIdx->azColl[k];
z2 = pIndex->azColl[k];
if( sqlite3StrICmp(z1, z2) ) break;
}
if( k==pIdx->nKeyCol ){
if( pIdx->onError!=pIndex->onError ){
/* This constraint creates the same index as a previous
** constraint specified somewhere in the CREATE TABLE statement.
** However the ON CONFLICT clauses are different. If both this
** constraint and the previous equivalent constraint have explicit
** ON CONFLICT clauses this is an error. Otherwise, use the
** explicitly specified behavior for the index.
*/
if( !(pIdx->onError==OE_Default || pIndex->onError==OE_Default) ){
sqlite3ErrorMsg(pParse,
"conflicting ON CONFLICT clauses specified", 0);
}
if( pIdx->onError==OE_Default ){
pIdx->onError = pIndex->onError;
}
}
if( idxType==SQLITE_IDXTYPE_PRIMARYKEY ) pIdx->idxType = idxType;
if( IN_RENAME_OBJECT ){
pIndex->pNext = pParse->pNewIndex;
pParse->pNewIndex = pIndex;
pIndex = 0;
}
goto exit_create_index;
}
}
}
if( !IN_RENAME_OBJECT ){
/* Link the new Index structure to its table and to the other
** in-memory database structures.
*/
assert( pParse->nErr==0 );
if( db->init.busy ){
Index *p;
assert( !IN_SPECIAL_PARSE );
assert( sqlite3SchemaMutexHeld(db, 0, pIndex->pSchema) );
if( pTblName!=0 ){
pIndex->tnum = db->init.newTnum;
if( sqlite3IndexHasDuplicateRootPage(pIndex) ){
sqlite3ErrorMsg(pParse, "invalid rootpage");
pParse->rc = SQLITE_CORRUPT_BKPT;
goto exit_create_index;
}
}
p = sqlite3HashInsert(&pIndex->pSchema->idxHash,
pIndex->zName, pIndex);
if( p ){
assert( p==pIndex ); /* Malloc must have failed */
sqlite3OomFault(db);
goto exit_create_index;
}
db->mDbFlags |= DBFLAG_SchemaChange;
}
/* If this is the initial CREATE INDEX statement (or CREATE TABLE if the
** index is an implied index for a UNIQUE or PRIMARY KEY constraint) then
** emit code to allocate the index rootpage on disk and make an entry for
** the index in the sqlite_schema table and populate the index with
** content. But, do not do this if we are simply reading the sqlite_schema
** table to parse the schema, or if this index is the PRIMARY KEY index
** of a WITHOUT ROWID table.
**
** If pTblName==0 it means this index is generated as an implied PRIMARY KEY
** or UNIQUE index in a CREATE TABLE statement. Since the table
** has just been created, it contains no data and the index initialization
** step can be skipped.
*/
else if( HasRowid(pTab) || pTblName!=0 ){
Vdbe *v;
char *zStmt;
int iMem = ++pParse->nMem;
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto exit_create_index;
sqlite3BeginWriteOperation(pParse, 1, iDb);
/* Create the rootpage for the index using CreateIndex. But before
** doing so, code a Noop instruction and store its address in
** Index.tnum. This is required in case this index is actually a
** PRIMARY KEY and the table is actually a WITHOUT ROWID table. In
** that case the convertToWithoutRowidTable() routine will replace
** the Noop with a Goto to jump over the VDBE code generated below. */
pIndex->tnum = (Pgno)sqlite3VdbeAddOp0(v, OP_Noop);
sqlite3VdbeAddOp3(v, OP_CreateBtree, iDb, iMem, BTREE_BLOBKEY);
/* Gather the complete text of the CREATE INDEX statement into
** the zStmt variable
*/
assert( pName!=0 || pStart==0 );
if( pStart ){
int n = (int)(pParse->sLastToken.z - pName->z) + pParse->sLastToken.n;
if( pName->z[n-1]==';' ) n--;
/* A named index with an explicit CREATE INDEX statement */
zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
onError==OE_None ? "" : " UNIQUE", n, pName->z);
}else{
/* An automatic index created by a PRIMARY KEY or UNIQUE constraint */
/* zStmt = sqlite3MPrintf(""); */
zStmt = 0;
}
/* Add an entry in sqlite_schema for this index
*/
sqlite3NestedParse(pParse,
"INSERT INTO %Q." DFLT_SCHEMA_TABLE " VALUES('index',%Q,%Q,#%d,%Q);",
db->aDb[iDb].zDbSName,
pIndex->zName,
pTab->zName,
iMem,
zStmt
);
sqlite3DbFree(db, zStmt);
/* Fill the index with data and reparse the schema. Code an OP_Expire
** to invalidate all pre-compiled statements.
*/
if( pTblName ){
sqlite3RefillIndex(pParse, pIndex, iMem);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddParseSchemaOp(v, iDb,
sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName));
sqlite3VdbeAddOp2(v, OP_Expire, 0, 1);
}
sqlite3VdbeJumpHere(v, (int)pIndex->tnum);
}
}
if( db->init.busy || pTblName==0 ){
pIndex->pNext = pTab->pIndex;
pTab->pIndex = pIndex;
pIndex = 0;
}
else if( IN_RENAME_OBJECT ){
assert( pParse->pNewIndex==0 );
pParse->pNewIndex = pIndex;
pIndex = 0;
}
/* Clean up before exiting */
exit_create_index:
if( pIndex ) sqlite3FreeIndex(db, pIndex);
if( pTab ){ /* Ensure all REPLACE indexes are at the end of the list */
Index **ppFrom = &pTab->pIndex;
Index *pThis;
for(ppFrom=&pTab->pIndex; (pThis = *ppFrom)!=0; ppFrom=&pThis->pNext){
Index *pNext;
if( pThis->onError!=OE_Replace ) continue;
while( (pNext = pThis->pNext)!=0 && pNext->onError!=OE_Replace ){
*ppFrom = pNext;
pThis->pNext = pNext->pNext;
pNext->pNext = pThis;
ppFrom = &pNext->pNext;
}
break;
}
}
sqlite3ExprDelete(db, pPIWhere);
sqlite3ExprListDelete(db, pList);
sqlite3SrcListDelete(db, pTblName);
sqlite3DbFree(db, zName);
}
/*
** Fill the Index.aiRowEst[] array with default information - information
** to be used when we have not run the ANALYZE command.
**
** aiRowEst[0] is supposed to contain the number of elements in the index.
** Since we do not know, guess 1 million. aiRowEst[1] is an estimate of the
** number of rows in the table that match any particular value of the
** first column of the index. aiRowEst[2] is an estimate of the number
** of rows that match any particular combination of the first 2 columns
** of the index. And so forth. It must always be the case that
*
** aiRowEst[N]<=aiRowEst[N-1]
** aiRowEst[N]>=1
**
** Apart from that, we have little to go on besides intuition as to
** how aiRowEst[] should be initialized. The numbers generated here
** are based on typical values found in actual indices.
*/
SQLITE_PRIVATE void sqlite3DefaultRowEst(Index *pIdx){
/* 10, 9, 8, 7, 6 */
static const LogEst aVal[] = { 33, 32, 30, 28, 26 };
LogEst *a = pIdx->aiRowLogEst;
LogEst x;
int nCopy = MIN(ArraySize(aVal), pIdx->nKeyCol);
int i;
/* Indexes with default row estimates should not have stat1 data */
assert( !pIdx->hasStat1 );
/* Set the first entry (number of rows in the index) to the estimated
** number of rows in the table, or half the number of rows in the table
** for a partial index.
**
** 2020-05-27: If some of the stat data is coming from the sqlite_stat1
** table but other parts we are having to guess at, then do not let the
** estimated number of rows in the table be less than 1000 (LogEst 99).
** Failure to do this can cause the indexes for which we do not have
** stat1 data to be ignored by the query planner.
*/
x = pIdx->pTable->nRowLogEst;
assert( 99==sqlite3LogEst(1000) );
if( x<99 ){
pIdx->pTable->nRowLogEst = x = 99;
}
if( pIdx->pPartIdxWhere!=0 ) x -= 10; assert( 10==sqlite3LogEst(2) );
a[0] = x;
/* Estimate that a[1] is 10, a[2] is 9, a[3] is 8, a[4] is 7, a[5] is
** 6 and each subsequent value (if any) is 5. */
memcpy(&a[1], aVal, nCopy*sizeof(LogEst));
for(i=nCopy+1; i<=pIdx->nKeyCol; i++){
a[i] = 23; assert( 23==sqlite3LogEst(5) );
}
assert( 0==sqlite3LogEst(1) );
if( IsUniqueIndex(pIdx) ) a[pIdx->nKeyCol] = 0;
}
/*
** This routine will drop an existing named index. This routine
** implements the DROP INDEX statement.
*/
SQLITE_PRIVATE void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists){
Index *pIndex;
Vdbe *v;
sqlite3 *db = pParse->db;
int iDb;
assert( pParse->nErr==0 ); /* Never called with prior errors */
if( db->mallocFailed ){
goto exit_drop_index;
}
assert( pName->nSrc==1 );
if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
goto exit_drop_index;
}
pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);
if( pIndex==0 ){
if( !ifExists ){
sqlite3ErrorMsg(pParse, "no such index: %S", pName, 0);
}else{
sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase);
}
pParse->checkSchema = 1;
goto exit_drop_index;
}
if( pIndex->idxType!=SQLITE_IDXTYPE_APPDEF ){
sqlite3ErrorMsg(pParse, "index associated with UNIQUE "
"or PRIMARY KEY constraint cannot be dropped", 0);
goto exit_drop_index;
}
iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int code = SQLITE_DROP_INDEX;
Table *pTab = pIndex->pTable;
const char *zDb = db->aDb[iDb].zDbSName;
const char *zTab = SCHEMA_TABLE(iDb);
if( sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
goto exit_drop_index;
}
if( !OMIT_TEMPDB && iDb ) code = SQLITE_DROP_TEMP_INDEX;
if( sqlite3AuthCheck(pParse, code, pIndex->zName, pTab->zName, zDb) ){
goto exit_drop_index;
}
}
#endif
/* Generate code to remove the index and from the schema table */
v = sqlite3GetVdbe(pParse);
if( v ){
sqlite3BeginWriteOperation(pParse, 1, iDb);
sqlite3NestedParse(pParse,
"DELETE FROM %Q." DFLT_SCHEMA_TABLE " WHERE name=%Q AND type='index'",
db->aDb[iDb].zDbSName, pIndex->zName
);
sqlite3ClearStatTables(pParse, iDb, "idx", pIndex->zName);
sqlite3ChangeCookie(pParse, iDb);
destroyRootPage(pParse, pIndex->tnum, iDb);
sqlite3VdbeAddOp4(v, OP_DropIndex, iDb, 0, 0, pIndex->zName, 0);
}
exit_drop_index:
sqlite3SrcListDelete(db, pName);
}
/*
** pArray is a pointer to an array of objects. Each object in the
** array is szEntry bytes in size. This routine uses sqlite3DbRealloc()
** to extend the array so that there is space for a new object at the end.
**
** When this function is called, *pnEntry contains the current size of
** the array (in entries - so the allocation is ((*pnEntry) * szEntry) bytes
** in total).
**
** If the realloc() is successful (i.e. if no OOM condition occurs), the
** space allocated for the new object is zeroed, *pnEntry updated to
** reflect the new size of the array and a pointer to the new allocation
** returned. *pIdx is set to the index of the new array entry in this case.
**
** Otherwise, if the realloc() fails, *pIdx is set to -1, *pnEntry remains
** unchanged and a copy of pArray returned.
*/
SQLITE_PRIVATE void *sqlite3ArrayAllocate(
sqlite3 *db, /* Connection to notify of malloc failures */
void *pArray, /* Array of objects. Might be reallocated */
int szEntry, /* Size of each object in the array */
int *pnEntry, /* Number of objects currently in use */
int *pIdx /* Write the index of a new slot here */
){
char *z;
sqlite3_int64 n = *pIdx = *pnEntry;
if( (n & (n-1))==0 ){
sqlite3_int64 sz = (n==0) ? 1 : 2*n;
void *pNew = sqlite3DbRealloc(db, pArray, sz*szEntry);
if( pNew==0 ){
*pIdx = -1;
return pArray;
}
pArray = pNew;
}
z = (char*)pArray;
memset(&z[n * szEntry], 0, szEntry);
++*pnEntry;
return pArray;
}
/*
** Append a new element to the given IdList. Create a new IdList if
** need be.
**
** A new IdList is returned, or NULL if malloc() fails.
*/
SQLITE_PRIVATE IdList *sqlite3IdListAppend(Parse *pParse, IdList *pList, Token *pToken){
sqlite3 *db = pParse->db;
int i;
if( pList==0 ){
pList = sqlite3DbMallocZero(db, sizeof(IdList) );
if( pList==0 ) return 0;
}
pList->a = sqlite3ArrayAllocate(
db,
pList->a,
sizeof(pList->a[0]),
&pList->nId,
&i
);
if( i<0 ){
sqlite3IdListDelete(db, pList);
return 0;
}
pList->a[i].zName = sqlite3NameFromToken(db, pToken);
if( IN_RENAME_OBJECT && pList->a[i].zName ){
sqlite3RenameTokenMap(pParse, (void*)pList->a[i].zName, pToken);
}
return pList;
}
/*
** Delete an IdList.
*/
SQLITE_PRIVATE void sqlite3IdListDelete(sqlite3 *db, IdList *pList){
int i;
if( pList==0 ) return;
for(i=0; i<pList->nId; i++){
sqlite3DbFree(db, pList->a[i].zName);
}
sqlite3DbFree(db, pList->a);
sqlite3DbFreeNN(db, pList);
}
/*
** Return the index in pList of the identifier named zId. Return -1
** if not found.
*/
SQLITE_PRIVATE int sqlite3IdListIndex(IdList *pList, const char *zName){
int i;
if( pList==0 ) return -1;
for(i=0; i<pList->nId; i++){
if( sqlite3StrICmp(pList->a[i].zName, zName)==0 ) return i;
}
return -1;
}
/*
** Maximum size of a SrcList object.
** The SrcList object is used to represent the FROM clause of a
** SELECT statement, and the query planner cannot deal with more
** than 64 tables in a join. So any value larger than 64 here
** is sufficient for most uses. Smaller values, like say 10, are
** appropriate for small and memory-limited applications.
*/
#ifndef SQLITE_MAX_SRCLIST
# define SQLITE_MAX_SRCLIST 200
#endif
/*
** Expand the space allocated for the given SrcList object by
** creating nExtra new slots beginning at iStart. iStart is zero based.
** New slots are zeroed.
**
** For example, suppose a SrcList initially contains two entries: A,B.
** To append 3 new entries onto the end, do this:
**
** sqlite3SrcListEnlarge(db, pSrclist, 3, 2);
**
** After the call above it would contain: A, B, nil, nil, nil.
** If the iStart argument had been 1 instead of 2, then the result
** would have been: A, nil, nil, nil, B. To prepend the new slots,
** the iStart value would be 0. The result then would
** be: nil, nil, nil, A, B.
**
** If a memory allocation fails or the SrcList becomes too large, leave
** the original SrcList unchanged, return NULL, and leave an error message
** in pParse.
*/
SQLITE_PRIVATE SrcList *sqlite3SrcListEnlarge(
Parse *pParse, /* Parsing context into which errors are reported */
SrcList *pSrc, /* The SrcList to be enlarged */
int nExtra, /* Number of new slots to add to pSrc->a[] */
int iStart /* Index in pSrc->a[] of first new slot */
){
int i;
/* Sanity checking on calling parameters */
assert( iStart>=0 );
assert( nExtra>=1 );
assert( pSrc!=0 );
assert( iStart<=pSrc->nSrc );
/* Allocate additional space if needed */
if( (u32)pSrc->nSrc+nExtra>pSrc->nAlloc ){
SrcList *pNew;
sqlite3_int64 nAlloc = 2*(sqlite3_int64)pSrc->nSrc+nExtra;
sqlite3 *db = pParse->db;
if( pSrc->nSrc+nExtra>=SQLITE_MAX_SRCLIST ){
sqlite3ErrorMsg(pParse, "too many FROM clause terms, max: %d",
SQLITE_MAX_SRCLIST);
return 0;
}
if( nAlloc>SQLITE_MAX_SRCLIST ) nAlloc = SQLITE_MAX_SRCLIST;
pNew = sqlite3DbRealloc(db, pSrc,
sizeof(*pSrc) + (nAlloc-1)*sizeof(pSrc->a[0]) );
if( pNew==0 ){
assert( db->mallocFailed );
return 0;
}
pSrc = pNew;
pSrc->nAlloc = nAlloc;
}
/* Move existing slots that come after the newly inserted slots
** out of the way */
for(i=pSrc->nSrc-1; i>=iStart; i--){
pSrc->a[i+nExtra] = pSrc->a[i];
}
pSrc->nSrc += nExtra;
/* Zero the newly allocated slots */
memset(&pSrc->a[iStart], 0, sizeof(pSrc->a[0])*nExtra);
for(i=iStart; i<iStart+nExtra; i++){
pSrc->a[i].iCursor = -1;
}
/* Return a pointer to the enlarged SrcList */
return pSrc;
}
/*
** Append a new table name to the given SrcList. Create a new SrcList if
** need be. A new entry is created in the SrcList even if pTable is NULL.
**
** A SrcList is returned, or NULL if there is an OOM error or if the
** SrcList grows to large. The returned
** SrcList might be the same as the SrcList that was input or it might be
** a new one. If an OOM error does occurs, then the prior value of pList
** that is input to this routine is automatically freed.
**
** If pDatabase is not null, it means that the table has an optional
** database name prefix. Like this: "database.table". The pDatabase
** points to the table name and the pTable points to the database name.
** The SrcList.a[].zName field is filled with the table name which might
** come from pTable (if pDatabase is NULL) or from pDatabase.
** SrcList.a[].zDatabase is filled with the database name from pTable,
** or with NULL if no database is specified.
**
** In other words, if call like this:
**
** sqlite3SrcListAppend(D,A,B,0);
**
** Then B is a table name and the database name is unspecified. If called
** like this:
**
** sqlite3SrcListAppend(D,A,B,C);
**
** Then C is the table name and B is the database name. If C is defined
** then so is B. In other words, we never have a case where:
**
** sqlite3SrcListAppend(D,A,0,C);
**
** Both pTable and pDatabase are assumed to be quoted. They are dequoted
** before being added to the SrcList.
*/
SQLITE_PRIVATE SrcList *sqlite3SrcListAppend(
Parse *pParse, /* Parsing context, in which errors are reported */
SrcList *pList, /* Append to this SrcList. NULL creates a new SrcList */
Token *pTable, /* Table to append */
Token *pDatabase /* Database of the table */
){
struct SrcList_item *pItem;
sqlite3 *db;
assert( pDatabase==0 || pTable!=0 ); /* Cannot have C without B */
assert( pParse!=0 );
assert( pParse->db!=0 );
db = pParse->db;
if( pList==0 ){
pList = sqlite3DbMallocRawNN(pParse->db, sizeof(SrcList) );
if( pList==0 ) return 0;
pList->nAlloc = 1;
pList->nSrc = 1;
memset(&pList->a[0], 0, sizeof(pList->a[0]));
pList->a[0].iCursor = -1;
}else{
SrcList *pNew = sqlite3SrcListEnlarge(pParse, pList, 1, pList->nSrc);
if( pNew==0 ){
sqlite3SrcListDelete(db, pList);
return 0;
}else{
pList = pNew;
}
}
pItem = &pList->a[pList->nSrc-1];
if( pDatabase && pDatabase->z==0 ){
pDatabase = 0;
}
if( pDatabase ){
pItem->zName = sqlite3NameFromToken(db, pDatabase);
pItem->zDatabase = sqlite3NameFromToken(db, pTable);
}else{
pItem->zName = sqlite3NameFromToken(db, pTable);
pItem->zDatabase = 0;
}
return pList;
}
/*
** Assign VdbeCursor index numbers to all tables in a SrcList
*/
SQLITE_PRIVATE void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){
int i;
struct SrcList_item *pItem;
assert(pList || pParse->db->mallocFailed );
if( pList ){
for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
if( pItem->iCursor>=0 ) continue;
pItem->iCursor = pParse->nTab++;
if( pItem->pSelect ){
sqlite3SrcListAssignCursors(pParse, pItem->pSelect->pSrc);
}
}
}
}
/*
** Delete an entire SrcList including all its substructure.
*/
SQLITE_PRIVATE void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){
int i;
struct SrcList_item *pItem;
if( pList==0 ) return;
for(pItem=pList->a, i=0; i<pList->nSrc; i++, pItem++){
if( pItem->zDatabase ) sqlite3DbFreeNN(db, pItem->zDatabase);
sqlite3DbFree(db, pItem->zName);
if( pItem->zAlias ) sqlite3DbFreeNN(db, pItem->zAlias);
if( pItem->fg.isIndexedBy ) sqlite3DbFree(db, pItem->u1.zIndexedBy);
if( pItem->fg.isTabFunc ) sqlite3ExprListDelete(db, pItem->u1.pFuncArg);
sqlite3DeleteTable(db, pItem->pTab);
if( pItem->pSelect ) sqlite3SelectDelete(db, pItem->pSelect);
if( pItem->pOn ) sqlite3ExprDelete(db, pItem->pOn);
if( pItem->pUsing ) sqlite3IdListDelete(db, pItem->pUsing);
}
sqlite3DbFreeNN(db, pList);
}
/*
** This routine is called by the parser to add a new term to the
** end of a growing FROM clause. The "p" parameter is the part of
** the FROM clause that has already been constructed. "p" is NULL
** if this is the first term of the FROM clause. pTable and pDatabase
** are the name of the table and database named in the FROM clause term.
** pDatabase is NULL if the database name qualifier is missing - the
** usual case. If the term has an alias, then pAlias points to the
** alias token. If the term is a subquery, then pSubquery is the
** SELECT statement that the subquery encodes. The pTable and
** pDatabase parameters are NULL for subqueries. The pOn and pUsing
** parameters are the content of the ON and USING clauses.
**
** Return a new SrcList which encodes is the FROM with the new
** term added.
*/
SQLITE_PRIVATE SrcList *sqlite3SrcListAppendFromTerm(
Parse *pParse, /* Parsing context */
SrcList *p, /* The left part of the FROM clause already seen */
Token *pTable, /* Name of the table to add to the FROM clause */
Token *pDatabase, /* Name of the database containing pTable */
Token *pAlias, /* The right-hand side of the AS subexpression */
Select *pSubquery, /* A subquery used in place of a table name */
Expr *pOn, /* The ON clause of a join */
IdList *pUsing /* The USING clause of a join */
){
struct SrcList_item *pItem;
sqlite3 *db = pParse->db;
if( !p && (pOn || pUsing) ){
sqlite3ErrorMsg(pParse, "a JOIN clause is required before %s",
(pOn ? "ON" : "USING")
);
goto append_from_error;
}
p = sqlite3SrcListAppend(pParse, p, pTable, pDatabase);
if( p==0 ){
goto append_from_error;
}
assert( p->nSrc>0 );
pItem = &p->a[p->nSrc-1];
assert( (pTable==0)==(pDatabase==0) );
assert( pItem->zName==0 || pDatabase!=0 );
if( IN_RENAME_OBJECT && pItem->zName ){
Token *pToken = (ALWAYS(pDatabase) && pDatabase->z) ? pDatabase : pTable;
sqlite3RenameTokenMap(pParse, pItem->zName, pToken);
}
assert( pAlias!=0 );
if( pAlias->n ){
pItem->zAlias = sqlite3NameFromToken(db, pAlias);
}
pItem->pSelect = pSubquery;
pItem->pOn = pOn;
pItem->pUsing = pUsing;
return p;
append_from_error:
assert( p==0 );
sqlite3ExprDelete(db, pOn);
sqlite3IdListDelete(db, pUsing);
sqlite3SelectDelete(db, pSubquery);
return 0;
}
/*
** Add an INDEXED BY or NOT INDEXED clause to the most recently added
** element of the source-list passed as the second argument.
*/
SQLITE_PRIVATE void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pIndexedBy){
assert( pIndexedBy!=0 );
if( p && pIndexedBy->n>0 ){
struct SrcList_item *pItem;
assert( p->nSrc>0 );
pItem = &p->a[p->nSrc-1];
assert( pItem->fg.notIndexed==0 );
assert( pItem->fg.isIndexedBy==0 );
assert( pItem->fg.isTabFunc==0 );
if( pIndexedBy->n==1 && !pIndexedBy->z ){
/* A "NOT INDEXED" clause was supplied. See parse.y
** construct "indexed_opt" for details. */
pItem->fg.notIndexed = 1;
}else{
pItem->u1.zIndexedBy = sqlite3NameFromToken(pParse->db, pIndexedBy);
pItem->fg.isIndexedBy = 1;
}
}
}
/*
** Append the contents of SrcList p2 to SrcList p1 and return the resulting
** SrcList. Or, if an error occurs, return NULL. In all cases, p1 and p2
** are deleted by this function.
*/
SQLITE_PRIVATE SrcList *sqlite3SrcListAppendList(Parse *pParse, SrcList *p1, SrcList *p2){
assert( p1 && p1->nSrc==1 );
if( p2 ){
SrcList *pNew = sqlite3SrcListEnlarge(pParse, p1, p2->nSrc, 1);
if( pNew==0 ){
sqlite3SrcListDelete(pParse->db, p2);
}else{
p1 = pNew;
memcpy(&p1->a[1], p2->a, p2->nSrc*sizeof(struct SrcList_item));
sqlite3DbFree(pParse->db, p2);
}
}
return p1;
}
/*
** Add the list of function arguments to the SrcList entry for a
** table-valued-function.
*/
SQLITE_PRIVATE void sqlite3SrcListFuncArgs(Parse *pParse, SrcList *p, ExprList *pList){
if( p ){
struct SrcList_item *pItem = &p->a[p->nSrc-1];
assert( pItem->fg.notIndexed==0 );
assert( pItem->fg.isIndexedBy==0 );
assert( pItem->fg.isTabFunc==0 );
pItem->u1.pFuncArg = pList;
pItem->fg.isTabFunc = 1;
}else{
sqlite3ExprListDelete(pParse->db, pList);
}
}
/*
** When building up a FROM clause in the parser, the join operator
** is initially attached to the left operand. But the code generator
** expects the join operator to be on the right operand. This routine
** Shifts all join operators from left to right for an entire FROM
** clause.
**
** Example: Suppose the join is like this:
**
** A natural cross join B
**
** The operator is "natural cross join". The A and B operands are stored
** in p->a[0] and p->a[1], respectively. The parser initially stores the
** operator with A. This routine shifts that operator over to B.
*/
SQLITE_PRIVATE void sqlite3SrcListShiftJoinType(SrcList *p){
if( p ){
int i;
for(i=p->nSrc-1; i>0; i--){
p->a[i].fg.jointype = p->a[i-1].fg.jointype;
}
p->a[0].fg.jointype = 0;
}
}
/*
** Generate VDBE code for a BEGIN statement.
*/
SQLITE_PRIVATE void sqlite3BeginTransaction(Parse *pParse, int type){
sqlite3 *db;
Vdbe *v;
int i;
assert( pParse!=0 );
db = pParse->db;
assert( db!=0 );
if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ){
return;
}
v = sqlite3GetVdbe(pParse);
if( !v ) return;
if( type!=TK_DEFERRED ){
for(i=0; i<db->nDb; i++){
int eTxnType;
Btree *pBt = db->aDb[i].pBt;
if( pBt && sqlite3BtreeIsReadonly(pBt) ){
eTxnType = 0; /* Read txn */
}else if( type==TK_EXCLUSIVE ){
eTxnType = 2; /* Exclusive txn */
}else{
eTxnType = 1; /* Write txn */
}
sqlite3VdbeAddOp2(v, OP_Transaction, i, eTxnType);
sqlite3VdbeUsesBtree(v, i);
}
}
sqlite3VdbeAddOp0(v, OP_AutoCommit);
}
/*
** Generate VDBE code for a COMMIT or ROLLBACK statement.
** Code for ROLLBACK is generated if eType==TK_ROLLBACK. Otherwise
** code is generated for a COMMIT.
*/
SQLITE_PRIVATE void sqlite3EndTransaction(Parse *pParse, int eType){
Vdbe *v;
int isRollback;
assert( pParse!=0 );
assert( pParse->db!=0 );
assert( eType==TK_COMMIT || eType==TK_END || eType==TK_ROLLBACK );
isRollback = eType==TK_ROLLBACK;
if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION,
isRollback ? "ROLLBACK" : "COMMIT", 0, 0) ){
return;
}
v = sqlite3GetVdbe(pParse);
if( v ){
sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, isRollback);
}
}
/*
** This function is called by the parser when it parses a command to create,
** release or rollback an SQL savepoint.
*/
SQLITE_PRIVATE void sqlite3Savepoint(Parse *pParse, int op, Token *pName){
char *zName = sqlite3NameFromToken(pParse->db, pName);
if( zName ){
Vdbe *v = sqlite3GetVdbe(pParse);
#ifndef SQLITE_OMIT_AUTHORIZATION
static const char * const az[] = { "BEGIN", "RELEASE", "ROLLBACK" };
assert( !SAVEPOINT_BEGIN && SAVEPOINT_RELEASE==1 && SAVEPOINT_ROLLBACK==2 );
#endif
if( !v || sqlite3AuthCheck(pParse, SQLITE_SAVEPOINT, az[op], zName, 0) ){
sqlite3DbFree(pParse->db, zName);
return;
}
sqlite3VdbeAddOp4(v, OP_Savepoint, op, 0, 0, zName, P4_DYNAMIC);
}
}
/*
** Make sure the TEMP database is open and available for use. Return
** the number of errors. Leave any error messages in the pParse structure.
*/
SQLITE_PRIVATE int sqlite3OpenTempDatabase(Parse *pParse){
sqlite3 *db = pParse->db;
if( db->aDb[1].pBt==0 && !pParse->explain ){
int rc;
Btree *pBt;
static const int flags =
SQLITE_OPEN_READWRITE |
SQLITE_OPEN_CREATE |
SQLITE_OPEN_EXCLUSIVE |
SQLITE_OPEN_DELETEONCLOSE |
SQLITE_OPEN_TEMP_DB;
rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pBt, 0, flags);
if( rc!=SQLITE_OK ){
sqlite3ErrorMsg(pParse, "unable to open a temporary database "
"file for storing temporary tables");
pParse->rc = rc;
return 1;
}
db->aDb[1].pBt = pBt;
assert( db->aDb[1].pSchema );
if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, 0, 0) ){
sqlite3OomFault(db);
return 1;
}
}
return 0;
}
/*
** Record the fact that the schema cookie will need to be verified
** for database iDb. The code to actually verify the schema cookie
** will occur at the end of the top-level VDBE and will be generated
** later, by sqlite3FinishCoding().
*/
static void sqlite3CodeVerifySchemaAtToplevel(Parse *pToplevel, int iDb){
assert( iDb>=0 && iDb<pToplevel->db->nDb );
assert( pToplevel->db->aDb[iDb].pBt!=0 || iDb==1 );
assert( iDb<SQLITE_MAX_ATTACHED+2 );
assert( sqlite3SchemaMutexHeld(pToplevel->db, iDb, 0) );
if( DbMaskTest(pToplevel->cookieMask, iDb)==0 ){
DbMaskSet(pToplevel->cookieMask, iDb);
if( !OMIT_TEMPDB && iDb==1 ){
sqlite3OpenTempDatabase(pToplevel);
}
}
}
SQLITE_PRIVATE void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
sqlite3CodeVerifySchemaAtToplevel(sqlite3ParseToplevel(pParse), iDb);
}
/*
** If argument zDb is NULL, then call sqlite3CodeVerifySchema() for each
** attached database. Otherwise, invoke it for the database named zDb only.
*/
SQLITE_PRIVATE void sqlite3CodeVerifyNamedSchema(Parse *pParse, const char *zDb){
sqlite3 *db = pParse->db;
int i;
for(i=0; i<db->nDb; i++){
Db *pDb = &db->aDb[i];
if( pDb->pBt && (!zDb || 0==sqlite3StrICmp(zDb, pDb->zDbSName)) ){
sqlite3CodeVerifySchema(pParse, i);
}
}
}
/*
** Generate VDBE code that prepares for doing an operation that
** might change the database.
**
** This routine starts a new transaction if we are not already within
** a transaction. If we are already within a transaction, then a checkpoint
** is set if the setStatement parameter is true. A checkpoint should
** be set for operations that might fail (due to a constraint) part of
** the way through and which will need to undo some writes without having to
** rollback the whole transaction. For operations where all constraints
** can be checked before any changes are made to the database, it is never
** necessary to undo a write and the checkpoint should not be set.
*/
SQLITE_PRIVATE void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
Parse *pToplevel = sqlite3ParseToplevel(pParse);
sqlite3CodeVerifySchemaAtToplevel(pToplevel, iDb);
DbMaskSet(pToplevel->writeMask, iDb);
pToplevel->isMultiWrite |= setStatement;
}
/*
** Indicate that the statement currently under construction might write
** more than one entry (example: deleting one row then inserting another,
** inserting multiple rows in a table, or inserting a row and index entries.)
** If an abort occurs after some of these writes have completed, then it will
** be necessary to undo the completed writes.
*/
SQLITE_PRIVATE void sqlite3MultiWrite(Parse *pParse){
Parse *pToplevel = sqlite3ParseToplevel(pParse);
pToplevel->isMultiWrite = 1;
}
/*
** The code generator calls this routine if is discovers that it is
** possible to abort a statement prior to completion. In order to
** perform this abort without corrupting the database, we need to make
** sure that the statement is protected by a statement transaction.
**
** Technically, we only need to set the mayAbort flag if the
** isMultiWrite flag was previously set. There is a time dependency
** such that the abort must occur after the multiwrite. This makes
** some statements involving the REPLACE conflict resolution algorithm
** go a little faster. But taking advantage of this time dependency
** makes it more difficult to prove that the code is correct (in
** particular, it prevents us from writing an effective
** implementation of sqlite3AssertMayAbort()) and so we have chosen
** to take the safe route and skip the optimization.
*/
SQLITE_PRIVATE void sqlite3MayAbort(Parse *pParse){
Parse *pToplevel = sqlite3ParseToplevel(pParse);
pToplevel->mayAbort = 1;
}
/*
** Code an OP_Halt that causes the vdbe to return an SQLITE_CONSTRAINT
** error. The onError parameter determines which (if any) of the statement
** and/or current transaction is rolled back.
*/
SQLITE_PRIVATE void sqlite3HaltConstraint(
Parse *pParse, /* Parsing context */
int errCode, /* extended error code */
int onError, /* Constraint type */
char *p4, /* Error message */
i8 p4type, /* P4_STATIC or P4_TRANSIENT */
u8 p5Errmsg /* P5_ErrMsg type */
){
Vdbe *v;
assert( pParse->pVdbe!=0 );
v = sqlite3GetVdbe(pParse);
assert( (errCode&0xff)==SQLITE_CONSTRAINT || pParse->nested );
if( onError==OE_Abort ){
sqlite3MayAbort(pParse);
}
sqlite3VdbeAddOp4(v, OP_Halt, errCode, onError, 0, p4, p4type);
sqlite3VdbeChangeP5(v, p5Errmsg);
}
/*
** Code an OP_Halt due to UNIQUE or PRIMARY KEY constraint violation.
*/
SQLITE_PRIVATE void sqlite3UniqueConstraint(
Parse *pParse, /* Parsing context */
int onError, /* Constraint type */
Index *pIdx /* The index that triggers the constraint */
){
char *zErr;
int j;
StrAccum errMsg;
Table *pTab = pIdx->pTable;
sqlite3StrAccumInit(&errMsg, pParse->db, 0, 0,
pParse->db->aLimit[SQLITE_LIMIT_LENGTH]);
if( pIdx->aColExpr ){
sqlite3_str_appendf(&errMsg, "index '%q'", pIdx->zName);
}else{
for(j=0; j<pIdx->nKeyCol; j++){
char *zCol;
assert( pIdx->aiColumn[j]>=0 );
zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
if( j ) sqlite3_str_append(&errMsg, ", ", 2);
sqlite3_str_appendall(&errMsg, pTab->zName);
sqlite3_str_append(&errMsg, ".", 1);
sqlite3_str_appendall(&errMsg, zCol);
}
}
zErr = sqlite3StrAccumFinish(&errMsg);
sqlite3HaltConstraint(pParse,
IsPrimaryKeyIndex(pIdx) ? SQLITE_CONSTRAINT_PRIMARYKEY
: SQLITE_CONSTRAINT_UNIQUE,
onError, zErr, P4_DYNAMIC, P5_ConstraintUnique);
}
/*
** Code an OP_Halt due to non-unique rowid.
*/
SQLITE_PRIVATE void sqlite3RowidConstraint(
Parse *pParse, /* Parsing context */
int onError, /* Conflict resolution algorithm */
Table *pTab /* The table with the non-unique rowid */
){
char *zMsg;
int rc;
if( pTab->iPKey>=0 ){
zMsg = sqlite3MPrintf(pParse->db, "%s.%s", pTab->zName,
pTab->aCol[pTab->iPKey].zName);
rc = SQLITE_CONSTRAINT_PRIMARYKEY;
}else{
zMsg = sqlite3MPrintf(pParse->db, "%s.rowid", pTab->zName);
rc = SQLITE_CONSTRAINT_ROWID;
}
sqlite3HaltConstraint(pParse, rc, onError, zMsg, P4_DYNAMIC,
P5_ConstraintUnique);
}
/*
** Check to see if pIndex uses the collating sequence pColl. Return
** true if it does and false if it does not.
*/
#ifndef SQLITE_OMIT_REINDEX
static int collationMatch(const char *zColl, Index *pIndex){
int i;
assert( zColl!=0 );
for(i=0; i<pIndex->nColumn; i++){
const char *z = pIndex->azColl[i];
assert( z!=0 || pIndex->aiColumn[i]<0 );
if( pIndex->aiColumn[i]>=0 && 0==sqlite3StrICmp(z, zColl) ){
return 1;
}
}
return 0;
}
#endif
/*
** Recompute all indices of pTab that use the collating sequence pColl.
** If pColl==0 then recompute all indices of pTab.
*/
#ifndef SQLITE_OMIT_REINDEX
static void reindexTable(Parse *pParse, Table *pTab, char const *zColl){
if( !IsVirtual(pTab) ){
Index *pIndex; /* An index associated with pTab */
for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
if( zColl==0 || collationMatch(zColl, pIndex) ){
int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3RefillIndex(pParse, pIndex, -1);
}
}
}
}
#endif
/*
** Recompute all indices of all tables in all databases where the
** indices use the collating sequence pColl. If pColl==0 then recompute
** all indices everywhere.
*/
#ifndef SQLITE_OMIT_REINDEX
static void reindexDatabases(Parse *pParse, char const *zColl){
Db *pDb; /* A single database */
int iDb; /* The database index number */
sqlite3 *db = pParse->db; /* The database connection */
HashElem *k; /* For looping over tables in pDb */
Table *pTab; /* A table in the database */
assert( sqlite3BtreeHoldsAllMutexes(db) ); /* Needed for schema access */
for(iDb=0, pDb=db->aDb; iDb<db->nDb; iDb++, pDb++){
assert( pDb!=0 );
for(k=sqliteHashFirst(&pDb->pSchema->tblHash); k; k=sqliteHashNext(k)){
pTab = (Table*)sqliteHashData(k);
reindexTable(pParse, pTab, zColl);
}
}
}
#endif
/*
** Generate code for the REINDEX command.
**
** REINDEX -- 1
** REINDEX <collation> -- 2
** REINDEX ?<database>.?<tablename> -- 3
** REINDEX ?<database>.?<indexname> -- 4
**
** Form 1 causes all indices in all attached databases to be rebuilt.
** Form 2 rebuilds all indices in all databases that use the named
** collating function. Forms 3 and 4 rebuild the named index or all
** indices associated with the named table.
*/
#ifndef SQLITE_OMIT_REINDEX
SQLITE_PRIVATE void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){
CollSeq *pColl; /* Collating sequence to be reindexed, or NULL */
char *z; /* Name of a table or index */
const char *zDb; /* Name of the database */
Table *pTab; /* A table in the database */
Index *pIndex; /* An index associated with pTab */
int iDb; /* The database index number */
sqlite3 *db = pParse->db; /* The database connection */
Token *pObjName; /* Name of the table or index to be reindexed */
/* Read the database schema. If an error occurs, leave an error message
** and code in pParse and return NULL. */
if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
return;
}
if( pName1==0 ){
reindexDatabases(pParse, 0);
return;
}else if( NEVER(pName2==0) || pName2->z==0 ){
char *zColl;
assert( pName1->z );
zColl = sqlite3NameFromToken(pParse->db, pName1);
if( !zColl ) return;
pColl = sqlite3FindCollSeq(db, ENC(db), zColl, 0);
if( pColl ){
reindexDatabases(pParse, zColl);
sqlite3DbFree(db, zColl);
return;
}
sqlite3DbFree(db, zColl);
}
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pObjName);
if( iDb<0 ) return;
z = sqlite3NameFromToken(db, pObjName);
if( z==0 ) return;
zDb = db->aDb[iDb].zDbSName;
pTab = sqlite3FindTable(db, z, zDb);
if( pTab ){
reindexTable(pParse, pTab, 0);
sqlite3DbFree(db, z);
return;
}
pIndex = sqlite3FindIndex(db, z, zDb);
sqlite3DbFree(db, z);
if( pIndex ){
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3RefillIndex(pParse, pIndex, -1);
return;
}
sqlite3ErrorMsg(pParse, "unable to identify the object to be reindexed");
}
#endif
/*
** Return a KeyInfo structure that is appropriate for the given Index.
**
** The caller should invoke sqlite3KeyInfoUnref() on the returned object
** when it has finished using it.
*/
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoOfIndex(Parse *pParse, Index *pIdx){
int i;
int nCol = pIdx->nColumn;
int nKey = pIdx->nKeyCol;
KeyInfo *pKey;
if( pParse->nErr ) return 0;
if( pIdx->uniqNotNull ){
pKey = sqlite3KeyInfoAlloc(pParse->db, nKey, nCol-nKey);
}else{
pKey = sqlite3KeyInfoAlloc(pParse->db, nCol, 0);
}
if( pKey ){
assert( sqlite3KeyInfoIsWriteable(pKey) );
for(i=0; i<nCol; i++){
const char *zColl = pIdx->azColl[i];
pKey->aColl[i] = zColl==sqlite3StrBINARY ? 0 :
sqlite3LocateCollSeq(pParse, zColl);
pKey->aSortFlags[i] = pIdx->aSortOrder[i];
assert( 0==(pKey->aSortFlags[i] & KEYINFO_ORDER_BIGNULL) );
}
if( pParse->nErr ){
assert( pParse->rc==SQLITE_ERROR_MISSING_COLLSEQ );
if( pIdx->bNoQuery==0 ){
/* Deactivate the index because it contains an unknown collating
** sequence. The only way to reactive the index is to reload the
** schema. Adding the missing collating sequence later does not
** reactive the index. The application had the chance to register
** the missing index using the collation-needed callback. For
** simplicity, SQLite will not give the application a second chance.
*/
pIdx->bNoQuery = 1;
pParse->rc = SQLITE_ERROR_RETRY;
}
sqlite3KeyInfoUnref(pKey);
pKey = 0;
}
}
return pKey;
}
#ifndef SQLITE_OMIT_CTE
/*
** This routine is invoked once per CTE by the parser while parsing a
** WITH clause.
*/
SQLITE_PRIVATE With *sqlite3WithAdd(
Parse *pParse, /* Parsing context */
With *pWith, /* Existing WITH clause, or NULL */
Token *pName, /* Name of the common-table */
ExprList *pArglist, /* Optional column name list for the table */
Select *pQuery /* Query used to initialize the table */
){
sqlite3 *db = pParse->db;
With *pNew;
char *zName;
/* Check that the CTE name is unique within this WITH clause. If
** not, store an error in the Parse structure. */
zName = sqlite3NameFromToken(pParse->db, pName);
if( zName && pWith ){
int i;
for(i=0; i<pWith->nCte; i++){
if( sqlite3StrICmp(zName, pWith->a[i].zName)==0 ){
sqlite3ErrorMsg(pParse, "duplicate WITH table name: %s", zName);
}
}
}
if( pWith ){
sqlite3_int64 nByte = sizeof(*pWith) + (sizeof(pWith->a[1]) * pWith->nCte);
pNew = sqlite3DbRealloc(db, pWith, nByte);
}else{
pNew = sqlite3DbMallocZero(db, sizeof(*pWith));
}
assert( (pNew!=0 && zName!=0) || db->mallocFailed );
if( db->mallocFailed ){
sqlite3ExprListDelete(db, pArglist);
sqlite3SelectDelete(db, pQuery);
sqlite3DbFree(db, zName);
pNew = pWith;
}else{
pNew->a[pNew->nCte].pSelect = pQuery;
pNew->a[pNew->nCte].pCols = pArglist;
pNew->a[pNew->nCte].zName = zName;
pNew->a[pNew->nCte].zCteErr = 0;
pNew->nCte++;
}
return pNew;
}
/*
** Free the contents of the With object passed as the second argument.
*/
SQLITE_PRIVATE void sqlite3WithDelete(sqlite3 *db, With *pWith){
if( pWith ){
int i;
for(i=0; i<pWith->nCte; i++){
struct Cte *pCte = &pWith->a[i];
sqlite3ExprListDelete(db, pCte->pCols);
sqlite3SelectDelete(db, pCte->pSelect);
sqlite3DbFree(db, pCte->zName);
}
sqlite3DbFree(db, pWith);
}
}
#endif /* !defined(SQLITE_OMIT_CTE) */
/************** End of build.c ***********************************************/
/************** Begin file callback.c ****************************************/
/*
** 2005 May 23
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains functions used to access the internal hash tables
** of user defined functions and collation sequences.
*/
/* #include "sqliteInt.h" */
/*
** Invoke the 'collation needed' callback to request a collation sequence
** in the encoding enc of name zName, length nName.
*/
static void callCollNeeded(sqlite3 *db, int enc, const char *zName){
assert( !db->xCollNeeded || !db->xCollNeeded16 );
if( db->xCollNeeded ){
char *zExternal = sqlite3DbStrDup(db, zName);
if( !zExternal ) return;
db->xCollNeeded(db->pCollNeededArg, db, enc, zExternal);
sqlite3DbFree(db, zExternal);
}
#ifndef SQLITE_OMIT_UTF16
if( db->xCollNeeded16 ){
char const *zExternal;
sqlite3_value *pTmp = sqlite3ValueNew(db);
sqlite3ValueSetStr(pTmp, -1, zName, SQLITE_UTF8, SQLITE_STATIC);
zExternal = sqlite3ValueText(pTmp, SQLITE_UTF16NATIVE);
if( zExternal ){
db->xCollNeeded16(db->pCollNeededArg, db, (int)ENC(db), zExternal);
}
sqlite3ValueFree(pTmp);
}
#endif
}
/*
** This routine is called if the collation factory fails to deliver a
** collation function in the best encoding but there may be other versions
** of this collation function (for other text encodings) available. Use one
** of these instead if they exist. Avoid a UTF-8 <-> UTF-16 conversion if
** possible.
*/
static int synthCollSeq(sqlite3 *db, CollSeq *pColl){
CollSeq *pColl2;
char *z = pColl->zName;
int i;
static const u8 aEnc[] = { SQLITE_UTF16BE, SQLITE_UTF16LE, SQLITE_UTF8 };
for(i=0; i<3; i++){
pColl2 = sqlite3FindCollSeq(db, aEnc[i], z, 0);
if( pColl2->xCmp!=0 ){
memcpy(pColl, pColl2, sizeof(CollSeq));
pColl->xDel = 0; /* Do not copy the destructor */
return SQLITE_OK;
}
}
return SQLITE_ERROR;
}
/*
** This routine is called on a collation sequence before it is used to
** check that it is defined. An undefined collation sequence exists when
** a database is loaded that contains references to collation sequences
** that have not been defined by sqlite3_create_collation() etc.
**
** If required, this routine calls the 'collation needed' callback to
** request a definition of the collating sequence. If this doesn't work,
** an equivalent collating sequence that uses a text encoding different
** from the main database is substituted, if one is available.
*/
SQLITE_PRIVATE int sqlite3CheckCollSeq(Parse *pParse, CollSeq *pColl){
if( pColl && pColl->xCmp==0 ){
const char *zName = pColl->zName;
sqlite3 *db = pParse->db;
CollSeq *p = sqlite3GetCollSeq(pParse, ENC(db), pColl, zName);
if( !p ){
return SQLITE_ERROR;
}
assert( p==pColl );
}
return SQLITE_OK;
}
/*
** Locate and return an entry from the db.aCollSeq hash table. If the entry
** specified by zName and nName is not found and parameter 'create' is
** true, then create a new entry. Otherwise return NULL.
**
** Each pointer stored in the sqlite3.aCollSeq hash table contains an
** array of three CollSeq structures. The first is the collation sequence
** preferred for UTF-8, the second UTF-16le, and the third UTF-16be.
**
** Stored immediately after the three collation sequences is a copy of
** the collation sequence name. A pointer to this string is stored in
** each collation sequence structure.
*/
static CollSeq *findCollSeqEntry(
sqlite3 *db, /* Database connection */
const char *zName, /* Name of the collating sequence */
int create /* Create a new entry if true */
){
CollSeq *pColl;
pColl = sqlite3HashFind(&db->aCollSeq, zName);
if( 0==pColl && create ){
int nName = sqlite3Strlen30(zName) + 1;
pColl = sqlite3DbMallocZero(db, 3*sizeof(*pColl) + nName);
if( pColl ){
CollSeq *pDel = 0;
pColl[0].zName = (char*)&pColl[3];
pColl[0].enc = SQLITE_UTF8;
pColl[1].zName = (char*)&pColl[3];
pColl[1].enc = SQLITE_UTF16LE;
pColl[2].zName = (char*)&pColl[3];
pColl[2].enc = SQLITE_UTF16BE;
memcpy(pColl[0].zName, zName, nName);
pDel = sqlite3HashInsert(&db->aCollSeq, pColl[0].zName, pColl);
/* If a malloc() failure occurred in sqlite3HashInsert(), it will
** return the pColl pointer to be deleted (because it wasn't added
** to the hash table).
*/
assert( pDel==0 || pDel==pColl );
if( pDel!=0 ){
sqlite3OomFault(db);
sqlite3DbFree(db, pDel);
pColl = 0;
}
}
}
return pColl;
}
/*
** Parameter zName points to a UTF-8 encoded string nName bytes long.
** Return the CollSeq* pointer for the collation sequence named zName
** for the encoding 'enc' from the database 'db'.
**
** If the entry specified is not found and 'create' is true, then create a
** new entry. Otherwise return NULL.
**
** A separate function sqlite3LocateCollSeq() is a wrapper around
** this routine. sqlite3LocateCollSeq() invokes the collation factory
** if necessary and generates an error message if the collating sequence
** cannot be found.
**
** See also: sqlite3LocateCollSeq(), sqlite3GetCollSeq()
*/
SQLITE_PRIVATE CollSeq *sqlite3FindCollSeq(
sqlite3 *db, /* Database connection to search */
u8 enc, /* Desired text encoding */
const char *zName, /* Name of the collating sequence. Might be NULL */
int create /* True to create CollSeq if doesn't already exist */
){
CollSeq *pColl;
assert( SQLITE_UTF8==1 && SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
assert( enc>=SQLITE_UTF8 && enc<=SQLITE_UTF16BE );
if( zName ){
pColl = findCollSeqEntry(db, zName, create);
if( pColl ) pColl += enc-1;
}else{
pColl = db->pDfltColl;
}
return pColl;
}
/*
** Change the text encoding for a database connection. This means that
** the pDfltColl must change as well.
*/
SQLITE_PRIVATE void sqlite3SetTextEncoding(sqlite3 *db, u8 enc){
assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
db->enc = enc;
/* EVIDENCE-OF: R-08308-17224 The default collating function for all
** strings is BINARY.
*/
db->pDfltColl = sqlite3FindCollSeq(db, enc, sqlite3StrBINARY, 0);
}
/*
** This function is responsible for invoking the collation factory callback
** or substituting a collation sequence of a different encoding when the
** requested collation sequence is not available in the desired encoding.
**
** If it is not NULL, then pColl must point to the database native encoding
** collation sequence with name zName, length nName.
**
** The return value is either the collation sequence to be used in database
** db for collation type name zName, length nName, or NULL, if no collation
** sequence can be found. If no collation is found, leave an error message.
**
** See also: sqlite3LocateCollSeq(), sqlite3FindCollSeq()
*/
SQLITE_PRIVATE CollSeq *sqlite3GetCollSeq(
Parse *pParse, /* Parsing context */
u8 enc, /* The desired encoding for the collating sequence */
CollSeq *pColl, /* Collating sequence with native encoding, or NULL */
const char *zName /* Collating sequence name */
){
CollSeq *p;
sqlite3 *db = pParse->db;
p = pColl;
if( !p ){
p = sqlite3FindCollSeq(db, enc, zName, 0);
}
if( !p || !p->xCmp ){
/* No collation sequence of this type for this encoding is registered.
** Call the collation factory to see if it can supply us with one.
*/
callCollNeeded(db, enc, zName);
p = sqlite3FindCollSeq(db, enc, zName, 0);
}
if( p && !p->xCmp && synthCollSeq(db, p) ){
p = 0;
}
assert( !p || p->xCmp );
if( p==0 ){
sqlite3ErrorMsg(pParse, "no such collation sequence: %s", zName);
pParse->rc = SQLITE_ERROR_MISSING_COLLSEQ;
}
return p;
}
/*
** This function returns the collation sequence for database native text
** encoding identified by the string zName.
**
** If the requested collation sequence is not available, or not available
** in the database native encoding, the collation factory is invoked to
** request it. If the collation factory does not supply such a sequence,
** and the sequence is available in another text encoding, then that is
** returned instead.
**
** If no versions of the requested collations sequence are available, or
** another error occurs, NULL is returned and an error message written into
** pParse.
**
** This routine is a wrapper around sqlite3FindCollSeq(). This routine
** invokes the collation factory if the named collation cannot be found
** and generates an error message.
**
** See also: sqlite3FindCollSeq(), sqlite3GetCollSeq()
*/
SQLITE_PRIVATE CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char *zName){
sqlite3 *db = pParse->db;
u8 enc = ENC(db);
u8 initbusy = db->init.busy;
CollSeq *pColl;
pColl = sqlite3FindCollSeq(db, enc, zName, initbusy);
if( !initbusy && (!pColl || !pColl->xCmp) ){
pColl = sqlite3GetCollSeq(pParse, enc, pColl, zName);
}
return pColl;
}
/* During the search for the best function definition, this procedure
** is called to test how well the function passed as the first argument
** matches the request for a function with nArg arguments in a system
** that uses encoding enc. The value returned indicates how well the
** request is matched. A higher value indicates a better match.
**
** If nArg is -1 that means to only return a match (non-zero) if p->nArg
** is also -1. In other words, we are searching for a function that
** takes a variable number of arguments.
**
** If nArg is -2 that means that we are searching for any function
** regardless of the number of arguments it uses, so return a positive
** match score for any
**
** The returned value is always between 0 and 6, as follows:
**
** 0: Not a match.
** 1: UTF8/16 conversion required and function takes any number of arguments.
** 2: UTF16 byte order change required and function takes any number of args.
** 3: encoding matches and function takes any number of arguments
** 4: UTF8/16 conversion required - argument count matches exactly
** 5: UTF16 byte order conversion required - argument count matches exactly
** 6: Perfect match: encoding and argument count match exactly.
**
** If nArg==(-2) then any function with a non-null xSFunc is
** a perfect match and any function with xSFunc NULL is
** a non-match.
*/
#define FUNC_PERFECT_MATCH 6 /* The score for a perfect match */
static int matchQuality(
FuncDef *p, /* The function we are evaluating for match quality */
int nArg, /* Desired number of arguments. (-1)==any */
u8 enc /* Desired text encoding */
){
int match;
assert( p->nArg>=-1 );
/* Wrong number of arguments means "no match" */
if( p->nArg!=nArg ){
if( nArg==(-2) ) return (p->xSFunc==0) ? 0 : FUNC_PERFECT_MATCH;
if( p->nArg>=0 ) return 0;
}
/* Give a better score to a function with a specific number of arguments
** than to function that accepts any number of arguments. */
if( p->nArg==nArg ){
match = 4;
}else{
match = 1;
}
/* Bonus points if the text encoding matches */
if( enc==(p->funcFlags & SQLITE_FUNC_ENCMASK) ){
match += 2; /* Exact encoding match */
}else if( (enc & p->funcFlags & 2)!=0 ){
match += 1; /* Both are UTF16, but with different byte orders */
}
return match;
}
/*
** Search a FuncDefHash for a function with the given name. Return
** a pointer to the matching FuncDef if found, or 0 if there is no match.
*/
SQLITE_PRIVATE FuncDef *sqlite3FunctionSearch(
int h, /* Hash of the name */
const char *zFunc /* Name of function */
){
FuncDef *p;
for(p=sqlite3BuiltinFunctions.a[h]; p; p=p->u.pHash){
if( sqlite3StrICmp(p->zName, zFunc)==0 ){
return p;
}
}
return 0;
}
/*
** Insert a new FuncDef into a FuncDefHash hash table.
*/
SQLITE_PRIVATE void sqlite3InsertBuiltinFuncs(
FuncDef *aDef, /* List of global functions to be inserted */
int nDef /* Length of the apDef[] list */
){
int i;
for(i=0; i<nDef; i++){
FuncDef *pOther;
const char *zName = aDef[i].zName;
int nName = sqlite3Strlen30(zName);
int h = SQLITE_FUNC_HASH(zName[0], nName);
assert( zName[0]>='a' && zName[0]<='z' );
pOther = sqlite3FunctionSearch(h, zName);
if( pOther ){
assert( pOther!=&aDef[i] && pOther->pNext!=&aDef[i] );
aDef[i].pNext = pOther->pNext;
pOther->pNext = &aDef[i];
}else{
aDef[i].pNext = 0;
aDef[i].u.pHash = sqlite3BuiltinFunctions.a[h];
sqlite3BuiltinFunctions.a[h] = &aDef[i];
}
}
}
/*
** Locate a user function given a name, a number of arguments and a flag
** indicating whether the function prefers UTF-16 over UTF-8. Return a
** pointer to the FuncDef structure that defines that function, or return
** NULL if the function does not exist.
**
** If the createFlag argument is true, then a new (blank) FuncDef
** structure is created and liked into the "db" structure if a
** no matching function previously existed.
**
** If nArg is -2, then the first valid function found is returned. A
** function is valid if xSFunc is non-zero. The nArg==(-2)
** case is used to see if zName is a valid function name for some number
** of arguments. If nArg is -2, then createFlag must be 0.
**
** If createFlag is false, then a function with the required name and
** number of arguments may be returned even if the eTextRep flag does not
** match that requested.
*/
SQLITE_PRIVATE FuncDef *sqlite3FindFunction(
sqlite3 *db, /* An open database */
const char *zName, /* Name of the function. zero-terminated */
int nArg, /* Number of arguments. -1 means any number */
u8 enc, /* Preferred text encoding */
u8 createFlag /* Create new entry if true and does not otherwise exist */
){
FuncDef *p; /* Iterator variable */
FuncDef *pBest = 0; /* Best match found so far */
int bestScore = 0; /* Score of best match */
int h; /* Hash value */
int nName; /* Length of the name */
assert( nArg>=(-2) );
assert( nArg>=(-1) || createFlag==0 );
nName = sqlite3Strlen30(zName);
/* First search for a match amongst the application-defined functions.
*/
p = (FuncDef*)sqlite3HashFind(&db->aFunc, zName);
while( p ){
int score = matchQuality(p, nArg, enc);
if( score>bestScore ){
pBest = p;
bestScore = score;
}
p = p->pNext;
}
/* If no match is found, search the built-in functions.
**
** If the DBFLAG_PreferBuiltin flag is set, then search the built-in
** functions even if a prior app-defined function was found. And give
** priority to built-in functions.
**
** Except, if createFlag is true, that means that we are trying to
** install a new function. Whatever FuncDef structure is returned it will
** have fields overwritten with new information appropriate for the
** new function. But the FuncDefs for built-in functions are read-only.
** So we must not search for built-ins when creating a new function.
*/
if( !createFlag && (pBest==0 || (db->mDbFlags & DBFLAG_PreferBuiltin)!=0) ){
bestScore = 0;
h = SQLITE_FUNC_HASH(sqlite3UpperToLower[(u8)zName[0]], nName);
p = sqlite3FunctionSearch(h, zName);
while( p ){
int score = matchQuality(p, nArg, enc);
if( score>bestScore ){
pBest = p;
bestScore = score;
}
p = p->pNext;
}
}
/* If the createFlag parameter is true and the search did not reveal an
** exact match for the name, number of arguments and encoding, then add a
** new entry to the hash table and return it.
*/
if( createFlag && bestScore<FUNC_PERFECT_MATCH &&
(pBest = sqlite3DbMallocZero(db, sizeof(*pBest)+nName+1))!=0 ){
FuncDef *pOther;
u8 *z;
pBest->zName = (const char*)&pBest[1];
pBest->nArg = (u16)nArg;
pBest->funcFlags = enc;
memcpy((char*)&pBest[1], zName, nName+1);
for(z=(u8*)pBest->zName; *z; z++) *z = sqlite3UpperToLower[*z];
pOther = (FuncDef*)sqlite3HashInsert(&db->aFunc, pBest->zName, pBest);
if( pOther==pBest ){
sqlite3DbFree(db, pBest);
sqlite3OomFault(db);
return 0;
}else{
pBest->pNext = pOther;
}
}
if( pBest && (pBest->xSFunc || createFlag) ){
return pBest;
}
return 0;
}
/*
** Free all resources held by the schema structure. The void* argument points
** at a Schema struct. This function does not call sqlite3DbFree(db, ) on the
** pointer itself, it just cleans up subsidiary resources (i.e. the contents
** of the schema hash tables).
**
** The Schema.cache_size variable is not cleared.
*/
SQLITE_PRIVATE void sqlite3SchemaClear(void *p){
Hash temp1;
Hash temp2;
HashElem *pElem;
Schema *pSchema = (Schema *)p;
temp1 = pSchema->tblHash;
temp2 = pSchema->trigHash;
sqlite3HashInit(&pSchema->trigHash);
sqlite3HashClear(&pSchema->idxHash);
for(pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
sqlite3DeleteTrigger(0, (Trigger*)sqliteHashData(pElem));
}
sqlite3HashClear(&temp2);
sqlite3HashInit(&pSchema->tblHash);
for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
Table *pTab = sqliteHashData(pElem);
sqlite3DeleteTable(0, pTab);
}
sqlite3HashClear(&temp1);
sqlite3HashClear(&pSchema->fkeyHash);
pSchema->pSeqTab = 0;
if( pSchema->schemaFlags & DB_SchemaLoaded ){
pSchema->iGeneration++;
}
pSchema->schemaFlags &= ~(DB_SchemaLoaded|DB_ResetWanted);
}
/*
** Find and return the schema associated with a BTree. Create
** a new one if necessary.
*/
SQLITE_PRIVATE Schema *sqlite3SchemaGet(sqlite3 *db, Btree *pBt){
Schema * p;
if( pBt ){
p = (Schema *)sqlite3BtreeSchema(pBt, sizeof(Schema), sqlite3SchemaClear);
}else{
p = (Schema *)sqlite3DbMallocZero(0, sizeof(Schema));
}
if( !p ){
sqlite3OomFault(db);
}else if ( 0==p->file_format ){
sqlite3HashInit(&p->tblHash);
sqlite3HashInit(&p->idxHash);
sqlite3HashInit(&p->trigHash);
sqlite3HashInit(&p->fkeyHash);
p->enc = SQLITE_UTF8;
}
return p;
}
/************** End of callback.c ********************************************/
/************** Begin file delete.c ******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
*/
/* #include "sqliteInt.h" */
/*
** While a SrcList can in general represent multiple tables and subqueries
** (as in the FROM clause of a SELECT statement) in this case it contains
** the name of a single table, as one might find in an INSERT, DELETE,
** or UPDATE statement. Look up that table in the symbol table and
** return a pointer. Set an error message and return NULL if the table
** name is not found or if any other error occurs.
**
** The following fields are initialized appropriate in pSrc:
**
** pSrc->a[0].pTab Pointer to the Table object
** pSrc->a[0].pIndex Pointer to the INDEXED BY index, if there is one
**
*/
SQLITE_PRIVATE Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
struct SrcList_item *pItem = pSrc->a;
Table *pTab;
assert( pItem && pSrc->nSrc>=1 );
pTab = sqlite3LocateTableItem(pParse, 0, pItem);
sqlite3DeleteTable(pParse->db, pItem->pTab);
pItem->pTab = pTab;
if( pTab ){
pTab->nTabRef++;
}
if( sqlite3IndexedByLookup(pParse, pItem) ){
pTab = 0;
}
return pTab;
}
/* Return true if table pTab is read-only.
**
** A table is read-only if any of the following are true:
**
** 1) It is a virtual table and no implementation of the xUpdate method
** has been provided
**
** 2) It is a system table (i.e. sqlite_schema), this call is not
** part of a nested parse and writable_schema pragma has not
** been specified
**
** 3) The table is a shadow table, the database connection is in
** defensive mode, and the current sqlite3_prepare()
** is for a top-level SQL statement.
*/
static int tabIsReadOnly(Parse *pParse, Table *pTab){
sqlite3 *db;
if( IsVirtual(pTab) ){
return sqlite3GetVTable(pParse->db, pTab)->pMod->pModule->xUpdate==0;
}
if( (pTab->tabFlags & (TF_Readonly|TF_Shadow))==0 ) return 0;
db = pParse->db;
if( (pTab->tabFlags & TF_Readonly)!=0 ){
return sqlite3WritableSchema(db)==0 && pParse->nested==0;
}
assert( pTab->tabFlags & TF_Shadow );
return sqlite3ReadOnlyShadowTables(db);
}
/*
** Check to make sure the given table is writable. If it is not
** writable, generate an error message and return 1. If it is
** writable return 0;
*/
SQLITE_PRIVATE int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
if( tabIsReadOnly(pParse, pTab) ){
sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
return 1;
}
#ifndef SQLITE_OMIT_VIEW
if( !viewOk && pTab->pSelect ){
sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
return 1;
}
#endif
return 0;
}
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
/*
** Evaluate a view and store its result in an ephemeral table. The
** pWhere argument is an optional WHERE clause that restricts the
** set of rows in the view that are to be added to the ephemeral table.
*/
SQLITE_PRIVATE void sqlite3MaterializeView(
Parse *pParse, /* Parsing context */
Table *pView, /* View definition */
Expr *pWhere, /* Optional WHERE clause to be added */
ExprList *pOrderBy, /* Optional ORDER BY clause */
Expr *pLimit, /* Optional LIMIT clause */
int iCur /* Cursor number for ephemeral table */
){
SelectDest dest;
Select *pSel;
SrcList *pFrom;
sqlite3 *db = pParse->db;
int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
pWhere = sqlite3ExprDup(db, pWhere, 0);
pFrom = sqlite3SrcListAppend(pParse, 0, 0, 0);
if( pFrom ){
assert( pFrom->nSrc==1 );
pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
assert( pFrom->a[0].pOn==0 );
assert( pFrom->a[0].pUsing==0 );
}
pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, pOrderBy,
SF_IncludeHidden, pLimit);
sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
sqlite3Select(pParse, pSel, &dest);
sqlite3SelectDelete(db, pSel);
}
#endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
/*
** Generate an expression tree to implement the WHERE, ORDER BY,
** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
**
** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
** \__________________________/
** pLimitWhere (pInClause)
*/
SQLITE_PRIVATE Expr *sqlite3LimitWhere(
Parse *pParse, /* The parser context */
SrcList *pSrc, /* the FROM clause -- which tables to scan */
Expr *pWhere, /* The WHERE clause. May be null */
ExprList *pOrderBy, /* The ORDER BY clause. May be null */
Expr *pLimit, /* The LIMIT clause. May be null */
char *zStmtType /* Either DELETE or UPDATE. For err msgs. */
){
sqlite3 *db = pParse->db;
Expr *pLhs = NULL; /* LHS of IN(SELECT...) operator */
Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */
SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */
Select *pSelect = NULL; /* Complete SELECT tree */
Table *pTab;
/* Check that there isn't an ORDER BY without a LIMIT clause.
*/
if( pOrderBy && pLimit==0 ) {
sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
sqlite3ExprDelete(pParse->db, pWhere);
sqlite3ExprListDelete(pParse->db, pOrderBy);
return 0;
}
/* We only need to generate a select expression if there
** is a limit/offset term to enforce.
*/
if( pLimit == 0 ) {
return pWhere;
}
/* Generate a select expression tree to enforce the limit/offset
** term for the DELETE or UPDATE statement. For example:
** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
** becomes:
** DELETE FROM table_a WHERE rowid IN (
** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
** );
*/
pTab = pSrc->a[0].pTab;
if( HasRowid(pTab) ){
pLhs = sqlite3PExpr(pParse, TK_ROW, 0, 0);
pEList = sqlite3ExprListAppend(
pParse, 0, sqlite3PExpr(pParse, TK_ROW, 0, 0)
);
}else{
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
if( pPk->nKeyCol==1 ){
const char *zName = pTab->aCol[pPk->aiColumn[0]].zName;
pLhs = sqlite3Expr(db, TK_ID, zName);
pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, zName));
}else{
int i;
for(i=0; i<pPk->nKeyCol; i++){
Expr *p = sqlite3Expr(db, TK_ID, pTab->aCol[pPk->aiColumn[i]].zName);
pEList = sqlite3ExprListAppend(pParse, pEList, p);
}
pLhs = sqlite3PExpr(pParse, TK_VECTOR, 0, 0);
if( pLhs ){
pLhs->x.pList = sqlite3ExprListDup(db, pEList, 0);
}
}
}
/* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
** and the SELECT subtree. */
pSrc->a[0].pTab = 0;
pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0);
pSrc->a[0].pTab = pTab;
pSrc->a[0].pIBIndex = 0;
/* generate the SELECT expression tree. */
pSelect = sqlite3SelectNew(pParse, pEList, pSelectSrc, pWhere, 0 ,0,
pOrderBy,0,pLimit
);
/* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */
pInClause = sqlite3PExpr(pParse, TK_IN, pLhs, 0);
sqlite3PExprAddSelect(pParse, pInClause, pSelect);
return pInClause;
}
#endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) */
/* && !defined(SQLITE_OMIT_SUBQUERY) */
/*
** Generate code for a DELETE FROM statement.
**
** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
** \________/ \________________/
** pTabList pWhere
*/
SQLITE_PRIVATE void sqlite3DeleteFrom(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* The table from which we should delete things */
Expr *pWhere, /* The WHERE clause. May be null */
ExprList *pOrderBy, /* ORDER BY clause. May be null */
Expr *pLimit /* LIMIT clause. May be null */
){
Vdbe *v; /* The virtual database engine */
Table *pTab; /* The table from which records will be deleted */
int i; /* Loop counter */
WhereInfo *pWInfo; /* Information about the WHERE clause */
Index *pIdx; /* For looping over indices of the table */
int iTabCur; /* Cursor number for the table */
int iDataCur = 0; /* VDBE cursor for the canonical data source */
int iIdxCur = 0; /* Cursor number of the first index */
int nIdx; /* Number of indices */
sqlite3 *db; /* Main database structure */
AuthContext sContext; /* Authorization context */
NameContext sNC; /* Name context to resolve expressions in */
int iDb; /* Database number */
int memCnt = 0; /* Memory cell used for change counting */
int rcauth; /* Value returned by authorization callback */
int eOnePass; /* ONEPASS_OFF or _SINGLE or _MULTI */
int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
u8 *aToOpen = 0; /* Open cursor iTabCur+j if aToOpen[j] is true */
Index *pPk; /* The PRIMARY KEY index on the table */
int iPk = 0; /* First of nPk registers holding PRIMARY KEY value */
i16 nPk = 1; /* Number of columns in the PRIMARY KEY */
int iKey; /* Memory cell holding key of row to be deleted */
i16 nKey; /* Number of memory cells in the row key */
int iEphCur = 0; /* Ephemeral table holding all primary key values */
int iRowSet = 0; /* Register for rowset of rows to delete */
int addrBypass = 0; /* Address of jump over the delete logic */
int addrLoop = 0; /* Top of the delete loop */
int addrEphOpen = 0; /* Instruction to open the Ephemeral table */
int bComplex; /* True if there are triggers or FKs or
** subqueries in the WHERE clause */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True if attempting to delete from a view */
Trigger *pTrigger; /* List of table triggers, if required */
#endif
memset(&sContext, 0, sizeof(sContext));
db = pParse->db;
if( pParse->nErr || db->mallocFailed ){
goto delete_from_cleanup;
}
assert( pTabList->nSrc==1 );
/* Locate the table which we want to delete. This table has to be
** put in an SrcList structure because some of the subroutines we
** will be calling are designed to work with multiple tables and expect
** an SrcList* parameter instead of just a Table* parameter.
*/
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto delete_from_cleanup;
/* Figure out if we have any triggers and if the table being
** deleted from is a view
*/
#ifndef SQLITE_OMIT_TRIGGER
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
isView = pTab->pSelect!=0;
#else
# define pTrigger 0
# define isView 0
#endif
bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( !isView ){
pWhere = sqlite3LimitWhere(
pParse, pTabList, pWhere, pOrderBy, pLimit, "DELETE"
);
pOrderBy = 0;
pLimit = 0;
}
#endif
/* If pTab is really a view, make sure it has been initialized.
*/
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto delete_from_cleanup;
}
if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){
goto delete_from_cleanup;
}
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( iDb<db->nDb );
rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0,
db->aDb[iDb].zDbSName);
assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
if( rcauth==SQLITE_DENY ){
goto delete_from_cleanup;
}
assert(!isView || pTrigger);
/* Assign cursor numbers to the table and all its indices.
*/
assert( pTabList->nSrc==1 );
iTabCur = pTabList->a[0].iCursor = pParse->nTab++;
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
pParse->nTab++;
}
/* Start the view context
*/
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
/* Begin generating code.
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ){
goto delete_from_cleanup;
}
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, bComplex, iDb);
/* If we are trying to delete from a view, realize that view into
** an ephemeral table.
*/
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
if( isView ){
sqlite3MaterializeView(pParse, pTab,
pWhere, pOrderBy, pLimit, iTabCur
);
iDataCur = iIdxCur = iTabCur;
pOrderBy = 0;
pLimit = 0;
}
#endif
/* Resolve the column names in the WHERE clause.
*/
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
if( sqlite3ResolveExprNames(&sNC, pWhere) ){
goto delete_from_cleanup;
}
/* Initialize the counter of the number of rows deleted, if
** we are counting rows.
*/
if( (db->flags & SQLITE_CountRows)!=0
&& !pParse->nested
&& !pParse->pTriggerTab
){
memCnt = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
}
#ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
/* Special case: A DELETE without a WHERE clause deletes everything.
** It is easier just to erase the whole table. Prior to version 3.6.5,
** this optimization caused the row change count (the value returned by
** API function sqlite3_count_changes) to be set incorrectly.
**
** The "rcauth==SQLITE_OK" terms is the
** IMPLEMENTATION-OF: R-17228-37124 If the action code is SQLITE_DELETE and
** the callback returns SQLITE_IGNORE then the DELETE operation proceeds but
** the truncate optimization is disabled and all rows are deleted
** individually.
*/
if( rcauth==SQLITE_OK
&& pWhere==0
&& !bComplex
&& !IsVirtual(pTab)
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
&& db->xPreUpdateCallback==0
#endif
){
assert( !isView );
sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
if( HasRowid(pTab) ){
sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt ? memCnt : -1,
pTab->zName, P4_STATIC);
}
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
assert( pIdx->pSchema==pTab->pSchema );
sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
}
}else
#endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
{
u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK;
if( sNC.ncFlags & NC_VarSelect ) bComplex = 1;
wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
if( HasRowid(pTab) ){
/* For a rowid table, initialize the RowSet to an empty set */
pPk = 0;
nPk = 1;
iRowSet = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
}else{
/* For a WITHOUT ROWID table, create an ephemeral table used to
** hold all primary keys for rows to be deleted. */
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
nPk = pPk->nKeyCol;
iPk = pParse->nMem+1;
pParse->nMem += nPk;
iEphCur = pParse->nTab++;
addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk);
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
}
/* Construct a query to find the rowid or primary key for every row
** to be deleted, based on the WHERE clause. Set variable eOnePass
** to indicate the strategy used to implement this delete:
**
** ONEPASS_OFF: Two-pass approach - use a FIFO for rowids/PK values.
** ONEPASS_SINGLE: One-pass approach - at most one row deleted.
** ONEPASS_MULTI: One-pass approach - any number of rows may be deleted.
*/
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, wcf, iTabCur+1);
if( pWInfo==0 ) goto delete_from_cleanup;
eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );
assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );
if( eOnePass!=ONEPASS_SINGLE ) sqlite3MultiWrite(pParse);
if( sqlite3WhereUsesDeferredSeek(pWInfo) ){
sqlite3VdbeAddOp1(v, OP_FinishSeek, iTabCur);
}
/* Keep track of the number of rows to be deleted */
if( memCnt ){
sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
}
/* Extract the rowid or primary key for the current row */
if( pPk ){
for(i=0; i<nPk; i++){
assert( pPk->aiColumn[i]>=0 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
pPk->aiColumn[i], iPk+i);
}
iKey = iPk;
}else{
iKey = ++pParse->nMem;
sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, -1, iKey);
}
if( eOnePass!=ONEPASS_OFF ){
/* For ONEPASS, no need to store the rowid/primary-key. There is only
** one, so just keep it in its register(s) and fall through to the
** delete code. */
nKey = nPk; /* OP_Found will use an unpacked key */
aToOpen = sqlite3DbMallocRawNN(db, nIdx+2);
if( aToOpen==0 ){
sqlite3WhereEnd(pWInfo);
goto delete_from_cleanup;
}
memset(aToOpen, 1, nIdx+1);
aToOpen[nIdx+1] = 0;
if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
addrBypass = sqlite3VdbeMakeLabel(pParse);
}else{
if( pPk ){
/* Add the PK key for this row to the temporary table */
iKey = ++pParse->nMem;
nKey = 0; /* Zero tells OP_Found to use a composite key */
sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
sqlite3IndexAffinityStr(pParse->db, pPk), nPk);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEphCur, iKey, iPk, nPk);
}else{
/* Add the rowid of the row to be deleted to the RowSet */
nKey = 1; /* OP_DeferredSeek always uses a single rowid */
sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
}
sqlite3WhereEnd(pWInfo);
}
/* Unless this is a view, open cursors for the table we are
** deleting from and all its indices. If this is a view, then the
** only effect this statement has is to fire the INSTEAD OF
** triggers.
*/
if( !isView ){
int iAddrOnce = 0;
if( eOnePass==ONEPASS_MULTI ){
iAddrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
}
testcase( IsVirtual(pTab) );
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, OPFLAG_FORDELETE,
iTabCur, aToOpen, &iDataCur, &iIdxCur);
assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
if( eOnePass==ONEPASS_MULTI ){
sqlite3VdbeJumpHereOrPopInst(v, iAddrOnce);
}
}
/* Set up a loop over the rowids/primary-keys that were found in the
** where-clause loop above.
*/
if( eOnePass!=ONEPASS_OFF ){
assert( nKey==nPk ); /* OP_Found will use an unpacked key */
if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){
assert( pPk!=0 || pTab->pSelect!=0 );
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
VdbeCoverage(v);
}
}else if( pPk ){
addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
if( IsVirtual(pTab) ){
sqlite3VdbeAddOp3(v, OP_Column, iEphCur, 0, iKey);
}else{
sqlite3VdbeAddOp2(v, OP_RowData, iEphCur, iKey);
}
assert( nKey==0 ); /* OP_Found will use a composite key */
}else{
addrLoop = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, 0, iKey);
VdbeCoverage(v);
assert( nKey==1 );
}
/* Delete the row */
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
sqlite3VtabMakeWritable(pParse, pTab);
assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );
sqlite3MayAbort(pParse);
if( eOnePass==ONEPASS_SINGLE ){
sqlite3VdbeAddOp1(v, OP_Close, iTabCur);
if( sqlite3IsToplevel(pParse) ){
pParse->isMultiWrite = 0;
}
}
sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
sqlite3VdbeChangeP5(v, OE_Abort);
}else
#endif
{
int count = (pParse->nested==0); /* True to count changes */
sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
iKey, nKey, count, OE_Default, eOnePass, aiCurOnePass[1]);
}
/* End of the loop over all rowids/primary-keys. */
if( eOnePass!=ONEPASS_OFF ){
sqlite3VdbeResolveLabel(v, addrBypass);
sqlite3WhereEnd(pWInfo);
}else if( pPk ){
sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addrLoop);
}else{
sqlite3VdbeGoto(v, addrLoop);
sqlite3VdbeJumpHere(v, addrLoop);
}
} /* End non-truncate path */
/* Update the sqlite_sequence table by storing the content of the
** maximum rowid counter values recorded while inserting into
** autoincrement tables.
*/
if( pParse->nested==0 && pParse->pTriggerTab==0 ){
sqlite3AutoincrementEnd(pParse);
}
/* Return the number of rows that were deleted. If this routine is
** generating code because of a call to sqlite3NestedParse(), do not
** invoke the callback function.
*/
if( memCnt ){
sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC);
}
delete_from_cleanup:
sqlite3AuthContextPop(&sContext);
sqlite3SrcListDelete(db, pTabList);
sqlite3ExprDelete(db, pWhere);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
sqlite3ExprListDelete(db, pOrderBy);
sqlite3ExprDelete(db, pLimit);
#endif
sqlite3DbFree(db, aToOpen);
return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation). */
#ifdef isView
#undef isView
#endif
#ifdef pTrigger
#undef pTrigger
#endif
/*
** This routine generates VDBE code that causes a single row of a
** single table to be deleted. Both the original table entry and
** all indices are removed.
**
** Preconditions:
**
** 1. iDataCur is an open cursor on the btree that is the canonical data
** store for the table. (This will be either the table itself,
** in the case of a rowid table, or the PRIMARY KEY index in the case
** of a WITHOUT ROWID table.)
**
** 2. Read/write cursors for all indices of pTab must be open as
** cursor number iIdxCur+i for the i-th index.
**
** 3. The primary key for the row to be deleted must be stored in a
** sequence of nPk memory cells starting at iPk. If nPk==0 that means
** that a search record formed from OP_MakeRecord is contained in the
** single memory location iPk.
**
** eMode:
** Parameter eMode may be passed either ONEPASS_OFF (0), ONEPASS_SINGLE, or
** ONEPASS_MULTI. If eMode is not ONEPASS_OFF, then the cursor
** iDataCur already points to the row to delete. If eMode is ONEPASS_OFF
** then this function must seek iDataCur to the entry identified by iPk
** and nPk before reading from it.
**
** If eMode is ONEPASS_MULTI, then this call is being made as part
** of a ONEPASS delete that affects multiple rows. In this case, if
** iIdxNoSeek is a valid cursor number (>=0) and is not the same as
** iDataCur, then its position should be preserved following the delete
** operation. Or, if iIdxNoSeek is not a valid cursor number, the
** position of iDataCur should be preserved instead.
**
** iIdxNoSeek:
** If iIdxNoSeek is a valid cursor number (>=0) not equal to iDataCur,
** then it identifies an index cursor (from within array of cursors
** starting at iIdxCur) that already points to the index entry to be deleted.
** Except, this optimization is disabled if there are BEFORE triggers since
** the trigger body might have moved the cursor.
*/
SQLITE_PRIVATE void sqlite3GenerateRowDelete(
Parse *pParse, /* Parsing context */
Table *pTab, /* Table containing the row to be deleted */
Trigger *pTrigger, /* List of triggers to (potentially) fire */
int iDataCur, /* Cursor from which column data is extracted */
int iIdxCur, /* First index cursor */
int iPk, /* First memory cell containing the PRIMARY KEY */
i16 nPk, /* Number of PRIMARY KEY memory cells */
u8 count, /* If non-zero, increment the row change counter */
u8 onconf, /* Default ON CONFLICT policy for triggers */
u8 eMode, /* ONEPASS_OFF, _SINGLE, or _MULTI. See above */
int iIdxNoSeek /* Cursor number of cursor that does not need seeking */
){
Vdbe *v = pParse->pVdbe; /* Vdbe */
int iOld = 0; /* First register in OLD.* array */
int iLabel; /* Label resolved to end of generated code */
u8 opSeek; /* Seek opcode */
/* Vdbe is guaranteed to have been allocated by this stage. */
assert( v );
VdbeModuleComment((v, "BEGIN: GenRowDel(%d,%d,%d,%d)",
iDataCur, iIdxCur, iPk, (int)nPk));
/* Seek cursor iCur to the row to delete. If this row no longer exists
** (this can happen if a trigger program has already deleted it), do
** not attempt to delete it or fire any DELETE triggers. */
iLabel = sqlite3VdbeMakeLabel(pParse);
opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
if( eMode==ONEPASS_OFF ){
sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
VdbeCoverageIf(v, opSeek==OP_NotExists);
VdbeCoverageIf(v, opSeek==OP_NotFound);
}
/* If there are any triggers to fire, allocate a range of registers to
** use for the old.* references in the triggers. */
if( sqlite3FkRequired(pParse, pTab, 0, 0) || pTrigger ){
u32 mask; /* Mask of OLD.* columns in use */
int iCol; /* Iterator used while populating OLD.* */
int addrStart; /* Start of BEFORE trigger programs */
/* TODO: Could use temporary registers here. Also could attempt to
** avoid copying the contents of the rowid register. */
mask = sqlite3TriggerColmask(
pParse, pTrigger, 0, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onconf
);
mask |= sqlite3FkOldmask(pParse, pTab);
iOld = pParse->nMem+1;
pParse->nMem += (1 + pTab->nCol);
/* Populate the OLD.* pseudo-table register array. These values will be
** used by any BEFORE and AFTER triggers that exist. */
sqlite3VdbeAddOp2(v, OP_Copy, iPk, iOld);
for(iCol=0; iCol<pTab->nCol; iCol++){
testcase( mask!=0xffffffff && iCol==31 );
testcase( mask!=0xffffffff && iCol==32 );
if( mask==0xffffffff || (iCol<=31 && (mask & MASKBIT32(iCol))!=0) ){
int kk = sqlite3TableColumnToStorage(pTab, iCol);
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, iCol, iOld+kk+1);
}
}
/* Invoke BEFORE DELETE trigger programs. */
addrStart = sqlite3VdbeCurrentAddr(v);
sqlite3CodeRowTrigger(pParse, pTrigger,
TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel
);
/* If any BEFORE triggers were coded, then seek the cursor to the
** row to be deleted again. It may be that the BEFORE triggers moved
** the cursor or already deleted the row that the cursor was
** pointing to.
**
** Also disable the iIdxNoSeek optimization since the BEFORE trigger
** may have moved that cursor.
*/
if( addrStart<sqlite3VdbeCurrentAddr(v) ){
sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
VdbeCoverageIf(v, opSeek==OP_NotExists);
VdbeCoverageIf(v, opSeek==OP_NotFound);
testcase( iIdxNoSeek>=0 );
iIdxNoSeek = -1;
}
/* Do FK processing. This call checks that any FK constraints that
** refer to this table (i.e. constraints attached to other tables)
** are not violated by deleting this row. */
sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);
}
/* Delete the index and table entries. Skip this step if pTab is really
** a view (in which case the only effect of the DELETE statement is to
** fire the INSTEAD OF triggers).
**
** If variable 'count' is non-zero, then this OP_Delete instruction should
** invoke the update-hook. The pre-update-hook, on the other hand should
** be invoked unless table pTab is a system table. The difference is that
** the update-hook is not invoked for rows removed by REPLACE, but the
** pre-update-hook is.
*/
if( pTab->pSelect==0 ){
u8 p5 = 0;
sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek);
sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
if( pParse->nested==0 || 0==sqlite3_stricmp(pTab->zName, "sqlite_stat1") ){
sqlite3VdbeAppendP4(v, (char*)pTab, P4_TABLE);
}
if( eMode!=ONEPASS_OFF ){
sqlite3VdbeChangeP5(v, OPFLAG_AUXDELETE);
}
if( iIdxNoSeek>=0 && iIdxNoSeek!=iDataCur ){
sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek);
}
if( eMode==ONEPASS_MULTI ) p5 |= OPFLAG_SAVEPOSITION;
sqlite3VdbeChangeP5(v, p5);
}
/* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
** handle rows (possibly in other tables) that refer via a foreign key
** to the row just deleted. */
sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);
/* Invoke AFTER DELETE trigger programs. */
sqlite3CodeRowTrigger(pParse, pTrigger,
TK_DELETE, 0, TRIGGER_AFTER, pTab, iOld, onconf, iLabel
);
/* Jump here if the row had already been deleted before any BEFORE
** trigger programs were invoked. Or if a trigger program throws a
** RAISE(IGNORE) exception. */
sqlite3VdbeResolveLabel(v, iLabel);
VdbeModuleComment((v, "END: GenRowDel()"));
}
/*
** This routine generates VDBE code that causes the deletion of all
** index entries associated with a single row of a single table, pTab
**
** Preconditions:
**
** 1. A read/write cursor "iDataCur" must be open on the canonical storage
** btree for the table pTab. (This will be either the table itself
** for rowid tables or to the primary key index for WITHOUT ROWID
** tables.)
**
** 2. Read/write cursors for all indices of pTab must be open as
** cursor number iIdxCur+i for the i-th index. (The pTab->pIndex
** index is the 0-th index.)
**
** 3. The "iDataCur" cursor must be already be positioned on the row
** that is to be deleted.
*/
SQLITE_PRIVATE void sqlite3GenerateRowIndexDelete(
Parse *pParse, /* Parsing and code generating context */
Table *pTab, /* Table containing the row to be deleted */
int iDataCur, /* Cursor of table holding data. */
int iIdxCur, /* First index cursor */
int *aRegIdx, /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
int iIdxNoSeek /* Do not delete from this cursor */
){
int i; /* Index loop counter */
int r1 = -1; /* Register holding an index key */
int iPartIdxLabel; /* Jump destination for skipping partial index entries */
Index *pIdx; /* Current index */
Index *pPrior = 0; /* Prior index */
Vdbe *v; /* The prepared statement under construction */
Index *pPk; /* PRIMARY KEY index, or NULL for rowid tables */
v = pParse->pVdbe;
pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
assert( iIdxCur+i!=iDataCur || pPk==pIdx );
if( aRegIdx!=0 && aRegIdx[i]==0 ) continue;
if( pIdx==pPk ) continue;
if( iIdxCur+i==iIdxNoSeek ) continue;
VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));
r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,
&iPartIdxLabel, pPrior, r1);
sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
sqlite3VdbeChangeP5(v, 1); /* Cause IdxDelete to error if no entry found */
sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
pPrior = pIdx;
}
}
/*
** Generate code that will assemble an index key and stores it in register
** regOut. The key with be for index pIdx which is an index on pTab.
** iCur is the index of a cursor open on the pTab table and pointing to
** the entry that needs indexing. If pTab is a WITHOUT ROWID table, then
** iCur must be the cursor of the PRIMARY KEY index.
**
** Return a register number which is the first in a block of
** registers that holds the elements of the index key. The
** block of registers has already been deallocated by the time
** this routine returns.
**
** If *piPartIdxLabel is not NULL, fill it in with a label and jump
** to that label if pIdx is a partial index that should be skipped.
** The label should be resolved using sqlite3ResolvePartIdxLabel().
** A partial index should be skipped if its WHERE clause evaluates
** to false or null. If pIdx is not a partial index, *piPartIdxLabel
** will be set to zero which is an empty label that is ignored by
** sqlite3ResolvePartIdxLabel().
**
** The pPrior and regPrior parameters are used to implement a cache to
** avoid unnecessary register loads. If pPrior is not NULL, then it is
** a pointer to a different index for which an index key has just been
** computed into register regPrior. If the current pIdx index is generating
** its key into the same sequence of registers and if pPrior and pIdx share
** a column in common, then the register corresponding to that column already
** holds the correct value and the loading of that register is skipped.
** This optimization is helpful when doing a DELETE or an INTEGRITY_CHECK
** on a table with multiple indices, and especially with the ROWID or
** PRIMARY KEY columns of the index.
*/
SQLITE_PRIVATE int sqlite3GenerateIndexKey(
Parse *pParse, /* Parsing context */
Index *pIdx, /* The index for which to generate a key */
int iDataCur, /* Cursor number from which to take column data */
int regOut, /* Put the new key into this register if not 0 */
int prefixOnly, /* Compute only a unique prefix of the key */
int *piPartIdxLabel, /* OUT: Jump to this label to skip partial index */
Index *pPrior, /* Previously generated index key */
int regPrior /* Register holding previous generated key */
){
Vdbe *v = pParse->pVdbe;
int j;
int regBase;
int nCol;
if( piPartIdxLabel ){
if( pIdx->pPartIdxWhere ){
*piPartIdxLabel = sqlite3VdbeMakeLabel(pParse);
pParse->iSelfTab = iDataCur + 1;
sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel,
SQLITE_JUMPIFNULL);
pParse->iSelfTab = 0;
pPrior = 0; /* Ticket a9efb42811fa41ee 2019-11-02;
** pPartIdxWhere may have corrupted regPrior registers */
}else{
*piPartIdxLabel = 0;
}
}
nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
regBase = sqlite3GetTempRange(pParse, nCol);
if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;
for(j=0; j<nCol; j++){
if( pPrior
&& pPrior->aiColumn[j]==pIdx->aiColumn[j]
&& pPrior->aiColumn[j]!=XN_EXPR
){
/* This column was already computed by the previous index */
continue;
}
sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);
/* If the column affinity is REAL but the number is an integer, then it
** might be stored in the table as an integer (using a compact
** representation) then converted to REAL by an OP_RealAffinity opcode.
** But we are getting ready to store this value back into an index, where
** it should be converted by to INTEGER again. So omit the OP_RealAffinity
** opcode if it is present */
sqlite3VdbeDeletePriorOpcode(v, OP_RealAffinity);
}
if( regOut ){
sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut);
}
sqlite3ReleaseTempRange(pParse, regBase, nCol);
return regBase;
}
/*
** If a prior call to sqlite3GenerateIndexKey() generated a jump-over label
** because it was a partial index, then this routine should be called to
** resolve that label.
*/
SQLITE_PRIVATE void sqlite3ResolvePartIdxLabel(Parse *pParse, int iLabel){
if( iLabel ){
sqlite3VdbeResolveLabel(pParse->pVdbe, iLabel);
}
}
/************** End of delete.c **********************************************/
/************** Begin file func.c ********************************************/
/*
** 2002 February 23
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the C-language implementations for many of the SQL
** functions of SQLite. (Some function, and in particular the date and
** time functions, are implemented separately.)
*/
/* #include "sqliteInt.h" */
/* #include <stdlib.h> */
/* #include <assert.h> */
#ifndef SQLITE_OMIT_FLOATING_POINT
/* #include <math.h> */
#endif
/* #include "vdbeInt.h" */
/*
** Return the collating function associated with a function.
*/
static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
VdbeOp *pOp;
assert( context->pVdbe!=0 );
pOp = &context->pVdbe->aOp[context->iOp-1];
assert( pOp->opcode==OP_CollSeq );
assert( pOp->p4type==P4_COLLSEQ );
return pOp->p4.pColl;
}
/*
** Indicate that the accumulator load should be skipped on this
** iteration of the aggregate loop.
*/
static void sqlite3SkipAccumulatorLoad(sqlite3_context *context){
assert( context->isError<=0 );
context->isError = -1;
context->skipFlag = 1;
}
/*
** Implementation of the non-aggregate min() and max() functions
*/
static void minmaxFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int i;
int mask; /* 0 for min() or 0xffffffff for max() */
int iBest;
CollSeq *pColl;
assert( argc>1 );
mask = sqlite3_user_data(context)==0 ? 0 : -1;
pColl = sqlite3GetFuncCollSeq(context);
assert( pColl );
assert( mask==-1 || mask==0 );
iBest = 0;
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
for(i=1; i<argc; i++){
if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;
if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){
testcase( mask==0 );
iBest = i;
}
}
sqlite3_result_value(context, argv[iBest]);
}
/*
** Return the type of the argument.
*/
static void typeofFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
static const char *azType[] = { "integer", "real", "text", "blob", "null" };
int i = sqlite3_value_type(argv[0]) - 1;
UNUSED_PARAMETER(NotUsed);
assert( i>=0 && i<ArraySize(azType) );
assert( SQLITE_INTEGER==1 );
assert( SQLITE_FLOAT==2 );
assert( SQLITE_TEXT==3 );
assert( SQLITE_BLOB==4 );
assert( SQLITE_NULL==5 );
/* EVIDENCE-OF: R-01470-60482 The sqlite3_value_type(V) interface returns
** the datatype code for the initial datatype of the sqlite3_value object
** V. The returned value is one of SQLITE_INTEGER, SQLITE_FLOAT,
** SQLITE_TEXT, SQLITE_BLOB, or SQLITE_NULL. */
sqlite3_result_text(context, azType[i], -1, SQLITE_STATIC);
}
/*
** Implementation of the length() function
*/
static void lengthFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
assert( argc==1 );
UNUSED_PARAMETER(argc);
switch( sqlite3_value_type(argv[0]) ){
case SQLITE_BLOB:
case SQLITE_INTEGER:
case SQLITE_FLOAT: {
sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));
break;
}
case SQLITE_TEXT: {
const unsigned char *z = sqlite3_value_text(argv[0]);
const unsigned char *z0;
unsigned char c;
if( z==0 ) return;
z0 = z;
while( (c = *z)!=0 ){
z++;
if( c>=0xc0 ){
while( (*z & 0xc0)==0x80 ){ z++; z0++; }
}
}
sqlite3_result_int(context, (int)(z-z0));
break;
}
default: {
sqlite3_result_null(context);
break;
}
}
}
/*
** Implementation of the abs() function.
**
** IMP: R-23979-26855 The abs(X) function returns the absolute value of
** the numeric argument X.
*/
static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
assert( argc==1 );
UNUSED_PARAMETER(argc);
switch( sqlite3_value_type(argv[0]) ){
case SQLITE_INTEGER: {
i64 iVal = sqlite3_value_int64(argv[0]);
if( iVal<0 ){
if( iVal==SMALLEST_INT64 ){
/* IMP: R-31676-45509 If X is the integer -9223372036854775808
** then abs(X) throws an integer overflow error since there is no
** equivalent positive 64-bit two complement value. */
sqlite3_result_error(context, "integer overflow", -1);
return;
}
iVal = -iVal;
}
sqlite3_result_int64(context, iVal);
break;
}
case SQLITE_NULL: {
/* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */
sqlite3_result_null(context);
break;
}
default: {
/* Because sqlite3_value_double() returns 0.0 if the argument is not
** something that can be converted into a number, we have:
** IMP: R-01992-00519 Abs(X) returns 0.0 if X is a string or blob
** that cannot be converted to a numeric value.
*/
double rVal = sqlite3_value_double(argv[0]);
if( rVal<0 ) rVal = -rVal;
sqlite3_result_double(context, rVal);
break;
}
}
}
/*
** Implementation of the instr() function.
**
** instr(haystack,needle) finds the first occurrence of needle
** in haystack and returns the number of previous characters plus 1,
** or 0 if needle does not occur within haystack.
**
** If both haystack and needle are BLOBs, then the result is one more than
** the number of bytes in haystack prior to the first occurrence of needle,
** or 0 if needle never occurs in haystack.
*/
static void instrFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *zHaystack;
const unsigned char *zNeedle;
int nHaystack;
int nNeedle;
int typeHaystack, typeNeedle;
int N = 1;
int isText;
unsigned char firstChar;
sqlite3_value *pC1 = 0;
sqlite3_value *pC2 = 0;
UNUSED_PARAMETER(argc);
typeHaystack = sqlite3_value_type(argv[0]);
typeNeedle = sqlite3_value_type(argv[1]);
if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return;
nHaystack = sqlite3_value_bytes(argv[0]);
nNeedle = sqlite3_value_bytes(argv[1]);
if( nNeedle>0 ){
if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){
zHaystack = sqlite3_value_blob(argv[0]);
zNeedle = sqlite3_value_blob(argv[1]);
isText = 0;
}else if( typeHaystack!=SQLITE_BLOB && typeNeedle!=SQLITE_BLOB ){
zHaystack = sqlite3_value_text(argv[0]);
zNeedle = sqlite3_value_text(argv[1]);
isText = 1;
}else{
pC1 = sqlite3_value_dup(argv[0]);
zHaystack = sqlite3_value_text(pC1);
if( zHaystack==0 ) goto endInstrOOM;
nHaystack = sqlite3_value_bytes(pC1);
pC2 = sqlite3_value_dup(argv[1]);
zNeedle = sqlite3_value_text(pC2);
if( zNeedle==0 ) goto endInstrOOM;
nNeedle = sqlite3_value_bytes(pC2);
isText = 1;
}
if( zNeedle==0 || (nHaystack && zHaystack==0) ) goto endInstrOOM;
firstChar = zNeedle[0];
while( nNeedle<=nHaystack
&& (zHaystack[0]!=firstChar || memcmp(zHaystack, zNeedle, nNeedle)!=0)
){
N++;
do{
nHaystack--;
zHaystack++;
}while( isText && (zHaystack[0]&0xc0)==0x80 );
}
if( nNeedle>nHaystack ) N = 0;
}
sqlite3_result_int(context, N);
endInstr:
sqlite3_value_free(pC1);
sqlite3_value_free(pC2);
return;
endInstrOOM:
sqlite3_result_error_nomem(context);
goto endInstr;
}
/*
** Implementation of the printf() function.
*/
static void printfFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
PrintfArguments x;
StrAccum str;
const char *zFormat;
int n;
sqlite3 *db = sqlite3_context_db_handle(context);
if( argc>=1 && (zFormat = (const char*)sqlite3_value_text(argv[0]))!=0 ){
x.nArg = argc-1;
x.nUsed = 0;
x.apArg = argv+1;
sqlite3StrAccumInit(&str, db, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);
str.printfFlags = SQLITE_PRINTF_SQLFUNC;
sqlite3_str_appendf(&str, zFormat, &x);
n = str.nChar;
sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n,
SQLITE_DYNAMIC);
}
}
/*
** Implementation of the substr() function.
**
** substr(x,p1,p2) returns p2 characters of x[] beginning with p1.
** p1 is 1-indexed. So substr(x,1,1) returns the first character
** of x. If x is text, then we actually count UTF-8 characters.
** If x is a blob, then we count bytes.
**
** If p1 is negative, then we begin abs(p1) from the end of x[].
**
** If p2 is negative, return the p2 characters preceding p1.
*/
static void substrFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *z;
const unsigned char *z2;
int len;
int p0type;
i64 p1, p2;
int negP2 = 0;
assert( argc==3 || argc==2 );
if( sqlite3_value_type(argv[1])==SQLITE_NULL
|| (argc==3 && sqlite3_value_type(argv[2])==SQLITE_NULL)
){
return;
}
p0type = sqlite3_value_type(argv[0]);
p1 = sqlite3_value_int(argv[1]);
if( p0type==SQLITE_BLOB ){
len = sqlite3_value_bytes(argv[0]);
z = sqlite3_value_blob(argv[0]);
if( z==0 ) return;
assert( len==sqlite3_value_bytes(argv[0]) );
}else{
z = sqlite3_value_text(argv[0]);
if( z==0 ) return;
len = 0;
if( p1<0 ){
for(z2=z; *z2; len++){
SQLITE_SKIP_UTF8(z2);
}
}
}
#ifdef SQLITE_SUBSTR_COMPATIBILITY
/* If SUBSTR_COMPATIBILITY is defined then substr(X,0,N) work the same as
** as substr(X,1,N) - it returns the first N characters of X. This
** is essentially a back-out of the bug-fix in check-in [5fc125d362df4b8]
** from 2009-02-02 for compatibility of applications that exploited the
** old buggy behavior. */
if( p1==0 ) p1 = 1; /* <rdar://problem/6778339> */
#endif
if( argc==3 ){
p2 = sqlite3_value_int(argv[2]);
if( p2<0 ){
p2 = -p2;
negP2 = 1;
}
}else{
p2 = sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH];
}
if( p1<0 ){
p1 += len;
if( p1<0 ){
p2 += p1;
if( p2<0 ) p2 = 0;
p1 = 0;
}
}else if( p1>0 ){
p1--;
}else if( p2>0 ){
p2--;
}
if( negP2 ){
p1 -= p2;
if( p1<0 ){
p2 += p1;
p1 = 0;
}
}
assert( p1>=0 && p2>=0 );
if( p0type!=SQLITE_BLOB ){
while( *z && p1 ){
SQLITE_SKIP_UTF8(z);
p1--;
}
for(z2=z; *z2 && p2; p2--){
SQLITE_SKIP_UTF8(z2);
}
sqlite3_result_text64(context, (char*)z, z2-z, SQLITE_TRANSIENT,
SQLITE_UTF8);
}else{
if( p1+p2>len ){
p2 = len-p1;
if( p2<0 ) p2 = 0;
}
sqlite3_result_blob64(context, (char*)&z[p1], (u64)p2, SQLITE_TRANSIENT);
}
}
/*
** Implementation of the round() function
*/
#ifndef SQLITE_OMIT_FLOATING_POINT
static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
int n = 0;
double r;
char *zBuf;
assert( argc==1 || argc==2 );
if( argc==2 ){
if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
n = sqlite3_value_int(argv[1]);
if( n>30 ) n = 30;
if( n<0 ) n = 0;
}
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
r = sqlite3_value_double(argv[0]);
/* If Y==0 and X will fit in a 64-bit int,
** handle the rounding directly,
** otherwise use printf.
*/
if( r<-4503599627370496.0 || r>+4503599627370496.0 ){
/* The value has no fractional part so there is nothing to round */
}else if( n==0 ){
r = (double)((sqlite_int64)(r+(r<0?-0.5:+0.5)));
}else{
zBuf = sqlite3_mprintf("%.*f",n,r);
if( zBuf==0 ){
sqlite3_result_error_nomem(context);
return;
}
sqlite3AtoF(zBuf, &r, sqlite3Strlen30(zBuf), SQLITE_UTF8);
sqlite3_free(zBuf);
}
sqlite3_result_double(context, r);
}
#endif
/*
** Allocate nByte bytes of space using sqlite3Malloc(). If the
** allocation fails, call sqlite3_result_error_nomem() to notify
** the database handle that malloc() has failed and return NULL.
** If nByte is larger than the maximum string or blob length, then
** raise an SQLITE_TOOBIG exception and return NULL.
*/
static void *contextMalloc(sqlite3_context *context, i64 nByte){
char *z;
sqlite3 *db = sqlite3_context_db_handle(context);
assert( nByte>0 );
testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH] );
testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH]+1 );
if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
sqlite3_result_error_toobig(context);
z = 0;
}else{
z = sqlite3Malloc(nByte);
if( !z ){
sqlite3_result_error_nomem(context);
}
}
return z;
}
/*
** Implementation of the upper() and lower() SQL functions.
*/
static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
char *z1;
const char *z2;
int i, n;
UNUSED_PARAMETER(argc);
z2 = (char*)sqlite3_value_text(argv[0]);
n = sqlite3_value_bytes(argv[0]);
/* Verify that the call to _bytes() does not invalidate the _text() pointer */
assert( z2==(char*)sqlite3_value_text(argv[0]) );
if( z2 ){
z1 = contextMalloc(context, ((i64)n)+1);
if( z1 ){
for(i=0; i<n; i++){
z1[i] = (char)sqlite3Toupper(z2[i]);
}
sqlite3_result_text(context, z1, n, sqlite3_free);
}
}
}
static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
char *z1;
const char *z2;
int i, n;
UNUSED_PARAMETER(argc);
z2 = (char*)sqlite3_value_text(argv[0]);
n = sqlite3_value_bytes(argv[0]);
/* Verify that the call to _bytes() does not invalidate the _text() pointer */
assert( z2==(char*)sqlite3_value_text(argv[0]) );
if( z2 ){
z1 = contextMalloc(context, ((i64)n)+1);
if( z1 ){
for(i=0; i<n; i++){
z1[i] = sqlite3Tolower(z2[i]);
}
sqlite3_result_text(context, z1, n, sqlite3_free);
}
}
}
/*
** Some functions like COALESCE() and IFNULL() and UNLIKELY() are implemented
** as VDBE code so that unused argument values do not have to be computed.
** However, we still need some kind of function implementation for this
** routines in the function table. The noopFunc macro provides this.
** noopFunc will never be called so it doesn't matter what the implementation
** is. We might as well use the "version()" function as a substitute.
*/
#define noopFunc versionFunc /* Substitute function - never called */
/*
** Implementation of random(). Return a random integer.
*/
static void randomFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
sqlite_int64 r;
UNUSED_PARAMETER2(NotUsed, NotUsed2);
sqlite3_randomness(sizeof(r), &r);
if( r<0 ){
/* We need to prevent a random number of 0x8000000000000000
** (or -9223372036854775808) since when you do abs() of that
** number of you get the same value back again. To do this
** in a way that is testable, mask the sign bit off of negative
** values, resulting in a positive value. Then take the
** 2s complement of that positive value. The end result can
** therefore be no less than -9223372036854775807.
*/
r = -(r & LARGEST_INT64);
}
sqlite3_result_int64(context, r);
}
/*
** Implementation of randomblob(N). Return a random blob
** that is N bytes long.
*/
static void randomBlob(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
sqlite3_int64 n;
unsigned char *p;
assert( argc==1 );
UNUSED_PARAMETER(argc);
n = sqlite3_value_int64(argv[0]);
if( n<1 ){
n = 1;
}
p = contextMalloc(context, n);
if( p ){
sqlite3_randomness(n, p);
sqlite3_result_blob(context, (char*)p, n, sqlite3_free);
}
}
/*
** Implementation of the last_insert_rowid() SQL function. The return
** value is the same as the sqlite3_last_insert_rowid() API function.
*/
static void last_insert_rowid(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
sqlite3 *db = sqlite3_context_db_handle(context);
UNUSED_PARAMETER2(NotUsed, NotUsed2);
/* IMP: R-51513-12026 The last_insert_rowid() SQL function is a
** wrapper around the sqlite3_last_insert_rowid() C/C++ interface
** function. */
sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));
}
/*
** Implementation of the changes() SQL function.
**
** IMP: R-62073-11209 The changes() SQL function is a wrapper
** around the sqlite3_changes() C/C++ function and hence follows the same
** rules for counting changes.
*/
static void changes(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
sqlite3 *db = sqlite3_context_db_handle(context);
UNUSED_PARAMETER2(NotUsed, NotUsed2);
sqlite3_result_int(context, sqlite3_changes(db));
}
/*
** Implementation of the total_changes() SQL function. The return value is
** the same as the sqlite3_total_changes() API function.
*/
static void total_changes(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
sqlite3 *db = sqlite3_context_db_handle(context);
UNUSED_PARAMETER2(NotUsed, NotUsed2);
/* IMP: R-52756-41993 This function is a wrapper around the
** sqlite3_total_changes() C/C++ interface. */
sqlite3_result_int(context, sqlite3_total_changes(db));
}
/*
** A structure defining how to do GLOB-style comparisons.
*/
struct compareInfo {
u8 matchAll; /* "*" or "%" */
u8 matchOne; /* "?" or "_" */
u8 matchSet; /* "[" or 0 */
u8 noCase; /* true to ignore case differences */
};
/*
** For LIKE and GLOB matching on EBCDIC machines, assume that every
** character is exactly one byte in size. Also, provde the Utf8Read()
** macro for fast reading of the next character in the common case where
** the next character is ASCII.
*/
#if defined(SQLITE_EBCDIC)
# define sqlite3Utf8Read(A) (*((*A)++))
# define Utf8Read(A) (*(A++))
#else
# define Utf8Read(A) (A[0]<0x80?*(A++):sqlite3Utf8Read(&A))
#endif
static const struct compareInfo globInfo = { '*', '?', '[', 0 };
/* The correct SQL-92 behavior is for the LIKE operator to ignore
** case. Thus 'a' LIKE 'A' would be true. */
static const struct compareInfo likeInfoNorm = { '%', '_', 0, 1 };
/* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator
** is case sensitive causing 'a' LIKE 'A' to be false */
static const struct compareInfo likeInfoAlt = { '%', '_', 0, 0 };
/*
** Possible error returns from patternMatch()
*/
#define SQLITE_MATCH 0
#define SQLITE_NOMATCH 1
#define SQLITE_NOWILDCARDMATCH 2
/*
** Compare two UTF-8 strings for equality where the first string is
** a GLOB or LIKE expression. Return values:
**
** SQLITE_MATCH: Match
** SQLITE_NOMATCH: No match
** SQLITE_NOWILDCARDMATCH: No match in spite of having * or % wildcards.
**
** Globbing rules:
**
** '*' Matches any sequence of zero or more characters.
**
** '?' Matches exactly one character.
**
** [...] Matches one character from the enclosed list of
** characters.
**
** [^...] Matches one character not in the enclosed list.
**
** With the [...] and [^...] matching, a ']' character can be included
** in the list by making it the first character after '[' or '^'. A
** range of characters can be specified using '-'. Example:
** "[a-z]" matches any single lower-case letter. To match a '-', make
** it the last character in the list.
**
** Like matching rules:
**
** '%' Matches any sequence of zero or more characters
**
*** '_' Matches any one character
**
** Ec Where E is the "esc" character and c is any other
** character, including '%', '_', and esc, match exactly c.
**
** The comments within this routine usually assume glob matching.
**
** This routine is usually quick, but can be N**2 in the worst case.
*/
static int patternCompare(
const u8 *zPattern, /* The glob pattern */
const u8 *zString, /* The string to compare against the glob */
const struct compareInfo *pInfo, /* Information about how to do the compare */
u32 matchOther /* The escape char (LIKE) or '[' (GLOB) */
){
u32 c, c2; /* Next pattern and input string chars */
u32 matchOne = pInfo->matchOne; /* "?" or "_" */
u32 matchAll = pInfo->matchAll; /* "*" or "%" */
u8 noCase = pInfo->noCase; /* True if uppercase==lowercase */
const u8 *zEscaped = 0; /* One past the last escaped input char */
while( (c = Utf8Read(zPattern))!=0 ){
if( c==matchAll ){ /* Match "*" */
/* Skip over multiple "*" characters in the pattern. If there
** are also "?" characters, skip those as well, but consume a
** single character of the input string for each "?" skipped */
while( (c=Utf8Read(zPattern)) == matchAll || c == matchOne ){
if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){
return SQLITE_NOWILDCARDMATCH;
}
}
if( c==0 ){
return SQLITE_MATCH; /* "*" at the end of the pattern matches */
}else if( c==matchOther ){
if( pInfo->matchSet==0 ){
c = sqlite3Utf8Read(&zPattern);
if( c==0 ) return SQLITE_NOWILDCARDMATCH;
}else{
/* "[...]" immediately follows the "*". We have to do a slow
** recursive search in this case, but it is an unusual case. */
assert( matchOther<0x80 ); /* '[' is a single-byte character */
while( *zString ){
int bMatch = patternCompare(&zPattern[-1],zString,pInfo,matchOther);
if( bMatch!=SQLITE_NOMATCH ) return bMatch;
SQLITE_SKIP_UTF8(zString);
}
return SQLITE_NOWILDCARDMATCH;
}
}
/* At this point variable c contains the first character of the
** pattern string past the "*". Search in the input string for the
** first matching character and recursively continue the match from
** that point.
**
** For a case-insensitive search, set variable cx to be the same as
** c but in the other case and search the input string for either
** c or cx.
*/
if( c<=0x80 ){
char zStop[3];
int bMatch;
if( noCase ){
zStop[0] = sqlite3Toupper(c);
zStop[1] = sqlite3Tolower(c);
zStop[2] = 0;
}else{
zStop[0] = c;
zStop[1] = 0;
}
while(1){
zString += strcspn((const char*)zString, zStop);
if( zString[0]==0 ) break;
zString++;
bMatch = patternCompare(zPattern,zString,pInfo,matchOther);
if( bMatch!=SQLITE_NOMATCH ) return bMatch;
}
}else{
int bMatch;
while( (c2 = Utf8Read(zString))!=0 ){
if( c2!=c ) continue;
bMatch = patternCompare(zPattern,zString,pInfo,matchOther);
if( bMatch!=SQLITE_NOMATCH ) return bMatch;
}
}
return SQLITE_NOWILDCARDMATCH;
}
if( c==matchOther ){
if( pInfo->matchSet==0 ){
c = sqlite3Utf8Read(&zPattern);
if( c==0 ) return SQLITE_NOMATCH;
zEscaped = zPattern;
}else{
u32 prior_c = 0;
int seen = 0;
int invert = 0;
c = sqlite3Utf8Read(&zString);
if( c==0 ) return SQLITE_NOMATCH;
c2 = sqlite3Utf8Read(&zPattern);
if( c2=='^' ){
invert = 1;
c2 = sqlite3Utf8Read(&zPattern);
}
if( c2==']' ){
if( c==']' ) seen = 1;
c2 = sqlite3Utf8Read(&zPattern);
}
while( c2 && c2!=']' ){
if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){
c2 = sqlite3Utf8Read(&zPattern);
if( c>=prior_c && c<=c2 ) seen = 1;
prior_c = 0;
}else{
if( c==c2 ){
seen = 1;
}
prior_c = c2;
}
c2 = sqlite3Utf8Read(&zPattern);
}
if( c2==0 || (seen ^ invert)==0 ){
return SQLITE_NOMATCH;
}
continue;
}
}
c2 = Utf8Read(zString);
if( c==c2 ) continue;
if( noCase && sqlite3Tolower(c)==sqlite3Tolower(c2) && c<0x80 && c2<0x80 ){
continue;
}
if( c==matchOne && zPattern!=zEscaped && c2!=0 ) continue;
return SQLITE_NOMATCH;
}
return *zString==0 ? SQLITE_MATCH : SQLITE_NOMATCH;
}
/*
** The sqlite3_strglob() interface. Return 0 on a match (like strcmp()) and
** non-zero if there is no match.
*/
SQLITE_API int SQLITE_APICALL sqlite3_strglob(const char *zGlobPattern, const char *zString){
return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, '[');
}
/*
** The sqlite3_strlike() interface. Return 0 on a match and non-zero for
** a miss - like strcmp().
*/
SQLITE_API int SQLITE_APICALL sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){
return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc);
}
/*
** Count the number of times that the LIKE operator (or GLOB which is
** just a variation of LIKE) gets called. This is used for testing
** only.
*/
#ifdef SQLITE_TEST
SQLITE_API int sqlite3_like_count = 0;
#endif
/*
** Implementation of the like() SQL function. This function implements
** the build-in LIKE operator. The first argument to the function is the
** pattern and the second argument is the string. So, the SQL statements:
**
** A LIKE B
**
** is implemented as like(B,A).
**
** This same function (with a different compareInfo structure) computes
** the GLOB operator.
*/
static void likeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *zA, *zB;
u32 escape;
int nPat;
sqlite3 *db = sqlite3_context_db_handle(context);
struct compareInfo *pInfo = sqlite3_user_data(context);
struct compareInfo backupInfo;
#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
if( sqlite3_value_type(argv[0])==SQLITE_BLOB
|| sqlite3_value_type(argv[1])==SQLITE_BLOB
){
#ifdef SQLITE_TEST
sqlite3_like_count++;
#endif
sqlite3_result_int(context, 0);
return;
}
#endif
/* Limit the length of the LIKE or GLOB pattern to avoid problems
** of deep recursion and N*N behavior in patternCompare().
*/
nPat = sqlite3_value_bytes(argv[0]);
testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] );
testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]+1 );
if( nPat > db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){
sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);
return;
}
if( argc==3 ){
/* The escape character string must consist of a single UTF-8 character.
** Otherwise, return an error.
*/
const unsigned char *zEsc = sqlite3_value_text(argv[2]);
if( zEsc==0 ) return;
if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){
sqlite3_result_error(context,
"ESCAPE expression must be a single character", -1);
return;
}
escape = sqlite3Utf8Read(&zEsc);
if( escape==pInfo->matchAll || escape==pInfo->matchOne ){
memcpy(&backupInfo, pInfo, sizeof(backupInfo));
pInfo = &backupInfo;
if( escape==pInfo->matchAll ) pInfo->matchAll = 0;
if( escape==pInfo->matchOne ) pInfo->matchOne = 0;
}
}else{
escape = pInfo->matchSet;
}
zB = sqlite3_value_text(argv[0]);
zA = sqlite3_value_text(argv[1]);
if( zA && zB ){
#ifdef SQLITE_TEST
sqlite3_like_count++;
#endif
sqlite3_result_int(context,
patternCompare(zB, zA, pInfo, escape)==SQLITE_MATCH);
}
}
/*
** Implementation of the NULLIF(x,y) function. The result is the first
** argument if the arguments are different. The result is NULL if the
** arguments are equal to each other.
*/
static void nullifFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
CollSeq *pColl = sqlite3GetFuncCollSeq(context);
UNUSED_PARAMETER(NotUsed);
if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){
sqlite3_result_value(context, argv[0]);
}
}
/*
** Implementation of the sqlite_version() function. The result is the version
** of the SQLite library that is running.
*/
static void versionFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
UNUSED_PARAMETER2(NotUsed, NotUsed2);
/* IMP: R-48699-48617 This function is an SQL wrapper around the
** sqlite3_libversion() C-interface. */
sqlite3_result_text(context, sqlite3_libversion(), -1, SQLITE_STATIC);
}
/*
** Implementation of the sqlite_source_id() function. The result is a string
** that identifies the particular version of the source code used to build
** SQLite.
*/
static void sourceidFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **NotUsed2
){
UNUSED_PARAMETER2(NotUsed, NotUsed2);
/* IMP: R-24470-31136 This function is an SQL wrapper around the
** sqlite3_sourceid() C interface. */
sqlite3_result_text(context, sqlite3_sourceid(), -1, SQLITE_STATIC);
}
/*
** Implementation of the sqlite_log() function. This is a wrapper around
** sqlite3_log(). The return value is NULL. The function exists purely for
** its side-effects.
*/
static void errlogFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
UNUSED_PARAMETER(argc);
UNUSED_PARAMETER(context);
sqlite3_log(sqlite3_value_int(argv[0]), "%s", sqlite3_value_text(argv[1]));
}
/*
** Implementation of the sqlite_compileoption_used() function.
** The result is an integer that identifies if the compiler option
** was used to build SQLite.
*/
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
static void compileoptionusedFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const char *zOptName;
assert( argc==1 );
UNUSED_PARAMETER(argc);
/* IMP: R-39564-36305 The sqlite_compileoption_used() SQL
** function is a wrapper around the sqlite3_compileoption_used() C/C++
** function.
*/
if( (zOptName = (const char*)sqlite3_value_text(argv[0]))!=0 ){
sqlite3_result_int(context, sqlite3_compileoption_used(zOptName));
}
}
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
/*
** Implementation of the sqlite_compileoption_get() function.
** The result is a string that identifies the compiler options
** used to build SQLite.
*/
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
static void compileoptiongetFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int n;
assert( argc==1 );
UNUSED_PARAMETER(argc);
/* IMP: R-04922-24076 The sqlite_compileoption_get() SQL function
** is a wrapper around the sqlite3_compileoption_get() C/C++ function.
*/
n = sqlite3_value_int(argv[0]);
sqlite3_result_text(context, sqlite3_compileoption_get(n), -1, SQLITE_STATIC);
}
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
/* Array for converting from half-bytes (nybbles) into ASCII hex
** digits. */
static const char hexdigits[] = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
/*
** Implementation of the QUOTE() function. This function takes a single
** argument. If the argument is numeric, the return value is the same as
** the argument. If the argument is NULL, the return value is the string
** "NULL". Otherwise, the argument is enclosed in single quotes with
** single-quote escapes.
*/
static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
assert( argc==1 );
UNUSED_PARAMETER(argc);
switch( sqlite3_value_type(argv[0]) ){
case SQLITE_FLOAT: {
double r1, r2;
char zBuf[50];
r1 = sqlite3_value_double(argv[0]);
sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.15g", r1);
sqlite3AtoF(zBuf, &r2, 20, SQLITE_UTF8);
if( r1!=r2 ){
sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.20e", r1);
}
sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
break;
}
case SQLITE_INTEGER: {
sqlite3_result_value(context, argv[0]);
break;
}
case SQLITE_BLOB: {
char *zText = 0;
char const *zBlob = sqlite3_value_blob(argv[0]);
int nBlob = sqlite3_value_bytes(argv[0]);
assert( zBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */
zText = (char *)contextMalloc(context, (2*(i64)nBlob)+4);
if( zText ){
int i;
for(i=0; i<nBlob; i++){
zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];
zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];
}
zText[(nBlob*2)+2] = '\'';
zText[(nBlob*2)+3] = '\0';
zText[0] = 'X';
zText[1] = '\'';
sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
sqlite3_free(zText);
}
break;
}
case SQLITE_TEXT: {
int i,j;
u64 n;
const unsigned char *zArg = sqlite3_value_text(argv[0]);
char *z;
if( zArg==0 ) return;
for(i=0, n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
z = contextMalloc(context, ((i64)i)+((i64)n)+3);
if( z ){
z[0] = '\'';
for(i=0, j=1; zArg[i]; i++){
z[j++] = zArg[i];
if( zArg[i]=='\'' ){
z[j++] = '\'';
}
}
z[j++] = '\'';
z[j] = 0;
sqlite3_result_text(context, z, j, sqlite3_free);
}
break;
}
default: {
assert( sqlite3_value_type(argv[0])==SQLITE_NULL );
sqlite3_result_text(context, "NULL", 4, SQLITE_STATIC);
break;
}
}
}
/*
** The unicode() function. Return the integer unicode code-point value
** for the first character of the input string.
*/
static void unicodeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *z = sqlite3_value_text(argv[0]);
(void)argc;
if( z && z[0] ) sqlite3_result_int(context, sqlite3Utf8Read(&z));
}
/*
** The char() function takes zero or more arguments, each of which is
** an integer. It constructs a string where each character of the string
** is the unicode character for the corresponding integer argument.
*/
static void charFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
unsigned char *z, *zOut;
int i;
zOut = z = sqlite3_malloc64( argc*4+1 );
if( z==0 ){
sqlite3_result_error_nomem(context);
return;
}
for(i=0; i<argc; i++){
sqlite3_int64 x;
unsigned c;
x = sqlite3_value_int64(argv[i]);
if( x<0 || x>0x10ffff ) x = 0xfffd;
c = (unsigned)(x & 0x1fffff);
if( c<0x00080 ){
*zOut++ = (u8)(c&0xFF);
}else if( c<0x00800 ){
*zOut++ = 0xC0 + (u8)((c>>6)&0x1F);
*zOut++ = 0x80 + (u8)(c & 0x3F);
}else if( c<0x10000 ){
*zOut++ = 0xE0 + (u8)((c>>12)&0x0F);
*zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
*zOut++ = 0x80 + (u8)(c & 0x3F);
}else{
*zOut++ = 0xF0 + (u8)((c>>18) & 0x07);
*zOut++ = 0x80 + (u8)((c>>12) & 0x3F);
*zOut++ = 0x80 + (u8)((c>>6) & 0x3F);
*zOut++ = 0x80 + (u8)(c & 0x3F);
} \
}
sqlite3_result_text64(context, (char*)z, zOut-z, sqlite3_free, SQLITE_UTF8);
}
/*
** The hex() function. Interpret the argument as a blob. Return
** a hexadecimal rendering as text.
*/
static void hexFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int i, n;
const unsigned char *pBlob;
char *zHex, *z;
assert( argc==1 );
UNUSED_PARAMETER(argc);
pBlob = sqlite3_value_blob(argv[0]);
n = sqlite3_value_bytes(argv[0]);
assert( pBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */
z = zHex = contextMalloc(context, ((i64)n)*2 + 1);
if( zHex ){
for(i=0; i<n; i++, pBlob++){
unsigned char c = *pBlob;
*(z++) = hexdigits[(c>>4)&0xf];
*(z++) = hexdigits[c&0xf];
}
*z = 0;
sqlite3_result_text(context, zHex, n*2, sqlite3_free);
}
}
/*
** The zeroblob(N) function returns a zero-filled blob of size N bytes.
*/
static void zeroblobFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
i64 n;
int rc;
assert( argc==1 );
UNUSED_PARAMETER(argc);
n = sqlite3_value_int64(argv[0]);
if( n<0 ) n = 0;
rc = sqlite3_result_zeroblob64(context, n); /* IMP: R-00293-64994 */
if( rc ){
sqlite3_result_error_code(context, rc);
}
}
/*
** The replace() function. Three arguments are all strings: call
** them A, B, and C. The result is also a string which is derived
** from A by replacing every occurrence of B with C. The match
** must be exact. Collating sequences are not used.
*/
static void replaceFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *zStr; /* The input string A */
const unsigned char *zPattern; /* The pattern string B */
const unsigned char *zRep; /* The replacement string C */
unsigned char *zOut; /* The output */
int nStr; /* Size of zStr */
int nPattern; /* Size of zPattern */
int nRep; /* Size of zRep */
i64 nOut; /* Maximum size of zOut */
int loopLimit; /* Last zStr[] that might match zPattern[] */
int i, j; /* Loop counters */
unsigned cntExpand; /* Number zOut expansions */
sqlite3 *db = sqlite3_context_db_handle(context);
assert( argc==3 );
UNUSED_PARAMETER(argc);
zStr = sqlite3_value_text(argv[0]);
if( zStr==0 ) return;
nStr = sqlite3_value_bytes(argv[0]);
assert( zStr==sqlite3_value_text(argv[0]) ); /* No encoding change */
zPattern = sqlite3_value_text(argv[1]);
if( zPattern==0 ){
assert( sqlite3_value_type(argv[1])==SQLITE_NULL
|| sqlite3_context_db_handle(context)->mallocFailed );
return;
}
if( zPattern[0]==0 ){
assert( sqlite3_value_type(argv[1])!=SQLITE_NULL );
sqlite3_result_value(context, argv[0]);
return;
}
nPattern = sqlite3_value_bytes(argv[1]);
assert( zPattern==sqlite3_value_text(argv[1]) ); /* No encoding change */
zRep = sqlite3_value_text(argv[2]);
if( zRep==0 ) return;
nRep = sqlite3_value_bytes(argv[2]);
assert( zRep==sqlite3_value_text(argv[2]) );
nOut = nStr + 1;
assert( nOut<SQLITE_MAX_LENGTH );
zOut = contextMalloc(context, (i64)nOut);
if( zOut==0 ){
return;
}
loopLimit = nStr - nPattern;
cntExpand = 0;
for(i=j=0; i<=loopLimit; i++){
if( zStr[i]!=zPattern[0] || memcmp(&zStr[i], zPattern, nPattern) ){
zOut[j++] = zStr[i];
}else{
if( nRep>nPattern ){
nOut += nRep - nPattern;
testcase( nOut-1==db->aLimit[SQLITE_LIMIT_LENGTH] );
testcase( nOut-2==db->aLimit[SQLITE_LIMIT_LENGTH] );
if( nOut-1>db->aLimit[SQLITE_LIMIT_LENGTH] ){
sqlite3_result_error_toobig(context);
sqlite3_free(zOut);
return;
}
cntExpand++;
if( (cntExpand&(cntExpand-1))==0 ){
/* Grow the size of the output buffer only on substitutions
** whose index is a power of two: 1, 2, 4, 8, 16, 32, ... */
u8 *zOld;
zOld = zOut;
zOut = sqlite3Realloc(zOut, (int)nOut + (nOut - nStr - 1));
if( zOut==0 ){
sqlite3_result_error_nomem(context);
sqlite3_free(zOld);
return;
}
}
}
memcpy(&zOut[j], zRep, nRep);
j += nRep;
i += nPattern-1;
}
}
assert( j+nStr-i+1<=nOut );
memcpy(&zOut[j], &zStr[i], nStr-i);
j += nStr - i;
assert( j<=nOut );
zOut[j] = 0;
sqlite3_result_text(context, (char*)zOut, j, sqlite3_free);
}
/*
** Implementation of the TRIM(), LTRIM(), and RTRIM() functions.
** The userdata is 0x1 for left trim, 0x2 for right trim, 0x3 for both.
*/
static void trimFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *zIn; /* Input string */
const unsigned char *zCharSet; /* Set of characters to trim */
int nIn; /* Number of bytes in input */
int flags; /* 1: trimleft 2: trimright 3: trim */
int i; /* Loop counter */
unsigned char *aLen = 0; /* Length of each character in zCharSet */
unsigned char **azChar = 0; /* Individual characters in zCharSet */
int nChar; /* Number of characters in zCharSet */
if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
return;
}
zIn = sqlite3_value_text(argv[0]);
if( zIn==0 ) return;
nIn = sqlite3_value_bytes(argv[0]);
assert( zIn==sqlite3_value_text(argv[0]) );
if( argc==1 ){
static const unsigned char lenOne[] = { 1 };
static unsigned char * const azOne[] = { (u8*)" " };
nChar = 1;
aLen = (u8*)lenOne;
azChar = (unsigned char **)azOne;
zCharSet = 0;
}else if( (zCharSet = sqlite3_value_text(argv[1]))==0 ){
return;
}else{
const unsigned char *z;
for(z=zCharSet, nChar=0; *z; nChar++){
SQLITE_SKIP_UTF8(z);
}
if( nChar>0 ){
azChar = contextMalloc(context, ((i64)nChar)*(sizeof(char*)+1));
if( azChar==0 ){
return;
}
aLen = (unsigned char*)&azChar[nChar];
for(z=zCharSet, nChar=0; *z; nChar++){
azChar[nChar] = (unsigned char *)z;
SQLITE_SKIP_UTF8(z);
aLen[nChar] = (u8)(z - azChar[nChar]);
}
}
}
if( nChar>0 ){
flags = SQLITE_PTR_TO_INT(sqlite3_user_data(context));
if( flags & 1 ){
while( nIn>0 ){
int len = 0;
for(i=0; i<nChar; i++){
len = aLen[i];
if( len<=nIn && memcmp(zIn, azChar[i], len)==0 ) break;
}
if( i>=nChar ) break;
zIn += len;
nIn -= len;
}
}
if( flags & 2 ){
while( nIn>0 ){
int len = 0;
for(i=0; i<nChar; i++){
len = aLen[i];
if( len<=nIn && memcmp(&zIn[nIn-len],azChar[i],len)==0 ) break;
}
if( i>=nChar ) break;
nIn -= len;
}
}
if( zCharSet ){
sqlite3_free(azChar);
}
}
sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);
}
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
/*
** The "unknown" function is automatically substituted in place of
** any unrecognized function name when doing an EXPLAIN or EXPLAIN QUERY PLAN
** when the SQLITE_ENABLE_UNKNOWN_FUNCTION compile-time option is used.
** When the "sqlite3" command-line shell is built using this functionality,
** that allows an EXPLAIN or EXPLAIN QUERY PLAN for complex queries
** involving application-defined functions to be examined in a generic
** sqlite3 shell.
*/
static void unknownFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
/* no-op */
}
#endif /*SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION*/
/* IMP: R-25361-16150 This function is omitted from SQLite by default. It
** is only available if the SQLITE_SOUNDEX compile-time option is used
** when SQLite is built.
*/
#ifdef SQLITE_SOUNDEX
/*
** Compute the soundex encoding of a word.
**
** IMP: R-59782-00072 The soundex(X) function returns a string that is the
** soundex encoding of the string X.
*/
static void soundexFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
char zResult[8];
const u8 *zIn;
int i, j;
static const unsigned char iCode[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
};
assert( argc==1 );
zIn = (u8*)sqlite3_value_text(argv[0]);
if( zIn==0 ) zIn = (u8*)"";
for(i=0; zIn[i] && !sqlite3Isalpha(zIn[i]); i++){}
if( zIn[i] ){
u8 prevcode = iCode[zIn[i]&0x7f];
zResult[0] = sqlite3Toupper(zIn[i]);
for(j=1; j<4 && zIn[i]; i++){
int code = iCode[zIn[i]&0x7f];
if( code>0 ){
if( code!=prevcode ){
prevcode = code;
zResult[j++] = code + '0';
}
}else{
prevcode = 0;
}
}
while( j<4 ){
zResult[j++] = '0';
}
zResult[j] = 0;
sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
}else{
/* IMP: R-64894-50321 The string "?000" is returned if the argument
** is NULL or contains no ASCII alphabetic characters. */
sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
}
}
#endif /* SQLITE_SOUNDEX */
#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*
** A function that loads a shared-library extension then returns NULL.
*/
static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
const char *zFile = (const char *)sqlite3_value_text(argv[0]);
const char *zProc;
sqlite3 *db = sqlite3_context_db_handle(context);
char *zErrMsg = 0;
/* Disallow the load_extension() SQL function unless the SQLITE_LoadExtFunc
** flag is set. See the sqlite3_enable_load_extension() API.
*/
if( (db->flags & SQLITE_LoadExtFunc)==0 ){
sqlite3_result_error(context, "not authorized", -1);
return;
}
if( argc==2 ){
zProc = (const char *)sqlite3_value_text(argv[1]);
}else{
zProc = 0;
}
if( zFile && sqlite3_load_extension(db, zFile, zProc, &zErrMsg) ){
sqlite3_result_error(context, zErrMsg, -1);
sqlite3_free(zErrMsg);
}
}
#endif
/*
** An instance of the following structure holds the context of a
** sum() or avg() aggregate computation.
*/
typedef struct SumCtx SumCtx;
struct SumCtx {
double rSum; /* Floating point sum */
i64 iSum; /* Integer sum */
i64 cnt; /* Number of elements summed */
u8 overflow; /* True if integer overflow seen */
u8 approx; /* True if non-integer value was input to the sum */
};
/*
** Routines used to compute the sum, average, and total.
**
** The SUM() function follows the (broken) SQL standard which means
** that it returns NULL if it sums over no inputs. TOTAL returns
** 0.0 in that case. In addition, TOTAL always returns a float where
** SUM might return an integer if it never encounters a floating point
** value. TOTAL never fails, but SUM might through an exception if
** it overflows an integer.
*/
static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
SumCtx *p;
int type;
assert( argc==1 );
UNUSED_PARAMETER(argc);
p = sqlite3_aggregate_context(context, sizeof(*p));
type = sqlite3_value_numeric_type(argv[0]);
if( p && type!=SQLITE_NULL ){
p->cnt++;
if( type==SQLITE_INTEGER ){
i64 v = sqlite3_value_int64(argv[0]);
p->rSum += v;
if( (p->approx|p->overflow)==0 && sqlite3AddInt64(&p->iSum, v) ){
p->approx = p->overflow = 1;
}
}else{
p->rSum += sqlite3_value_double(argv[0]);
p->approx = 1;
}
}
}
#ifndef SQLITE_OMIT_WINDOWFUNC
static void sumInverse(sqlite3_context *context, int argc, sqlite3_value**argv){
SumCtx *p;
int type;
assert( argc==1 );
UNUSED_PARAMETER(argc);
p = sqlite3_aggregate_context(context, sizeof(*p));
type = sqlite3_value_numeric_type(argv[0]);
/* p is always non-NULL because sumStep() will have been called first
** to initialize it */
if( ALWAYS(p) && type!=SQLITE_NULL ){
assert( p->cnt>0 );
p->cnt--;
assert( type==SQLITE_INTEGER || p->approx );
if( type==SQLITE_INTEGER && p->approx==0 ){
i64 v = sqlite3_value_int64(argv[0]);
p->rSum -= v;
p->iSum -= v;
}else{
p->rSum -= sqlite3_value_double(argv[0]);
}
}
}
#else
# define sumInverse 0
#endif /* SQLITE_OMIT_WINDOWFUNC */
static void sumFinalize(sqlite3_context *context){
SumCtx *p;
p = sqlite3_aggregate_context(context, 0);
if( p && p->cnt>0 ){
if( p->overflow ){
sqlite3_result_error(context,"integer overflow",-1);
}else if( p->approx ){
sqlite3_result_double(context, p->rSum);
}else{
sqlite3_result_int64(context, p->iSum);
}
}
}
static void avgFinalize(sqlite3_context *context){
SumCtx *p;
p = sqlite3_aggregate_context(context, 0);
if( p && p->cnt>0 ){
sqlite3_result_double(context, p->rSum/(double)p->cnt);
}
}
static void totalFinalize(sqlite3_context *context){
SumCtx *p;
p = sqlite3_aggregate_context(context, 0);
/* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
sqlite3_result_double(context, p ? p->rSum : (double)0);
}
/*
** The following structure keeps track of state information for the
** count() aggregate function.
*/
typedef struct CountCtx CountCtx;
struct CountCtx {
i64 n;
#ifdef SQLITE_DEBUG
int bInverse; /* True if xInverse() ever called */
#endif
};
/*
** Routines to implement the count() aggregate function.
*/
static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
CountCtx *p;
p = sqlite3_aggregate_context(context, sizeof(*p));
if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){
p->n++;
}
#ifndef SQLITE_OMIT_DEPRECATED
/* The sqlite3_aggregate_count() function is deprecated. But just to make
** sure it still operates correctly, verify that its count agrees with our
** internal count when using count(*) and when the total count can be
** expressed as a 32-bit integer. */
assert( argc==1 || p==0 || p->n>0x7fffffff || p->bInverse
|| p->n==sqlite3_aggregate_count(context) );
#endif
}
static void countFinalize(sqlite3_context *context){
CountCtx *p;
p = sqlite3_aggregate_context(context, 0);
sqlite3_result_int64(context, p ? p->n : 0);
}
#ifndef SQLITE_OMIT_WINDOWFUNC
static void countInverse(sqlite3_context *ctx, int argc, sqlite3_value **argv){
CountCtx *p;
p = sqlite3_aggregate_context(ctx, sizeof(*p));
/* p is always non-NULL since countStep() will have been called first */
if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && ALWAYS(p) ){
p->n--;
#ifdef SQLITE_DEBUG
p->bInverse = 1;
#endif
}
}
#else
# define countInverse 0
#endif /* SQLITE_OMIT_WINDOWFUNC */
/*
** Routines to implement min() and max() aggregate functions.
*/
static void minmaxStep(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
Mem *pArg = (Mem *)argv[0];
Mem *pBest;
UNUSED_PARAMETER(NotUsed);
pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));
if( !pBest ) return;
if( sqlite3_value_type(pArg)==SQLITE_NULL ){
if( pBest->flags ) sqlite3SkipAccumulatorLoad(context);
}else if( pBest->flags ){
int max;
int cmp;
CollSeq *pColl = sqlite3GetFuncCollSeq(context);
/* This step function is used for both the min() and max() aggregates,
** the only difference between the two being that the sense of the
** comparison is inverted. For the max() aggregate, the
** sqlite3_user_data() function returns (void *)-1. For min() it
** returns (void *)db, where db is the sqlite3* database pointer.
** Therefore the next statement sets variable 'max' to 1 for the max()
** aggregate, or 0 for min().
*/
max = sqlite3_user_data(context)!=0;
cmp = sqlite3MemCompare(pBest, pArg, pColl);
if( (max && cmp<0) || (!max && cmp>0) ){
sqlite3VdbeMemCopy(pBest, pArg);
}else{
sqlite3SkipAccumulatorLoad(context);
}
}else{
pBest->db = sqlite3_context_db_handle(context);
sqlite3VdbeMemCopy(pBest, pArg);
}
}
static void minMaxValueFinalize(sqlite3_context *context, int bValue){
sqlite3_value *pRes;
pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
if( pRes ){
if( pRes->flags ){
sqlite3_result_value(context, pRes);
}
if( bValue==0 ) sqlite3VdbeMemRelease(pRes);
}
}
#ifndef SQLITE_OMIT_WINDOWFUNC
static void minMaxValue(sqlite3_context *context){
minMaxValueFinalize(context, 1);
}
#else
# define minMaxValue 0
#endif /* SQLITE_OMIT_WINDOWFUNC */
static void minMaxFinalize(sqlite3_context *context){
minMaxValueFinalize(context, 0);
}
/*
** group_concat(EXPR, ?SEPARATOR?)
*/
static void groupConcatStep(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const char *zVal;
StrAccum *pAccum;
const char *zSep;
int nVal, nSep;
assert( argc==1 || argc==2 );
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
pAccum = (StrAccum*)sqlite3_aggregate_context(context, sizeof(*pAccum));
if( pAccum ){
sqlite3 *db = sqlite3_context_db_handle(context);
int firstTerm = pAccum->mxAlloc==0;
pAccum->mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];
if( !firstTerm ){
if( argc==2 ){
zSep = (char*)sqlite3_value_text(argv[1]);
nSep = sqlite3_value_bytes(argv[1]);
}else{
zSep = ",";
nSep = 1;
}
if( zSep ) sqlite3_str_append(pAccum, zSep, nSep);
}
zVal = (char*)sqlite3_value_text(argv[0]);
nVal = sqlite3_value_bytes(argv[0]);
if( zVal ) sqlite3_str_append(pAccum, zVal, nVal);
}
}
#ifndef SQLITE_OMIT_WINDOWFUNC
static void groupConcatInverse(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int n;
StrAccum *pAccum;
assert( argc==1 || argc==2 );
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
pAccum = (StrAccum*)sqlite3_aggregate_context(context, sizeof(*pAccum));
/* pAccum is always non-NULL since groupConcatStep() will have always
** run frist to initialize it */
if( ALWAYS(pAccum) ){
n = sqlite3_value_bytes(argv[0]);
if( argc==2 ){
n += sqlite3_value_bytes(argv[1]);
}else{
n++;
}
if( n>=(int)pAccum->nChar ){
pAccum->nChar = 0;
}else{
pAccum->nChar -= n;
memmove(pAccum->zText, &pAccum->zText[n], pAccum->nChar);
}
if( pAccum->nChar==0 ) pAccum->mxAlloc = 0;
}
}
#else
# define groupConcatInverse 0
#endif /* SQLITE_OMIT_WINDOWFUNC */
static void groupConcatFinalize(sqlite3_context *context){
StrAccum *pAccum;
pAccum = sqlite3_aggregate_context(context, 0);
if( pAccum ){
if( pAccum->accError==SQLITE_TOOBIG ){
sqlite3_result_error_toobig(context);
}else if( pAccum->accError==SQLITE_NOMEM ){
sqlite3_result_error_nomem(context);
}else{
sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1,
sqlite3_free);
}
}
}
#ifndef SQLITE_OMIT_WINDOWFUNC
static void groupConcatValue(sqlite3_context *context){
sqlite3_str *pAccum;
pAccum = (sqlite3_str*)sqlite3_aggregate_context(context, 0);
if( pAccum ){
if( pAccum->accError==SQLITE_TOOBIG ){
sqlite3_result_error_toobig(context);
}else if( pAccum->accError==SQLITE_NOMEM ){
sqlite3_result_error_nomem(context);
}else{
const char *zText = sqlite3_str_value(pAccum);
sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
}
}
}
#else
# define groupConcatValue 0
#endif /* SQLITE_OMIT_WINDOWFUNC */
/*
** This routine does per-connection function registration. Most
** of the built-in functions above are part of the global function set.
** This routine only deals with those that are not global.
*/
SQLITE_PRIVATE void sqlite3RegisterPerConnectionBuiltinFunctions(sqlite3 *db){
int rc = sqlite3_overload_function(db, "MATCH", 2);
assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
if( rc==SQLITE_NOMEM ){
sqlite3OomFault(db);
}
}
/*
** Re-register the built-in LIKE functions. The caseSensitive
** parameter determines whether or not the LIKE operator is case
** sensitive.
*/
SQLITE_PRIVATE void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
struct compareInfo *pInfo;
int flags;
if( caseSensitive ){
pInfo = (struct compareInfo*)&likeInfoAlt;
flags = SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE;
}else{
pInfo = (struct compareInfo*)&likeInfoNorm;
flags = SQLITE_FUNC_LIKE;
}
sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0, 0, 0);
sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0, 0, 0);
sqlite3FindFunction(db, "like", 2, SQLITE_UTF8, 0)->funcFlags |= flags;
sqlite3FindFunction(db, "like", 3, SQLITE_UTF8, 0)->funcFlags |= flags;
}
/*
** pExpr points to an expression which implements a function. If
** it is appropriate to apply the LIKE optimization to that function
** then set aWc[0] through aWc[2] to the wildcard characters and the
** escape character and then return TRUE. If the function is not a
** LIKE-style function then return FALSE.
**
** The expression "a LIKE b ESCAPE c" is only considered a valid LIKE
** operator if c is a string literal that is exactly one byte in length.
** That one byte is stored in aWc[3]. aWc[3] is set to zero if there is
** no ESCAPE clause.
**
** *pIsNocase is set to true if uppercase and lowercase are equivalent for
** the function (default for LIKE). If the function makes the distinction
** between uppercase and lowercase (as does GLOB) then *pIsNocase is set to
** false.
*/
SQLITE_PRIVATE int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
FuncDef *pDef;
int nExpr;
if( pExpr->op!=TK_FUNCTION || !pExpr->x.pList ){
return 0;
}
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
nExpr = pExpr->x.pList->nExpr;
pDef = sqlite3FindFunction(db, pExpr->u.zToken, nExpr, SQLITE_UTF8, 0);
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
if( pDef==0 ) return 0;
#endif
if( NEVER(pDef==0) || (pDef->funcFlags & SQLITE_FUNC_LIKE)==0 ){
return 0;
}
/* The memcpy() statement assumes that the wildcard characters are
** the first three statements in the compareInfo structure. The
** asserts() that follow verify that assumption
*/
memcpy(aWc, pDef->pUserData, 3);
assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
if( nExpr<3 ){
aWc[3] = 0;
}else{
Expr *pEscape = pExpr->x.pList->a[2].pExpr;
char *zEscape;
if( pEscape->op!=TK_STRING ) return 0;
zEscape = pEscape->u.zToken;
if( zEscape[0]==0 || zEscape[1]!=0 ) return 0;
if( zEscape[0]==aWc[0] ) return 0;
if( zEscape[0]==aWc[1] ) return 0;
aWc[3] = zEscape[0];
}
*pIsNocase = (pDef->funcFlags & SQLITE_FUNC_CASE)==0;
return 1;
}
/*
** All of the FuncDef structures in the aBuiltinFunc[] array above
** to the global function hash table. This occurs at start-time (as
** a consequence of calling sqlite3_initialize()).
**
** After this routine runs
*/
SQLITE_PRIVATE void sqlite3RegisterBuiltinFunctions(void){
/*
** The following array holds FuncDef structures for all of the functions
** defined in this file.
**
** The array cannot be constant since changes are made to the
** FuncDef.pHash elements at start-time. The elements of this array
** are read-only after initialization is complete.
**
** For peak efficiency, put the most frequently used function last.
*/
static FuncDef aBuiltinFunc[] = {
/***** Functions only available with SQLITE_TESTCTRL_INTERNAL_FUNCTIONS *****/
TEST_FUNC(implies_nonnull_row, 2, INLINEFUNC_implies_nonnull_row, 0),
TEST_FUNC(expr_compare, 2, INLINEFUNC_expr_compare, 0),
TEST_FUNC(expr_implies_expr, 2, INLINEFUNC_expr_implies_expr, 0),
#ifdef SQLITE_DEBUG
TEST_FUNC(affinity, 1, INLINEFUNC_affinity, 0),
#endif
/***** Regular functions *****/
#ifdef SQLITE_SOUNDEX
FUNCTION(soundex, 1, 0, 0, soundexFunc ),
#endif
#ifndef SQLITE_OMIT_LOAD_EXTENSION
SFUNCTION(load_extension, 1, 0, 0, loadExt ),
SFUNCTION(load_extension, 2, 0, 0, loadExt ),
#endif
#if SQLITE_USER_AUTHENTICATION
FUNCTION(sqlite_crypt, 2, 0, 0, sqlite3CryptFunc ),
#endif
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
DFUNCTION(sqlite_compileoption_used,1, 0, 0, compileoptionusedFunc ),
DFUNCTION(sqlite_compileoption_get, 1, 0, 0, compileoptiongetFunc ),
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
INLINE_FUNC(unlikely, 1, INLINEFUNC_unlikely, SQLITE_FUNC_UNLIKELY),
INLINE_FUNC(likelihood, 2, INLINEFUNC_unlikely, SQLITE_FUNC_UNLIKELY),
INLINE_FUNC(likely, 1, INLINEFUNC_unlikely, SQLITE_FUNC_UNLIKELY),
#ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
FUNCTION2(sqlite_offset, 1, 0, 0, noopFunc, SQLITE_FUNC_OFFSET|
SQLITE_FUNC_TYPEOF),
#endif
FUNCTION(ltrim, 1, 1, 0, trimFunc ),
FUNCTION(ltrim, 2, 1, 0, trimFunc ),
FUNCTION(rtrim, 1, 2, 0, trimFunc ),
FUNCTION(rtrim, 2, 2, 0, trimFunc ),
FUNCTION(trim, 1, 3, 0, trimFunc ),
FUNCTION(trim, 2, 3, 0, trimFunc ),
FUNCTION(min, -1, 0, 1, minmaxFunc ),
FUNCTION(min, 0, 0, 1, 0 ),
WAGGREGATE(min, 1, 0, 1, minmaxStep, minMaxFinalize, minMaxValue, 0,
SQLITE_FUNC_MINMAX ),
FUNCTION(max, -1, 1, 1, minmaxFunc ),
FUNCTION(max, 0, 1, 1, 0 ),
WAGGREGATE(max, 1, 1, 1, minmaxStep, minMaxFinalize, minMaxValue, 0,
SQLITE_FUNC_MINMAX ),
FUNCTION2(typeof, 1, 0, 0, typeofFunc, SQLITE_FUNC_TYPEOF),
FUNCTION2(length, 1, 0, 0, lengthFunc, SQLITE_FUNC_LENGTH),
FUNCTION(instr, 2, 0, 0, instrFunc ),
FUNCTION(printf, -1, 0, 0, printfFunc ),
FUNCTION(unicode, 1, 0, 0, unicodeFunc ),
FUNCTION(char, -1, 0, 0, charFunc ),
FUNCTION(abs, 1, 0, 0, absFunc ),
#ifndef SQLITE_OMIT_FLOATING_POINT
FUNCTION(round, 1, 0, 0, roundFunc ),
FUNCTION(round, 2, 0, 0, roundFunc ),
#endif
FUNCTION(upper, 1, 0, 0, upperFunc ),
FUNCTION(lower, 1, 0, 0, lowerFunc ),
FUNCTION(hex, 1, 0, 0, hexFunc ),
INLINE_FUNC(ifnull, 2, INLINEFUNC_coalesce, 0 ),
VFUNCTION(random, 0, 0, 0, randomFunc ),
VFUNCTION(randomblob, 1, 0, 0, randomBlob ),
FUNCTION(nullif, 2, 0, 1, nullifFunc ),
DFUNCTION(sqlite_version, 0, 0, 0, versionFunc ),
DFUNCTION(sqlite_source_id, 0, 0, 0, sourceidFunc ),
FUNCTION(sqlite_log, 2, 0, 0, errlogFunc ),
FUNCTION(quote, 1, 0, 0, quoteFunc ),
VFUNCTION(last_insert_rowid, 0, 0, 0, last_insert_rowid),
VFUNCTION(changes, 0, 0, 0, changes ),
VFUNCTION(total_changes, 0, 0, 0, total_changes ),
FUNCTION(replace, 3, 0, 0, replaceFunc ),
FUNCTION(zeroblob, 1, 0, 0, zeroblobFunc ),
FUNCTION(substr, 2, 0, 0, substrFunc ),
FUNCTION(substr, 3, 0, 0, substrFunc ),
FUNCTION(substring, 2, 0, 0, substrFunc ),
FUNCTION(substring, 3, 0, 0, substrFunc ),
WAGGREGATE(sum, 1,0,0, sumStep, sumFinalize, sumFinalize, sumInverse, 0),
WAGGREGATE(total, 1,0,0, sumStep,totalFinalize,totalFinalize,sumInverse, 0),
WAGGREGATE(avg, 1,0,0, sumStep, avgFinalize, avgFinalize, sumInverse, 0),
WAGGREGATE(count, 0,0,0, countStep,
countFinalize, countFinalize, countInverse, SQLITE_FUNC_COUNT ),
WAGGREGATE(count, 1,0,0, countStep,
countFinalize, countFinalize, countInverse, 0 ),
WAGGREGATE(group_concat, 1, 0, 0, groupConcatStep,
groupConcatFinalize, groupConcatValue, groupConcatInverse, 0),
WAGGREGATE(group_concat, 2, 0, 0, groupConcatStep,
groupConcatFinalize, groupConcatValue, groupConcatInverse, 0),
LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
#ifdef SQLITE_CASE_SENSITIVE_LIKE
LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
LIKEFUNC(like, 3, &likeInfoAlt, SQLITE_FUNC_LIKE|SQLITE_FUNC_CASE),
#else
LIKEFUNC(like, 2, &likeInfoNorm, SQLITE_FUNC_LIKE),
LIKEFUNC(like, 3, &likeInfoNorm, SQLITE_FUNC_LIKE),
#endif
#ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
FUNCTION(unknown, -1, 0, 0, unknownFunc ),
#endif
FUNCTION(coalesce, 1, 0, 0, 0 ),
FUNCTION(coalesce, 0, 0, 0, 0 ),
INLINE_FUNC(coalesce, -1, INLINEFUNC_coalesce, 0 ),
INLINE_FUNC(iif, 3, INLINEFUNC_iif, 0 ),
};
#ifndef SQLITE_OMIT_ALTERTABLE
sqlite3AlterFunctions();
#endif
sqlite3WindowFunctions();
sqlite3RegisterDateTimeFunctions();
sqlite3InsertBuiltinFuncs(aBuiltinFunc, ArraySize(aBuiltinFunc));
#if 0 /* Enable to print out how the built-in functions are hashed */
{
int i;
FuncDef *p;
for(i=0; i<SQLITE_FUNC_HASH_SZ; i++){
printf("FUNC-HASH %02d:", i);
for(p=sqlite3BuiltinFunctions.a[i]; p; p=p->u.pHash){
int n = sqlite3Strlen30(p->zName);
int h = p->zName[0] + n;
printf(" %s(%d)", p->zName, h);
}
printf("\n");
}
}
#endif
}
/************** End of func.c ************************************************/
/************** Begin file fkey.c ********************************************/
/*
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used by the compiler to add foreign key
** support to compiled SQL statements.
*/
/* #include "sqliteInt.h" */
#ifndef SQLITE_OMIT_FOREIGN_KEY
#ifndef SQLITE_OMIT_TRIGGER
/*
** Deferred and Immediate FKs
** --------------------------
**
** Foreign keys in SQLite come in two flavours: deferred and immediate.
** If an immediate foreign key constraint is violated,
** SQLITE_CONSTRAINT_FOREIGNKEY is returned and the current
** statement transaction rolled back. If a
** deferred foreign key constraint is violated, no action is taken
** immediately. However if the application attempts to commit the
** transaction before fixing the constraint violation, the attempt fails.
**
** Deferred constraints are implemented using a simple counter associated
** with the database handle. The counter is set to zero each time a
** database transaction is opened. Each time a statement is executed
** that causes a foreign key violation, the counter is incremented. Each
** time a statement is executed that removes an existing violation from
** the database, the counter is decremented. When the transaction is
** committed, the commit fails if the current value of the counter is
** greater than zero. This scheme has two big drawbacks:
**
** * When a commit fails due to a deferred foreign key constraint,
** there is no way to tell which foreign constraint is not satisfied,
** or which row it is not satisfied for.
**
** * If the database contains foreign key violations when the
** transaction is opened, this may cause the mechanism to malfunction.
**
** Despite these problems, this approach is adopted as it seems simpler
** than the alternatives.
**
** INSERT operations:
**
** I.1) For each FK for which the table is the child table, search
** the parent table for a match. If none is found increment the
** constraint counter.
**
** I.2) For each FK for which the table is the parent table,
** search the child table for rows that correspond to the new
** row in the parent table. Decrement the counter for each row
** found (as the constraint is now satisfied).
**
** DELETE operations:
**
** D.1) For each FK for which the table is the child table,
** search the parent table for a row that corresponds to the
** deleted row in the child table. If such a row is not found,
** decrement the counter.
**
** D.2) For each FK for which the table is the parent table, search
** the child table for rows that correspond to the deleted row
** in the parent table. For each found increment the counter.
**
** UPDATE operations:
**
** An UPDATE command requires that all 4 steps above are taken, but only
** for FK constraints for which the affected columns are actually
** modified (values must be compared at runtime).
**
** Note that I.1 and D.1 are very similar operations, as are I.2 and D.2.
** This simplifies the implementation a bit.
**
** For the purposes of immediate FK constraints, the OR REPLACE conflict
** resolution is considered to delete rows before the new row is inserted.
** If a delete caused by OR REPLACE violates an FK constraint, an exception
** is thrown, even if the FK constraint would be satisfied after the new
** row is inserted.
**
** Immediate constraints are usually handled similarly. The only difference
** is that the counter used is stored as part of each individual statement
** object (struct Vdbe). If, after the statement has run, its immediate
** constraint counter is greater than zero,
** it returns SQLITE_CONSTRAINT_FOREIGNKEY
** and the statement transaction is rolled back. An exception is an INSERT
** statement that inserts a single row only (no triggers). In this case,
** instead of using a counter, an exception is thrown immediately if the
** INSERT violates a foreign key constraint. This is necessary as such
** an INSERT does not open a statement transaction.
**
** TODO: How should dropping a table be handled? How should renaming a
** table be handled?
**
**
** Query API Notes
** ---------------
**
** Before coding an UPDATE or DELETE row operation, the code-generator
** for those two operations needs to know whether or not the operation
** requires any FK processing and, if so, which columns of the original
** row are required by the FK processing VDBE code (i.e. if FKs were
** implemented using triggers, which of the old.* columns would be
** accessed). No information is required by the code-generator before
** coding an INSERT operation. The functions used by the UPDATE/DELETE
** generation code to query for this information are:
**
** sqlite3FkRequired() - Test to see if FK processing is required.
** sqlite3FkOldmask() - Query for the set of required old.* columns.
**
**
** Externally accessible module functions
** --------------------------------------
**
** sqlite3FkCheck() - Check for foreign key violations.
** sqlite3FkActions() - Code triggers for ON UPDATE/ON DELETE actions.
** sqlite3FkDelete() - Delete an FKey structure.
*/
/*
** VDBE Calling Convention
** -----------------------
**
** Example:
**
** For the following INSERT statement:
**
** CREATE TABLE t1(a, b INTEGER PRIMARY KEY, c);
** INSERT INTO t1 VALUES(1, 2, 3.1);
**
** Register (x): 2 (type integer)
** Register (x+1): 1 (type integer)
** Register (x+2): NULL (type NULL)
** Register (x+3): 3.1 (type real)
*/
/*
** A foreign key constraint requires that the key columns in the parent
** table are collectively subject to a UNIQUE or PRIMARY KEY constraint.
** Given that pParent is the parent table for foreign key constraint pFKey,
** search the schema for a unique index on the parent key columns.
**
** If successful, zero is returned. If the parent key is an INTEGER PRIMARY
** KEY column, then output variable *ppIdx is set to NULL. Otherwise, *ppIdx
** is set to point to the unique index.
**
** If the parent key consists of a single column (the foreign key constraint
** is not a composite foreign key), output variable *paiCol is set to NULL.
** Otherwise, it is set to point to an allocated array of size N, where
** N is the number of columns in the parent key. The first element of the
** array is the index of the child table column that is mapped by the FK
** constraint to the parent table column stored in the left-most column
** of index *ppIdx. The second element of the array is the index of the
** child table column that corresponds to the second left-most column of
** *ppIdx, and so on.
**
** If the required index cannot be found, either because:
**
** 1) The named parent key columns do not exist, or
**
** 2) The named parent key columns do exist, but are not subject to a
** UNIQUE or PRIMARY KEY constraint, or
**
** 3) No parent key columns were provided explicitly as part of the
** foreign key definition, and the parent table does not have a
** PRIMARY KEY, or
**
** 4) No parent key columns were provided explicitly as part of the
** foreign key definition, and the PRIMARY KEY of the parent table
** consists of a different number of columns to the child key in
** the child table.
**
** then non-zero is returned, and a "foreign key mismatch" error loaded
** into pParse. If an OOM error occurs, non-zero is returned and the
** pParse->db->mallocFailed flag is set.
*/
SQLITE_PRIVATE int sqlite3FkLocateIndex(
Parse *pParse, /* Parse context to store any error in */
Table *pParent, /* Parent table of FK constraint pFKey */
FKey *pFKey, /* Foreign key to find index for */
Index **ppIdx, /* OUT: Unique index on parent table */
int **paiCol /* OUT: Map of index columns in pFKey */
){
Index *pIdx = 0; /* Value to return via *ppIdx */
int *aiCol = 0; /* Value to return via *paiCol */
int nCol = pFKey->nCol; /* Number of columns in parent key */
char *zKey = pFKey->aCol[0].zCol; /* Name of left-most parent key column */
/* The caller is responsible for zeroing output parameters. */
assert( ppIdx && *ppIdx==0 );
assert( !paiCol || *paiCol==0 );
assert( pParse );
/* If this is a non-composite (single column) foreign key, check if it
** maps to the INTEGER PRIMARY KEY of table pParent. If so, leave *ppIdx
** and *paiCol set to zero and return early.
**
** Otherwise, for a composite foreign key (more than one column), allocate
** space for the aiCol array (returned via output parameter *paiCol).
** Non-composite foreign keys do not require the aiCol array.
*/
if( nCol==1 ){
/* The FK maps to the IPK if any of the following are true:
**
** 1) There is an INTEGER PRIMARY KEY column and the FK is implicitly
** mapped to the primary key of table pParent, or
** 2) The FK is explicitly mapped to a column declared as INTEGER
** PRIMARY KEY.
*/
if( pParent->iPKey>=0 ){
if( !zKey ) return 0;
if( !sqlite3StrICmp(pParent->aCol[pParent->iPKey].zName, zKey) ) return 0;
}
}else if( paiCol ){
assert( nCol>1 );
aiCol = (int *)sqlite3DbMallocRawNN(pParse->db, nCol*sizeof(int));
if( !aiCol ) return 1;
*paiCol = aiCol;
}
for(pIdx=pParent->pIndex; pIdx; pIdx=pIdx->pNext){
if( pIdx->nKeyCol==nCol && IsUniqueIndex(pIdx) && pIdx->pPartIdxWhere==0 ){
/* pIdx is a UNIQUE index (or a PRIMARY KEY) and has the right number
** of columns. If each indexed column corresponds to a foreign key
** column of pFKey, then this index is a winner. */
if( zKey==0 ){
/* If zKey is NULL, then this foreign key is implicitly mapped to
** the PRIMARY KEY of table pParent. The PRIMARY KEY index may be
** identified by the test. */
if( IsPrimaryKeyIndex(pIdx) ){
if( aiCol ){
int i;
for(i=0; i<nCol; i++) aiCol[i] = pFKey->aCol[i].iFrom;
}
break;
}
}else{
/* If zKey is non-NULL, then this foreign key was declared to
** map to an explicit list of columns in table pParent. Check if this
** index matches those columns. Also, check that the index uses
** the default collation sequences for each column. */
int i, j;
for(i=0; i<nCol; i++){
i16 iCol = pIdx->aiColumn[i]; /* Index of column in parent tbl */
const char *zDfltColl; /* Def. collation for column */
char *zIdxCol; /* Name of indexed column */
if( iCol<0 ) break; /* No foreign keys against expression indexes */
/* If the index uses a collation sequence that is different from
** the default collation sequence for the column, this index is
** unusable. Bail out early in this case. */
zDfltColl = pParent->aCol[iCol].zColl;
if( !zDfltColl ) zDfltColl = sqlite3StrBINARY;
if( sqlite3StrICmp(pIdx->azColl[i], zDfltColl) ) break;
zIdxCol = pParent->aCol[iCol].zName;
for(j=0; j<nCol; j++){
if( sqlite3StrICmp(pFKey->aCol[j].zCol, zIdxCol)==0 ){
if( aiCol ) aiCol[i] = pFKey->aCol[j].iFrom;
break;
}
}
if( j==nCol ) break;
}
if( i==nCol ) break; /* pIdx is usable */
}
}
}
if( !pIdx ){
if( !pParse->disableTriggers ){
sqlite3ErrorMsg(pParse,
"foreign key mismatch - \"%w\" referencing \"%w\"",
pFKey->pFrom->zName, pFKey->zTo);
}
sqlite3DbFree(pParse->db, aiCol);
return 1;
}
*ppIdx = pIdx;
return 0;
}
/*
** This function is called when a row is inserted into or deleted from the
** child table of foreign key constraint pFKey. If an SQL UPDATE is executed
** on the child table of pFKey, this function is invoked twice for each row
** affected - once to "delete" the old row, and then again to "insert" the
** new row.
**
** Each time it is called, this function generates VDBE code to locate the
** row in the parent table that corresponds to the row being inserted into
** or deleted from the child table. If the parent row can be found, no
** special action is taken. Otherwise, if the parent row can *not* be
** found in the parent table:
**
** Operation | FK type | Action taken
** --------------------------------------------------------------------------
** INSERT immediate Increment the "immediate constraint counter".
**
** DELETE immediate Decrement the "immediate constraint counter".
**
** INSERT deferred Increment the "deferred constraint counter".
**
** DELETE deferred Decrement the "deferred constraint counter".
**
** These operations are identified in the comment at the top of this file
** (fkey.c) as "I.1" and "D.1".
*/
static void fkLookupParent(
Parse *pParse, /* Parse context */
int iDb, /* Index of database housing pTab */
Table *pTab, /* Parent table of FK pFKey */
Index *pIdx, /* Unique index on parent key columns in pTab */
FKey *pFKey, /* Foreign key constraint */
int *aiCol, /* Map from parent key columns to child table columns */
int regData, /* Address of array containing child table row */
int nIncr, /* Increment constraint counter by this */
int isIgnore /* If true, pretend pTab contains all NULL values */
){
int i; /* Iterator variable */
Vdbe *v = sqlite3GetVdbe(pParse); /* Vdbe to add code to */
int iCur = pParse->nTab - 1; /* Cursor number to use */
int iOk = sqlite3VdbeMakeLabel(pParse); /* jump here if parent key found */
sqlite3VdbeVerifyAbortable(v,
(!pFKey->isDeferred
&& !(pParse->db->flags & SQLITE_DeferFKs)
&& !pParse->pToplevel
&& !pParse->isMultiWrite) ? OE_Abort : OE_Ignore);
/* If nIncr is less than zero, then check at runtime if there are any
** outstanding constraints to resolve. If there are not, there is no need
** to check if deleting this row resolves any outstanding violations.
**
** Check if any of the key columns in the child table row are NULL. If
** any are, then the constraint is considered satisfied. No need to
** search for a matching row in the parent table. */
if( nIncr<0 ){
sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, iOk);
VdbeCoverage(v);
}
for(i=0; i<pFKey->nCol; i++){
int iReg = sqlite3TableColumnToStorage(pFKey->pFrom,aiCol[i]) + regData + 1;
sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iOk); VdbeCoverage(v);
}
if( isIgnore==0 ){
if( pIdx==0 ){
/* If pIdx is NULL, then the parent key is the INTEGER PRIMARY KEY
** column of the parent table (table pTab). */
int iMustBeInt; /* Address of MustBeInt instruction */
int regTemp = sqlite3GetTempReg(pParse);
/* Invoke MustBeInt to coerce the child key value to an integer (i.e.
** apply the affinity of the parent key). If this fails, then there
** is no matching parent key. Before using MustBeInt, make a copy of
** the value. Otherwise, the value inserted into the child key column
** will have INTEGER affinity applied to it, which may not be correct. */
sqlite3VdbeAddOp2(v, OP_SCopy,
sqlite3TableColumnToStorage(pFKey->pFrom,aiCol[0])+1+regData, regTemp);
iMustBeInt = sqlite3VdbeAddOp2(v, OP_MustBeInt, regTemp, 0);
VdbeCoverage(v);
/* If the parent table is the same as the child table, and we are about
** to increment the constraint-counter (i.e. this is an INSERT operation),
** then check if the row being inserted matches itself. If so, do not
** increment the constraint-counter. */
if( pTab==pFKey->pFrom && nIncr==1 ){
sqlite3VdbeAddOp3(v, OP_Eq, regData, iOk, regTemp); VdbeCoverage(v);
sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
}
sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regTemp); VdbeCoverage(v);
sqlite3VdbeGoto(v, iOk);
sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2);
sqlite3VdbeJumpHere(v, iMustBeInt);
sqlite3ReleaseTempReg(pParse, regTemp);
}else{
int nCol = pFKey->nCol;
int regTemp = sqlite3GetTempRange(pParse, nCol);
int regRec = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_OpenRead, iCur, pIdx->tnum, iDb);
sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
for(i=0; i<nCol; i++){
sqlite3VdbeAddOp2(v, OP_Copy,
sqlite3TableColumnToStorage(pFKey->pFrom, aiCol[i])+1+regData,
regTemp+i);
}
/* If the parent table is the same as the child table, and we are about
** to increment the constraint-counter (i.e. this is an INSERT operation),
** then check if the row being inserted matches itself. If so, do not
** increment the constraint-counter.
**
** If any of the parent-key values are NULL, then the row cannot match
** itself. So set JUMPIFNULL to make sure we do the OP_Found if any
** of the parent-key values are NULL (at this point it is known that
** none of the child key values are).
*/
if( pTab==pFKey->pFrom && nIncr==1 ){
int iJump = sqlite3VdbeCurrentAddr(v) + nCol + 1;
for(i=0; i<nCol; i++){
int iChild = sqlite3TableColumnToStorage(pFKey->pFrom,aiCol[i])
+1+regData;
int iParent = 1+regData;
iParent += sqlite3TableColumnToStorage(pIdx->pTable,
pIdx->aiColumn[i]);
assert( pIdx->aiColumn[i]>=0 );
assert( aiCol[i]!=pTab->iPKey );
if( pIdx->aiColumn[i]==pTab->iPKey ){
/* The parent key is a composite key that includes the IPK column */
iParent = regData;
}
sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent); VdbeCoverage(v);
sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
}
sqlite3VdbeGoto(v, iOk);
}
sqlite3VdbeAddOp4(v, OP_MakeRecord, regTemp, nCol, regRec,
sqlite3IndexAffinityStr(pParse->db,pIdx), nCol);
sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0); VdbeCoverage(v);
sqlite3ReleaseTempReg(pParse, regRec);
sqlite3ReleaseTempRange(pParse, regTemp, nCol);
}
}
if( !pFKey->isDeferred && !(pParse->db->flags & SQLITE_DeferFKs)
&& !pParse->pToplevel
&& !pParse->isMultiWrite
){
/* Special case: If this is an INSERT statement that will insert exactly
** one row into the table, raise a constraint immediately instead of
** incrementing a counter. This is necessary as the VM code is being
** generated for will not open a statement transaction. */
assert( nIncr==1 );
sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
OE_Abort, 0, P4_STATIC, P5_ConstraintFK);
}else{
if( nIncr>0 && pFKey->isDeferred==0 ){
sqlite3MayAbort(pParse);
}
sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
}
sqlite3VdbeResolveLabel(v, iOk);
sqlite3VdbeAddOp1(v, OP_Close, iCur);
}
/*
** Return an Expr object that refers to a memory register corresponding
** to column iCol of table pTab.
**
** regBase is the first of an array of register that contains the data
** for pTab. regBase itself holds the rowid. regBase+1 holds the first
** column. regBase+2 holds the second column, and so forth.
*/
static Expr *exprTableRegister(
Parse *pParse, /* Parsing and code generating context */
Table *pTab, /* The table whose content is at r[regBase]... */
int regBase, /* Contents of table pTab */
i16 iCol /* Which column of pTab is desired */
){
Expr *pExpr;
Column *pCol;
const char *zColl;
sqlite3 *db = pParse->db;
pExpr = sqlite3Expr(db, TK_REGISTER, 0);
if( pExpr ){
if( iCol>=0 && iCol!=pTab->iPKey ){
pCol = &pTab->aCol[iCol];
pExpr->iTable = regBase + sqlite3TableColumnToStorage(pTab,iCol) + 1;
pExpr->affExpr = pCol->affinity;
zColl = pCol->zColl;
if( zColl==0 ) zColl = db->pDfltColl->zName;
pExpr = sqlite3ExprAddCollateString(pParse, pExpr, zColl);
}else{
pExpr->iTable = regBase;
pExpr->affExpr = SQLITE_AFF_INTEGER;
}
}
return pExpr;
}
/*
** Return an Expr object that refers to column iCol of table pTab which
** has cursor iCur.
*/
static Expr *exprTableColumn(
sqlite3 *db, /* The database connection */
Table *pTab, /* The table whose column is desired */
int iCursor, /* The open cursor on the table */
i16 iCol /* The column that is wanted */
){
Expr *pExpr = sqlite3Expr(db, TK_COLUMN, 0);
if( pExpr ){
pExpr->y.pTab = pTab;
pExpr->iTable = iCursor;
pExpr->iColumn = iCol;
}
return pExpr;
}
/*
** This function is called to generate code executed when a row is deleted
** from the parent table of foreign key constraint pFKey and, if pFKey is
** deferred, when a row is inserted into the same table. When generating
** code for an SQL UPDATE operation, this function may be called twice -
** once to "delete" the old row and once to "insert" the new row.
**
** Parameter nIncr is passed -1 when inserting a row (as this may decrease
** the number of FK violations in the db) or +1 when deleting one (as this
** may increase the number of FK constraint problems).
**
** The code generated by this function scans through the rows in the child
** table that correspond to the parent table row being deleted or inserted.
** For each child row found, one of the following actions is taken:
**
** Operation | FK type | Action taken
** --------------------------------------------------------------------------
** DELETE immediate Increment the "immediate constraint counter".
** Or, if the ON (UPDATE|DELETE) action is RESTRICT,
** throw a "FOREIGN KEY constraint failed" exception.
**
** INSERT immediate Decrement the "immediate constraint counter".
**
** DELETE deferred Increment the "deferred constraint counter".
** Or, if the ON (UPDATE|DELETE) action is RESTRICT,
** throw a "FOREIGN KEY constraint failed" exception.
**
** INSERT deferred Decrement the "deferred constraint counter".
**
** These operations are identified in the comment at the top of this file
** (fkey.c) as "I.2" and "D.2".
*/
static void fkScanChildren(
Parse *pParse, /* Parse context */
SrcList *pSrc, /* The child table to be scanned */
Table *pTab, /* The parent table */
Index *pIdx, /* Index on parent covering the foreign key */
FKey *pFKey, /* The foreign key linking pSrc to pTab */
int *aiCol, /* Map from pIdx cols to child table cols */
int regData, /* Parent row data starts here */
int nIncr /* Amount to increment deferred counter by */
){
sqlite3 *db = pParse->db; /* Database handle */
int i; /* Iterator variable */
Expr *pWhere = 0; /* WHERE clause to scan with */
NameContext sNameContext; /* Context used to resolve WHERE clause */
WhereInfo *pWInfo; /* Context used by sqlite3WhereXXX() */
int iFkIfZero = 0; /* Address of OP_FkIfZero */
Vdbe *v = sqlite3GetVdbe(pParse);
assert( pIdx==0 || pIdx->pTable==pTab );
assert( pIdx==0 || pIdx->nKeyCol==pFKey->nCol );
assert( pIdx!=0 || pFKey->nCol==1 );
assert( pIdx!=0 || HasRowid(pTab) );
if( nIncr<0 ){
iFkIfZero = sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, 0);
VdbeCoverage(v);
}
/* Create an Expr object representing an SQL expression like:
**
** <parent-key1> = <child-key1> AND <parent-key2> = <child-key2> ...
**
** The collation sequence used for the comparison should be that of
** the parent key columns. The affinity of the parent key column should
** be applied to each child key value before the comparison takes place.
*/
for(i=0; i<pFKey->nCol; i++){
Expr *pLeft; /* Value from parent table row */
Expr *pRight; /* Column ref to child table */
Expr *pEq; /* Expression (pLeft = pRight) */
i16 iCol; /* Index of column in child table */
const char *zCol; /* Name of column in child table */
iCol = pIdx ? pIdx->aiColumn[i] : -1;
pLeft = exprTableRegister(pParse, pTab, regData, iCol);
iCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
assert( iCol>=0 );
zCol = pFKey->pFrom->aCol[iCol].zName;
pRight = sqlite3Expr(db, TK_ID, zCol);
pEq = sqlite3PExpr(pParse, TK_EQ, pLeft, pRight);
pWhere = sqlite3ExprAnd(pParse, pWhere, pEq);
}
/* If the child table is the same as the parent table, then add terms
** to the WHERE clause that prevent this entry from being scanned.
** The added WHERE clause terms are like this:
**
** $current_rowid!=rowid
** NOT( $current_a==a AND $current_b==b AND ... )
**
** The first form is used for rowid tables. The second form is used
** for WITHOUT ROWID tables. In the second form, the *parent* key is
** (a,b,...). Either the parent or primary key could be used to
** uniquely identify the current row, but the parent key is more convenient
** as the required values have already been loaded into registers
** by the caller.
*/
if( pTab==pFKey->pFrom && nIncr>0 ){
Expr *pNe; /* Expression (pLeft != pRight) */
Expr *pLeft; /* Value from parent table row */
Expr *pRight; /* Column ref to child table */
if( HasRowid(pTab) ){
pLeft = exprTableRegister(pParse, pTab, regData, -1);
pRight = exprTableColumn(db, pTab, pSrc->a[0].iCursor, -1);
pNe = sqlite3PExpr(pParse, TK_NE, pLeft, pRight);
}else{
Expr *pEq, *pAll = 0;
assert( pIdx!=0 );
for(i=0; i<pIdx->nKeyCol; i++){
i16 iCol = pIdx->aiColumn[i];
assert( iCol>=0 );
pLeft = exprTableRegister(pParse, pTab, regData, iCol);
pRight = sqlite3Expr(db, TK_ID, pTab->aCol[iCol].zName);
pEq = sqlite3PExpr(pParse, TK_IS, pLeft, pRight);
pAll = sqlite3ExprAnd(pParse, pAll, pEq);
}
pNe = sqlite3PExpr(pParse, TK_NOT, pAll, 0);
}
pWhere = sqlite3ExprAnd(pParse, pWhere, pNe);
}
/* Resolve the references in the WHERE clause. */
memset(&sNameContext, 0, sizeof(NameContext));
sNameContext.pSrcList = pSrc;
sNameContext.pParse = pParse;
sqlite3ResolveExprNames(&sNameContext, pWhere);
/* Create VDBE to loop through the entries in pSrc that match the WHERE
** clause. For each row found, increment either the deferred or immediate
** foreign key constraint counter. */
if( pParse->nErr==0 ){
pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);
sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
if( pWInfo ){
sqlite3WhereEnd(pWInfo);
}
}
/* Clean up the WHERE clause constructed above. */
sqlite3ExprDelete(db, pWhere);
if( iFkIfZero ){
sqlite3VdbeJumpHereOrPopInst(v, iFkIfZero);
}
}
/*
** This function returns a linked list of FKey objects (connected by
** FKey.pNextTo) holding all children of table pTab. For example,
** given the following schema:
**
** CREATE TABLE t1(a PRIMARY KEY);
** CREATE TABLE t2(b REFERENCES t1(a);
**
** Calling this function with table "t1" as an argument returns a pointer
** to the FKey structure representing the foreign key constraint on table
** "t2". Calling this function with "t2" as the argument would return a
** NULL pointer (as there are no FK constraints for which t2 is the parent
** table).
*/
SQLITE_PRIVATE FKey *sqlite3FkReferences(Table *pTab){
return (FKey *)sqlite3HashFind(&pTab->pSchema->fkeyHash, pTab->zName);
}
/*
** The second argument is a Trigger structure allocated by the
** fkActionTrigger() routine. This function deletes the Trigger structure
** and all of its sub-components.
**
** The Trigger structure or any of its sub-components may be allocated from
** the lookaside buffer belonging to database handle dbMem.
*/
static void fkTriggerDelete(sqlite3 *dbMem, Trigger *p){
if( p ){
TriggerStep *pStep = p->step_list;
sqlite3ExprDelete(dbMem, pStep->pWhere);
sqlite3ExprListDelete(dbMem, pStep->pExprList);
sqlite3SelectDelete(dbMem, pStep->pSelect);
sqlite3ExprDelete(dbMem, p->pWhen);
sqlite3DbFree(dbMem, p);
}
}
/*
** This function is called to generate code that runs when table pTab is
** being dropped from the database. The SrcList passed as the second argument
** to this function contains a single entry guaranteed to resolve to
** table pTab.
**
** Normally, no code is required. However, if either
**
** (a) The table is the parent table of a FK constraint, or
** (b) The table is the child table of a deferred FK constraint and it is
** determined at runtime that there are outstanding deferred FK
** constraint violations in the database,
**
** then the equivalent of "DELETE FROM <tbl>" is executed before dropping
** the table from the database. Triggers are disabled while running this
** DELETE, but foreign key actions are not.
*/
SQLITE_PRIVATE void sqlite3FkDropTable(Parse *pParse, SrcList *pName, Table *pTab){
sqlite3 *db = pParse->db;
if( (db->flags&SQLITE_ForeignKeys) && !IsVirtual(pTab) ){
int iSkip = 0;
Vdbe *v = sqlite3GetVdbe(pParse);
assert( v ); /* VDBE has already been allocated */
assert( pTab->pSelect==0 ); /* Not a view */
if( sqlite3FkReferences(pTab)==0 ){
/* Search for a deferred foreign key constraint for which this table
** is the child table. If one cannot be found, return without
** generating any VDBE code. If one can be found, then jump over
** the entire DELETE if there are no outstanding deferred constraints
** when this statement is run. */
FKey *p;
for(p=pTab->pFKey; p; p=p->pNextFrom){
if( p->isDeferred || (db->flags & SQLITE_DeferFKs) ) break;
}
if( !p ) return;
iSkip = sqlite3VdbeMakeLabel(pParse);
sqlite3VdbeAddOp2(v, OP_FkIfZero, 1, iSkip); VdbeCoverage(v);
}
pParse->disableTriggers = 1;
sqlite3DeleteFrom(pParse, sqlite3SrcListDup(db, pName, 0), 0, 0, 0);
pParse->disableTriggers = 0;
/* If the DELETE has generated immediate foreign key constraint
** violations, halt the VDBE and return an error at this point, before
** any modifications to the schema are made. This is because statement
** transactions are not able to rollback schema changes.
**
** If the SQLITE_DeferFKs flag is set, then this is not required, as
** the statement transaction will not be rolled back even if FK
** constraints are violated.
*/
if( (db->flags & SQLITE_DeferFKs)==0 ){
sqlite3VdbeVerifyAbortable(v, OE_Abort);
sqlite3VdbeAddOp2(v, OP_FkIfZero, 0, sqlite3VdbeCurrentAddr(v)+2);
VdbeCoverage(v);
sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_FOREIGNKEY,
OE_Abort, 0, P4_STATIC, P5_ConstraintFK);
}
if( iSkip ){
sqlite3VdbeResolveLabel(v, iSkip);
}
}
}
/*
** The second argument points to an FKey object representing a foreign key
** for which pTab is the child table. An UPDATE statement against pTab
** is currently being processed. For each column of the table that is
** actually updated, the corresponding element in the aChange[] array
** is zero or greater (if a column is unmodified the corresponding element
** is set to -1). If the rowid column is modified by the UPDATE statement
** the bChngRowid argument is non-zero.
**
** This function returns true if any of the columns that are part of the
** child key for FK constraint *p are modified.
*/
static int fkChildIsModified(
Table *pTab, /* Table being updated */
FKey *p, /* Foreign key for which pTab is the child */
int *aChange, /* Array indicating modified columns */
int bChngRowid /* True if rowid is modified by this update */
){
int i;
for(i=0; i<p->nCol; i++){
int iChildKey = p->aCol[i].iFrom;
if( aChange[iChildKey]>=0 ) return 1;
if( iChildKey==pTab->iPKey && bChngRowid ) return 1;
}
return 0;
}
/*
** The second argument points to an FKey object representing a foreign key
** for which pTab is the parent table. An UPDATE statement against pTab
** is currently being processed. For each column of the table that is
** actually updated, the corresponding element in the aChange[] array
** is zero or greater (if a column is unmodified the corresponding element
** is set to -1). If the rowid column is modified by the UPDATE statement
** the bChngRowid argument is non-zero.
**
** This function returns true if any of the columns that are part of the
** parent key for FK constraint *p are modified.
*/
static int fkParentIsModified(
Table *pTab,
FKey *p,
int *aChange,
int bChngRowid
){
int i;
for(i=0; i<p->nCol; i++){
char *zKey = p->aCol[i].zCol;
int iKey;
for(iKey=0; iKey<pTab->nCol; iKey++){
if( aChange[iKey]>=0 || (iKey==pTab->iPKey && bChngRowid) ){
Column *pCol = &pTab->aCol[iKey];
if( zKey ){
if( 0==sqlite3StrICmp(pCol->zName, zKey) ) return 1;
}else if( pCol->colFlags & COLFLAG_PRIMKEY ){
return 1;
}
}
}
}
return 0;
}
/*
** Return true if the parser passed as the first argument is being
** used to code a trigger that is really a "SET NULL" action belonging
** to trigger pFKey.
*/
static int isSetNullAction(Parse *pParse, FKey *pFKey){
Parse *pTop = sqlite3ParseToplevel(pParse);
if( pTop->pTriggerPrg ){
Trigger *p = pTop->pTriggerPrg->pTrigger;
if( (p==pFKey->apTrigger[0] && pFKey->aAction[0]==OE_SetNull)
|| (p==pFKey->apTrigger[1] && pFKey->aAction[1]==OE_SetNull)
){
return 1;
}
}
return 0;
}
/*
** This function is called when inserting, deleting or updating a row of
** table pTab to generate VDBE code to perform foreign key constraint
** processing for the operation.
**
** For a DELETE operation, parameter regOld is passed the index of the
** first register in an array of (pTab->nCol+1) registers containing the
** rowid of the row being deleted, followed by each of the column values
** of the row being deleted, from left to right. Parameter regNew is passed
** zero in this case.
**
** For an INSERT operation, regOld is passed zero and regNew is passed the
** first register of an array of (pTab->nCol+1) registers containing the new
** row data.
**
** For an UPDATE operation, this function is called twice. Once before
** the original record is deleted from the table using the calling convention
** described for DELETE. Then again after the original record is deleted
** but before the new record is inserted using the INSERT convention.
*/
SQLITE_PRIVATE void sqlite3FkCheck(
Parse *pParse, /* Parse context */
Table *pTab, /* Row is being deleted from this table */
int regOld, /* Previous row data is stored here */
int regNew, /* New row data is stored here */
int *aChange, /* Array indicating UPDATEd columns (or 0) */
int bChngRowid /* True if rowid is UPDATEd */
){
sqlite3 *db = pParse->db; /* Database handle */
FKey *pFKey; /* Used to iterate through FKs */
int iDb; /* Index of database containing pTab */
const char *zDb; /* Name of database containing pTab */
int isIgnoreErrors = pParse->disableTriggers;
/* Exactly one of regOld and regNew should be non-zero. */
assert( (regOld==0)!=(regNew==0) );
/* If foreign-keys are disabled, this function is a no-op. */
if( (db->flags&SQLITE_ForeignKeys)==0 ) return;
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
zDb = db->aDb[iDb].zDbSName;
/* Loop through all the foreign key constraints for which pTab is the
** child table (the table that the foreign key definition is part of). */
for(pFKey=pTab->pFKey; pFKey; pFKey=pFKey->pNextFrom){
Table *pTo; /* Parent table of foreign key pFKey */
Index *pIdx = 0; /* Index on key columns in pTo */
int *aiFree = 0;
int *aiCol;
int iCol;
int i;
int bIgnore = 0;
if( aChange
&& sqlite3_stricmp(pTab->zName, pFKey->zTo)!=0
&& fkChildIsModified(pTab, pFKey, aChange, bChngRowid)==0
){
continue;
}
/* Find the parent table of this foreign key. Also find a unique index
** on the parent key columns in the parent table. If either of these
** schema items cannot be located, set an error in pParse and return
** early. */
if( pParse->disableTriggers ){
pTo = sqlite3FindTable(db, pFKey->zTo, zDb);
}else{
pTo = sqlite3LocateTable(pParse, 0, pFKey->zTo, zDb);
}
if( !pTo || sqlite3FkLocateIndex(pParse, pTo, pFKey, &pIdx, &aiFree) ){
assert( isIgnoreErrors==0 || (regOld!=0 && regNew==0) );
if( !isIgnoreErrors || db->mallocFailed ) return;
if( pTo==0 ){
/* If isIgnoreErrors is true, then a table is being dropped. In this
** case SQLite runs a "DELETE FROM xxx" on the table being dropped
** before actually dropping it in order to check FK constraints.
** If the parent table of an FK constraint on the current table is
** missing, behave as if it is empty. i.e. decrement the relevant
** FK counter for each row of the current table with non-NULL keys.
*/
Vdbe *v = sqlite3GetVdbe(pParse);
int iJump = sqlite3VdbeCurrentAddr(v) + pFKey->nCol + 1;
for(i=0; i<pFKey->nCol; i++){
int iFromCol, iReg;
iFromCol = pFKey->aCol[i].iFrom;
iReg = sqlite3TableColumnToStorage(pFKey->pFrom,iFromCol) + regOld+1;
sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iJump); VdbeCoverage(v);
}
sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, -1);
}
continue;
}
assert( pFKey->nCol==1 || (aiFree && pIdx) );
if( aiFree ){
aiCol = aiFree;
}else{
iCol = pFKey->aCol[0].iFrom;
aiCol = &iCol;
}
for(i=0; i<pFKey->nCol; i++){
if( aiCol[i]==pTab->iPKey ){
aiCol[i] = -1;
}
assert( pIdx==0 || pIdx->aiColumn[i]>=0 );
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Request permission to read the parent key columns. If the
** authorization callback returns SQLITE_IGNORE, behave as if any
** values read from the parent table are NULL. */
if( db->xAuth ){
int rcauth;
char *zCol = pTo->aCol[pIdx ? pIdx->aiColumn[i] : pTo->iPKey].zName;
rcauth = sqlite3AuthReadCol(pParse, pTo->zName, zCol, iDb);
bIgnore = (rcauth==SQLITE_IGNORE);
}
#endif
}
/* Take a shared-cache advisory read-lock on the parent table. Allocate
** a cursor to use to search the unique index on the parent key columns
** in the parent table. */
sqlite3TableLock(pParse, iDb, pTo->tnum, 0, pTo->zName);
pParse->nTab++;
if( regOld!=0 ){
/* A row is being removed from the child table. Search for the parent.
** If the parent does not exist, removing the child row resolves an
** outstanding foreign key constraint violation. */
fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regOld, -1, bIgnore);
}
if( regNew!=0 && !isSetNullAction(pParse, pFKey) ){
/* A row is being added to the child table. If a parent row cannot
** be found, adding the child row has violated the FK constraint.
**
** If this operation is being performed as part of a trigger program
** that is actually a "SET NULL" action belonging to this very
** foreign key, then omit this scan altogether. As all child key
** values are guaranteed to be NULL, it is not possible for adding
** this row to cause an FK violation. */
fkLookupParent(pParse, iDb, pTo, pIdx, pFKey, aiCol, regNew, +1, bIgnore);
}
sqlite3DbFree(db, aiFree);
}
/* Loop through all the foreign key constraints that refer to this table.
** (the "child" constraints) */
for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
Index *pIdx = 0; /* Foreign key index for pFKey */
SrcList *pSrc;
int *aiCol = 0;
if( aChange && fkParentIsModified(pTab, pFKey, aChange, bChngRowid)==0 ){
continue;
}
if( !pFKey->isDeferred && !(db->flags & SQLITE_DeferFKs)
&& !pParse->pToplevel && !pParse->isMultiWrite
){
assert( regOld==0 && regNew!=0 );
/* Inserting a single row into a parent table cannot cause (or fix)
** an immediate foreign key violation. So do nothing in this case. */
continue;
}
if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ){
if( !isIgnoreErrors || db->mallocFailed ) return;
continue;
}
assert( aiCol || pFKey->nCol==1 );
/* Create a SrcList structure containing the child table. We need the
** child table as a SrcList for sqlite3WhereBegin() */
pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
if( pSrc ){
struct SrcList_item *pItem = pSrc->a;
pItem->pTab = pFKey->pFrom;
pItem->zName = pFKey->pFrom->zName;
pItem->pTab->nTabRef++;
pItem->iCursor = pParse->nTab++;
if( regNew!=0 ){
fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regNew, -1);
}
if( regOld!=0 ){
int eAction = pFKey->aAction[aChange!=0];
fkScanChildren(pParse, pSrc, pTab, pIdx, pFKey, aiCol, regOld, 1);
/* If this is a deferred FK constraint, or a CASCADE or SET NULL
** action applies, then any foreign key violations caused by
** removing the parent key will be rectified by the action trigger.
** So do not set the "may-abort" flag in this case.
**
** Note 1: If the FK is declared "ON UPDATE CASCADE", then the
** may-abort flag will eventually be set on this statement anyway
** (when this function is called as part of processing the UPDATE
** within the action trigger).
**
** Note 2: At first glance it may seem like SQLite could simply omit
** all OP_FkCounter related scans when either CASCADE or SET NULL
** applies. The trouble starts if the CASCADE or SET NULL action
** trigger causes other triggers or action rules attached to the
** child table to fire. In these cases the fk constraint counters
** might be set incorrectly if any OP_FkCounter related scans are
** omitted. */
if( !pFKey->isDeferred && eAction!=OE_Cascade && eAction!=OE_SetNull ){
sqlite3MayAbort(pParse);
}
}
pItem->zName = 0;
sqlite3SrcListDelete(db, pSrc);
}
sqlite3DbFree(db, aiCol);
}
}
#define COLUMN_MASK(x) (((x)>31) ? 0xffffffff : ((u32)1<<(x)))
/*
** This function is called before generating code to update or delete a
** row contained in table pTab.
*/
SQLITE_PRIVATE u32 sqlite3FkOldmask(
Parse *pParse, /* Parse context */
Table *pTab /* Table being modified */
){
u32 mask = 0;
if( pParse->db->flags&SQLITE_ForeignKeys ){
FKey *p;
int i;
for(p=pTab->pFKey; p; p=p->pNextFrom){
for(i=0; i<p->nCol; i++) mask |= COLUMN_MASK(p->aCol[i].iFrom);
}
for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
Index *pIdx = 0;
sqlite3FkLocateIndex(pParse, pTab, p, &pIdx, 0);
if( pIdx ){
for(i=0; i<pIdx->nKeyCol; i++){
assert( pIdx->aiColumn[i]>=0 );
mask |= COLUMN_MASK(pIdx->aiColumn[i]);
}
}
}
}
return mask;
}
/*
** This function is called before generating code to update or delete a
** row contained in table pTab. If the operation is a DELETE, then
** parameter aChange is passed a NULL value. For an UPDATE, aChange points
** to an array of size N, where N is the number of columns in table pTab.
** If the i'th column is not modified by the UPDATE, then the corresponding
** entry in the aChange[] array is set to -1. If the column is modified,
** the value is 0 or greater. Parameter chngRowid is set to true if the
** UPDATE statement modifies the rowid fields of the table.
**
** If any foreign key processing will be required, this function returns
** non-zero. If there is no foreign key related processing, this function
** returns zero.
**
** For an UPDATE, this function returns 2 if:
**
** * There are any FKs for which pTab is the child and the parent table, or
** * the UPDATE modifies one or more parent keys for which the action is
** not "NO ACTION" (i.e. is CASCADE, SET DEFAULT or SET NULL).
**
** Or, assuming some other foreign key processing is required, 1.
*/
SQLITE_PRIVATE int sqlite3FkRequired(
Parse *pParse, /* Parse context */
Table *pTab, /* Table being modified */
int *aChange, /* Non-NULL for UPDATE operations */
int chngRowid /* True for UPDATE that affects rowid */
){
int eRet = 0;
if( pParse->db->flags&SQLITE_ForeignKeys ){
if( !aChange ){
/* A DELETE operation. Foreign key processing is required if the
** table in question is either the child or parent table for any
** foreign key constraint. */
eRet = (sqlite3FkReferences(pTab) || pTab->pFKey);
}else{
/* This is an UPDATE. Foreign key processing is only required if the
** operation modifies one or more child or parent key columns. */
FKey *p;
/* Check if any child key columns are being modified. */
for(p=pTab->pFKey; p; p=p->pNextFrom){
if( 0==sqlite3_stricmp(pTab->zName, p->zTo) ) return 2;
if( fkChildIsModified(pTab, p, aChange, chngRowid) ){
eRet = 1;
}
}
/* Check if any parent key columns are being modified. */
for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
if( fkParentIsModified(pTab, p, aChange, chngRowid) ){
if( p->aAction[1]!=OE_None ) return 2;
eRet = 1;
}
}
}
}
return eRet;
}
/*
** This function is called when an UPDATE or DELETE operation is being
** compiled on table pTab, which is the parent table of foreign-key pFKey.
** If the current operation is an UPDATE, then the pChanges parameter is
** passed a pointer to the list of columns being modified. If it is a
** DELETE, pChanges is passed a NULL pointer.
**
** It returns a pointer to a Trigger structure containing a trigger
** equivalent to the ON UPDATE or ON DELETE action specified by pFKey.
** If the action is "NO ACTION" or "RESTRICT", then a NULL pointer is
** returned (these actions require no special handling by the triggers
** sub-system, code for them is created by fkScanChildren()).
**
** For example, if pFKey is the foreign key and pTab is table "p" in
** the following schema:
**
** CREATE TABLE p(pk PRIMARY KEY);
** CREATE TABLE c(ck REFERENCES p ON DELETE CASCADE);
**
** then the returned trigger structure is equivalent to:
**
** CREATE TRIGGER ... DELETE ON p BEGIN
** DELETE FROM c WHERE ck = old.pk;
** END;
**
** The returned pointer is cached as part of the foreign key object. It
** is eventually freed along with the rest of the foreign key object by
** sqlite3FkDelete().
*/
static Trigger *fkActionTrigger(
Parse *pParse, /* Parse context */
Table *pTab, /* Table being updated or deleted from */
FKey *pFKey, /* Foreign key to get action for */
ExprList *pChanges /* Change-list for UPDATE, NULL for DELETE */
){
sqlite3 *db = pParse->db; /* Database handle */
int action; /* One of OE_None, OE_Cascade etc. */
Trigger *pTrigger; /* Trigger definition to return */
int iAction = (pChanges!=0); /* 1 for UPDATE, 0 for DELETE */
action = pFKey->aAction[iAction];
if( action==OE_Restrict && (db->flags & SQLITE_DeferFKs) ){
return 0;
}
pTrigger = pFKey->apTrigger[iAction];
if( action!=OE_None && !pTrigger ){
char const *zFrom; /* Name of child table */
int nFrom; /* Length in bytes of zFrom */
Index *pIdx = 0; /* Parent key index for this FK */
int *aiCol = 0; /* child table cols -> parent key cols */
TriggerStep *pStep = 0; /* First (only) step of trigger program */
Expr *pWhere = 0; /* WHERE clause of trigger step */
ExprList *pList = 0; /* Changes list if ON UPDATE CASCADE */
Select *pSelect = 0; /* If RESTRICT, "SELECT RAISE(...)" */
int i; /* Iterator variable */
Expr *pWhen = 0; /* WHEN clause for the trigger */
if( sqlite3FkLocateIndex(pParse, pTab, pFKey, &pIdx, &aiCol) ) return 0;
assert( aiCol || pFKey->nCol==1 );
for(i=0; i<pFKey->nCol; i++){
Token tOld = { "old", 3 }; /* Literal "old" token */
Token tNew = { "new", 3 }; /* Literal "new" token */
Token tFromCol; /* Name of column in child table */
Token tToCol; /* Name of column in parent table */
int iFromCol; /* Idx of column in child table */
Expr *pEq; /* tFromCol = OLD.tToCol */
iFromCol = aiCol ? aiCol[i] : pFKey->aCol[0].iFrom;
assert( iFromCol>=0 );
assert( pIdx!=0 || (pTab->iPKey>=0 && pTab->iPKey<pTab->nCol) );
assert( pIdx==0 || pIdx->aiColumn[i]>=0 );
sqlite3TokenInit(&tToCol,
pTab->aCol[pIdx ? pIdx->aiColumn[i] : pTab->iPKey].zName);
sqlite3TokenInit(&tFromCol, pFKey->pFrom->aCol[iFromCol].zName);
/* Create the expression "OLD.zToCol = zFromCol". It is important
** that the "OLD.zToCol" term is on the LHS of the = operator, so
** that the affinity and collation sequence associated with the
** parent table are used for the comparison. */
pEq = sqlite3PExpr(pParse, TK_EQ,
sqlite3PExpr(pParse, TK_DOT,
sqlite3ExprAlloc(db, TK_ID, &tOld, 0),
sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)),
sqlite3ExprAlloc(db, TK_ID, &tFromCol, 0)
);
pWhere = sqlite3ExprAnd(pParse, pWhere, pEq);
/* For ON UPDATE, construct the next term of the WHEN clause.
** The final WHEN clause will be like this:
**
** WHEN NOT(old.col1 IS new.col1 AND ... AND old.colN IS new.colN)
*/
if( pChanges ){
pEq = sqlite3PExpr(pParse, TK_IS,
sqlite3PExpr(pParse, TK_DOT,
sqlite3ExprAlloc(db, TK_ID, &tOld, 0),
sqlite3ExprAlloc(db, TK_ID, &tToCol, 0)),
sqlite3PExpr(pParse, TK_DOT,
sqlite3ExprAlloc(db, TK_ID, &tNew, 0),
sqlite3ExprAlloc(db, TK_ID, &tToCol, 0))
);
pWhen = sqlite3ExprAnd(pParse, pWhen, pEq);
}
if( action!=OE_Restrict && (action!=OE_Cascade || pChanges) ){
Expr *pNew;
if( action==OE_Cascade ){
pNew = sqlite3PExpr(pParse, TK_DOT,
sqlite3ExprAlloc(db, TK_ID, &tNew, 0),
sqlite3ExprAlloc(db, TK_ID, &tToCol, 0));
}else if( action==OE_SetDflt ){
Column *pCol = pFKey->pFrom->aCol + iFromCol;
Expr *pDflt;
if( pCol->colFlags & COLFLAG_GENERATED ){
testcase( pCol->colFlags & COLFLAG_VIRTUAL );
testcase( pCol->colFlags & COLFLAG_STORED );
pDflt = 0;
}else{
pDflt = pCol->pDflt;
}
if( pDflt ){
pNew = sqlite3ExprDup(db, pDflt, 0);
}else{
pNew = sqlite3ExprAlloc(db, TK_NULL, 0, 0);
}
}else{
pNew = sqlite3ExprAlloc(db, TK_NULL, 0, 0);
}
pList = sqlite3ExprListAppend(pParse, pList, pNew);
sqlite3ExprListSetName(pParse, pList, &tFromCol, 0);
}
}
sqlite3DbFree(db, aiCol);
zFrom = pFKey->pFrom->zName;
nFrom = sqlite3Strlen30(zFrom);
if( action==OE_Restrict ){
Token tFrom;
Expr *pRaise;
tFrom.z = zFrom;
tFrom.n = nFrom;
pRaise = sqlite3Expr(db, TK_RAISE, "FOREIGN KEY constraint failed");
if( pRaise ){
pRaise->affExpr = OE_Abort;
}
pSelect = sqlite3SelectNew(pParse,
sqlite3ExprListAppend(pParse, 0, pRaise),
sqlite3SrcListAppend(pParse, 0, &tFrom, 0),
pWhere,
0, 0, 0, 0, 0
);
pWhere = 0;
}
/* Disable lookaside memory allocation */
DisableLookaside;
pTrigger = (Trigger *)sqlite3DbMallocZero(db,
sizeof(Trigger) + /* struct Trigger */
sizeof(TriggerStep) + /* Single step in trigger program */
nFrom + 1 /* Space for pStep->zTarget */
);
if( pTrigger ){
pStep = pTrigger->step_list = (TriggerStep *)&pTrigger[1];
pStep->zTarget = (char *)&pStep[1];
memcpy((char *)pStep->zTarget, zFrom, nFrom);
pStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
pStep->pExprList = sqlite3ExprListDup(db, pList, EXPRDUP_REDUCE);
pStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
if( pWhen ){
pWhen = sqlite3PExpr(pParse, TK_NOT, pWhen, 0);
pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
}
}
/* Re-enable the lookaside buffer, if it was disabled earlier. */
EnableLookaside;
sqlite3ExprDelete(db, pWhere);
sqlite3ExprDelete(db, pWhen);
sqlite3ExprListDelete(db, pList);
sqlite3SelectDelete(db, pSelect);
if( db->mallocFailed==1 ){
fkTriggerDelete(db, pTrigger);
return 0;
}
assert( pStep!=0 );
assert( pTrigger!=0 );
switch( action ){
case OE_Restrict:
pStep->op = TK_SELECT;
break;
case OE_Cascade:
if( !pChanges ){
pStep->op = TK_DELETE;
break;
}
/* no break */ deliberate_fall_through
default:
pStep->op = TK_UPDATE;
}
pStep->pTrig = pTrigger;
pTrigger->pSchema = pTab->pSchema;
pTrigger->pTabSchema = pTab->pSchema;
pFKey->apTrigger[iAction] = pTrigger;
pTrigger->op = (pChanges ? TK_UPDATE : TK_DELETE);
}
return pTrigger;
}
/*
** This function is called when deleting or updating a row to implement
** any required CASCADE, SET NULL or SET DEFAULT actions.
*/
SQLITE_PRIVATE void sqlite3FkActions(
Parse *pParse, /* Parse context */
Table *pTab, /* Table being updated or deleted from */
ExprList *pChanges, /* Change-list for UPDATE, NULL for DELETE */
int regOld, /* Address of array containing old row */
int *aChange, /* Array indicating UPDATEd columns (or 0) */
int bChngRowid /* True if rowid is UPDATEd */
){
/* If foreign-key support is enabled, iterate through all FKs that
** refer to table pTab. If there is an action associated with the FK
** for this operation (either update or delete), invoke the associated
** trigger sub-program. */
if( pParse->db->flags&SQLITE_ForeignKeys ){
FKey *pFKey; /* Iterator variable */
for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
if( aChange==0 || fkParentIsModified(pTab, pFKey, aChange, bChngRowid) ){
Trigger *pAct = fkActionTrigger(pParse, pTab, pFKey, pChanges);
if( pAct ){
sqlite3CodeRowTriggerDirect(pParse, pAct, pTab, regOld, OE_Abort, 0);
}
}
}
}
}
#endif /* ifndef SQLITE_OMIT_TRIGGER */
/*
** Free all memory associated with foreign key definitions attached to
** table pTab. Remove the deleted foreign keys from the Schema.fkeyHash
** hash table.
*/
SQLITE_PRIVATE void sqlite3FkDelete(sqlite3 *db, Table *pTab){
FKey *pFKey; /* Iterator variable */
FKey *pNext; /* Copy of pFKey->pNextFrom */
assert( db==0 || IsVirtual(pTab)
|| sqlite3SchemaMutexHeld(db, 0, pTab->pSchema) );
for(pFKey=pTab->pFKey; pFKey; pFKey=pNext){
/* Remove the FK from the fkeyHash hash table. */
if( !db || db->pnBytesFreed==0 ){
if( pFKey->pPrevTo ){
pFKey->pPrevTo->pNextTo = pFKey->pNextTo;
}else{
void *p = (void *)pFKey->pNextTo;
const char *z = (p ? pFKey->pNextTo->zTo : pFKey->zTo);
sqlite3HashInsert(&pTab->pSchema->fkeyHash, z, p);
}
if( pFKey->pNextTo ){
pFKey->pNextTo->pPrevTo = pFKey->pPrevTo;
}
}
/* EV: R-30323-21917 Each foreign key constraint in SQLite is
** classified as either immediate or deferred.
*/
assert( pFKey->isDeferred==0 || pFKey->isDeferred==1 );
/* Delete any triggers created to implement actions for this FK. */
#ifndef SQLITE_OMIT_TRIGGER
fkTriggerDelete(db, pFKey->apTrigger[0]);
fkTriggerDelete(db, pFKey->apTrigger[1]);
#endif
pNext = pFKey->pNextFrom;
sqlite3DbFree(db, pFKey);
}
}
#endif /* ifndef SQLITE_OMIT_FOREIGN_KEY */
/************** End of fkey.c ************************************************/
/************** Begin file insert.c ******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
*/
/* #include "sqliteInt.h" */
/*
** Generate code that will
**
** (1) acquire a lock for table pTab then
** (2) open pTab as cursor iCur.
**
** If pTab is a WITHOUT ROWID table, then it is the PRIMARY KEY index
** for that table that is actually opened.
*/
SQLITE_PRIVATE void sqlite3OpenTable(
Parse *pParse, /* Generate code into this VDBE */
int iCur, /* The cursor number of the table */
int iDb, /* The database index in sqlite3.aDb[] */
Table *pTab, /* The table to be opened */
int opcode /* OP_OpenRead or OP_OpenWrite */
){
Vdbe *v;
assert( !IsVirtual(pTab) );
assert( pParse->pVdbe!=0 );
v = pParse->pVdbe;
assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
sqlite3TableLock(pParse, iDb, pTab->tnum,
(opcode==OP_OpenWrite)?1:0, pTab->zName);
if( HasRowid(pTab) ){
sqlite3VdbeAddOp4Int(v, opcode, iCur, pTab->tnum, iDb, pTab->nNVCol);
VdbeComment((v, "%s", pTab->zName));
}else{
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
assert( pPk->tnum==pTab->tnum );
sqlite3VdbeAddOp3(v, opcode, iCur, pPk->tnum, iDb);
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
VdbeComment((v, "%s", pTab->zName));
}
}
/*
** Return a pointer to the column affinity string associated with index
** pIdx. A column affinity string has one character for each column in
** the table, according to the affinity of the column:
**
** Character Column affinity
** ------------------------------
** 'A' BLOB
** 'B' TEXT
** 'C' NUMERIC
** 'D' INTEGER
** 'F' REAL
**
** An extra 'D' is appended to the end of the string to cover the
** rowid that appears as the last column in every index.
**
** Memory for the buffer containing the column index affinity string
** is managed along with the rest of the Index structure. It will be
** released when sqlite3DeleteIndex() is called.
*/
SQLITE_PRIVATE const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
if( !pIdx->zColAff ){
/* The first time a column affinity string for a particular index is
** required, it is allocated and populated here. It is then stored as
** a member of the Index structure for subsequent use.
**
** The column affinity string will eventually be deleted by
** sqliteDeleteIndex() when the Index structure itself is cleaned
** up.
*/
int n;
Table *pTab = pIdx->pTable;
pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+1);
if( !pIdx->zColAff ){
sqlite3OomFault(db);
return 0;
}
for(n=0; n<pIdx->nColumn; n++){
i16 x = pIdx->aiColumn[n];
char aff;
if( x>=0 ){
aff = pTab->aCol[x].affinity;
}else if( x==XN_ROWID ){
aff = SQLITE_AFF_INTEGER;
}else{
assert( x==XN_EXPR );
assert( pIdx->aColExpr!=0 );
aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
}
if( aff<SQLITE_AFF_BLOB ) aff = SQLITE_AFF_BLOB;
if( aff>SQLITE_AFF_NUMERIC) aff = SQLITE_AFF_NUMERIC;
pIdx->zColAff[n] = aff;
}
pIdx->zColAff[n] = 0;
}
return pIdx->zColAff;
}
/*
** Compute the affinity string for table pTab, if it has not already been
** computed. As an optimization, omit trailing SQLITE_AFF_BLOB affinities.
**
** If the affinity exists (if it is no entirely SQLITE_AFF_BLOB values) and
** if iReg>0 then code an OP_Affinity opcode that will set the affinities
** for register iReg and following. Or if affinities exists and iReg==0,
** then just set the P4 operand of the previous opcode (which should be
** an OP_MakeRecord) to the affinity string.
**
** A column affinity string has one character per column:
**
** Character Column affinity
** ------------------------------
** 'A' BLOB
** 'B' TEXT
** 'C' NUMERIC
** 'D' INTEGER
** 'E' REAL
*/
SQLITE_PRIVATE void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
int i, j;
char *zColAff = pTab->zColAff;
if( zColAff==0 ){
sqlite3 *db = sqlite3VdbeDb(v);
zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
if( !zColAff ){
sqlite3OomFault(db);
return;
}
for(i=j=0; i<pTab->nCol; i++){
assert( pTab->aCol[i].affinity!=0 );
if( (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0 ){
zColAff[j++] = pTab->aCol[i].affinity;
}
}
do{
zColAff[j--] = 0;
}while( j>=0 && zColAff[j]<=SQLITE_AFF_BLOB );
pTab->zColAff = zColAff;
}
assert( zColAff!=0 );
i = sqlite3Strlen30NN(zColAff);
if( i ){
if( iReg ){
sqlite3VdbeAddOp4(v, OP_Affinity, iReg, i, 0, zColAff, i);
}else{
sqlite3VdbeChangeP4(v, -1, zColAff, i);
}
}
}
/*
** Return non-zero if the table pTab in database iDb or any of its indices
** have been opened at any point in the VDBE program. This is used to see if
** a statement of the form "INSERT INTO <iDb, pTab> SELECT ..." can
** run without using a temporary table for the results of the SELECT.
*/
static int readsTable(Parse *p, int iDb, Table *pTab){
Vdbe *v = sqlite3GetVdbe(p);
int i;
int iEnd = sqlite3VdbeCurrentAddr(v);
#ifndef SQLITE_OMIT_VIRTUALTABLE
VTable *pVTab = IsVirtual(pTab) ? sqlite3GetVTable(p->db, pTab) : 0;
#endif
for(i=1; i<iEnd; i++){
VdbeOp *pOp = sqlite3VdbeGetOp(v, i);
assert( pOp!=0 );
if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){
Index *pIndex;
Pgno tnum = pOp->p2;
if( tnum==pTab->tnum ){
return 1;
}
for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
if( tnum==pIndex->tnum ){
return 1;
}
}
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( pOp->opcode==OP_VOpen && pOp->p4.pVtab==pVTab ){
assert( pOp->p4.pVtab!=0 );
assert( pOp->p4type==P4_VTAB );
return 1;
}
#endif
}
return 0;
}
/* This walker callback will compute the union of colFlags flags for all
** referenced columns in a CHECK constraint or generated column expression.
*/
static int exprColumnFlagUnion(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_COLUMN && pExpr->iColumn>=0 ){
assert( pExpr->iColumn < pWalker->u.pTab->nCol );
pWalker->eCode |= pWalker->u.pTab->aCol[pExpr->iColumn].colFlags;
}
return WRC_Continue;
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/*
** All regular columns for table pTab have been puts into registers
** starting with iRegStore. The registers that correspond to STORED
** or VIRTUAL columns have not yet been initialized. This routine goes
** back and computes the values for those columns based on the previously
** computed normal columns.
*/
SQLITE_PRIVATE void sqlite3ComputeGeneratedColumns(
Parse *pParse, /* Parsing context */
int iRegStore, /* Register holding the first column */
Table *pTab /* The table */
){
int i;
Walker w;
Column *pRedo;
int eProgress;
VdbeOp *pOp;
assert( pTab->tabFlags & TF_HasGenerated );
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
/* Before computing generated columns, first go through and make sure
** that appropriate affinity has been applied to the regular columns
*/
sqlite3TableAffinity(pParse->pVdbe, pTab, iRegStore);
if( (pTab->tabFlags & TF_HasStored)!=0
&& (pOp = sqlite3VdbeGetOp(pParse->pVdbe,-1))->opcode==OP_Affinity
){
/* Change the OP_Affinity argument to '@' (NONE) for all stored
** columns. '@' is the no-op affinity and those columns have not
** yet been computed. */
int ii, jj;
char *zP4 = pOp->p4.z;
assert( zP4!=0 );
assert( pOp->p4type==P4_DYNAMIC );
for(ii=jj=0; zP4[jj]; ii++){
if( pTab->aCol[ii].colFlags & COLFLAG_VIRTUAL ){
continue;
}
if( pTab->aCol[ii].colFlags & COLFLAG_STORED ){
zP4[jj] = SQLITE_AFF_NONE;
}
jj++;
}
}
/* Because there can be multiple generated columns that refer to one another,
** this is a two-pass algorithm. On the first pass, mark all generated
** columns as "not available".
*/
for(i=0; i<pTab->nCol; i++){
if( pTab->aCol[i].colFlags & COLFLAG_GENERATED ){
testcase( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL );
testcase( pTab->aCol[i].colFlags & COLFLAG_STORED );
pTab->aCol[i].colFlags |= COLFLAG_NOTAVAIL;
}
}
w.u.pTab = pTab;
w.xExprCallback = exprColumnFlagUnion;
w.xSelectCallback = 0;
w.xSelectCallback2 = 0;
/* On the second pass, compute the value of each NOT-AVAILABLE column.
** Companion code in the TK_COLUMN case of sqlite3ExprCodeTarget() will
** compute dependencies and mark remove the COLSPAN_NOTAVAIL mark, as
** they are needed.
*/
pParse->iSelfTab = -iRegStore;
do{
eProgress = 0;
pRedo = 0;
for(i=0; i<pTab->nCol; i++){
Column *pCol = pTab->aCol + i;
if( (pCol->colFlags & COLFLAG_NOTAVAIL)!=0 ){
int x;
pCol->colFlags |= COLFLAG_BUSY;
w.eCode = 0;
sqlite3WalkExpr(&w, pCol->pDflt);
pCol->colFlags &= ~COLFLAG_BUSY;
if( w.eCode & COLFLAG_NOTAVAIL ){
pRedo = pCol;
continue;
}
eProgress = 1;
assert( pCol->colFlags & COLFLAG_GENERATED );
x = sqlite3TableColumnToStorage(pTab, i) + iRegStore;
sqlite3ExprCodeGeneratedColumn(pParse, pCol, x);
pCol->colFlags &= ~COLFLAG_NOTAVAIL;
}
}
}while( pRedo && eProgress );
if( pRedo ){
sqlite3ErrorMsg(pParse, "generated column loop on \"%s\"", pRedo->zName);
}
pParse->iSelfTab = 0;
}
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
#ifndef SQLITE_OMIT_AUTOINCREMENT
/*
** Locate or create an AutoincInfo structure associated with table pTab
** which is in database iDb. Return the register number for the register
** that holds the maximum rowid. Return zero if pTab is not an AUTOINCREMENT
** table. (Also return zero when doing a VACUUM since we do not want to
** update the AUTOINCREMENT counters during a VACUUM.)
**
** There is at most one AutoincInfo structure per table even if the
** same table is autoincremented multiple times due to inserts within
** triggers. A new AutoincInfo structure is created if this is the
** first use of table pTab. On 2nd and subsequent uses, the original
** AutoincInfo structure is used.
**
** Four consecutive registers are allocated:
**
** (1) The name of the pTab table.
** (2) The maximum ROWID of pTab.
** (3) The rowid in sqlite_sequence of pTab
** (4) The original value of the max ROWID in pTab, or NULL if none
**
** The 2nd register is the one that is returned. That is all the
** insert routine needs to know about.
*/
static int autoIncBegin(
Parse *pParse, /* Parsing context */
int iDb, /* Index of the database holding pTab */
Table *pTab /* The table we are writing to */
){
int memId = 0; /* Register holding maximum rowid */
assert( pParse->db->aDb[iDb].pSchema!=0 );
if( (pTab->tabFlags & TF_Autoincrement)!=0
&& (pParse->db->mDbFlags & DBFLAG_Vacuum)==0
){
Parse *pToplevel = sqlite3ParseToplevel(pParse);
AutoincInfo *pInfo;
Table *pSeqTab = pParse->db->aDb[iDb].pSchema->pSeqTab;
/* Verify that the sqlite_sequence table exists and is an ordinary
** rowid table with exactly two columns.
** Ticket d8dc2b3a58cd5dc2918a1d4acb 2018-05-23 */
if( pSeqTab==0
|| !HasRowid(pSeqTab)
|| IsVirtual(pSeqTab)
|| pSeqTab->nCol!=2
){
pParse->nErr++;
pParse->rc = SQLITE_CORRUPT_SEQUENCE;
return 0;
}
pInfo = pToplevel->pAinc;
while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
if( pInfo==0 ){
pInfo = sqlite3DbMallocRawNN(pParse->db, sizeof(*pInfo));
if( pInfo==0 ) return 0;
pInfo->pNext = pToplevel->pAinc;
pToplevel->pAinc = pInfo;
pInfo->pTab = pTab;
pInfo->iDb = iDb;
pToplevel->nMem++; /* Register to hold name of table */
pInfo->regCtr = ++pToplevel->nMem; /* Max rowid register */
pToplevel->nMem +=2; /* Rowid in sqlite_sequence + orig max val */
}
memId = pInfo->regCtr;
}
return memId;
}
/*
** This routine generates code that will initialize all of the
** register used by the autoincrement tracker.
*/
SQLITE_PRIVATE void sqlite3AutoincrementBegin(Parse *pParse){
AutoincInfo *p; /* Information about an AUTOINCREMENT */
sqlite3 *db = pParse->db; /* The database connection */
Db *pDb; /* Database only autoinc table */
int memId; /* Register holding max rowid */
Vdbe *v = pParse->pVdbe; /* VDBE under construction */
/* This routine is never called during trigger-generation. It is
** only called from the top-level */
assert( pParse->pTriggerTab==0 );
assert( sqlite3IsToplevel(pParse) );
assert( v ); /* We failed long ago if this is not so */
for(p = pParse->pAinc; p; p = p->pNext){
static const int iLn = VDBE_OFFSET_LINENO(2);
static const VdbeOpList autoInc[] = {
/* 0 */ {OP_Null, 0, 0, 0},
/* 1 */ {OP_Rewind, 0, 10, 0},
/* 2 */ {OP_Column, 0, 0, 0},
/* 3 */ {OP_Ne, 0, 9, 0},
/* 4 */ {OP_Rowid, 0, 0, 0},
/* 5 */ {OP_Column, 0, 1, 0},
/* 6 */ {OP_AddImm, 0, 0, 0},
/* 7 */ {OP_Copy, 0, 0, 0},
/* 8 */ {OP_Goto, 0, 11, 0},
/* 9 */ {OP_Next, 0, 2, 0},
/* 10 */ {OP_Integer, 0, 0, 0},
/* 11 */ {OP_Close, 0, 0, 0}
};
VdbeOp *aOp;
pDb = &db->aDb[p->iDb];
memId = p->regCtr;
assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
sqlite3VdbeLoadString(v, memId-1, p->pTab->zName);
aOp = sqlite3VdbeAddOpList(v, ArraySize(autoInc), autoInc, iLn);
if( aOp==0 ) break;
aOp[0].p2 = memId;
aOp[0].p3 = memId+2;
aOp[2].p3 = memId;
aOp[3].p1 = memId-1;
aOp[3].p3 = memId;
aOp[3].p5 = SQLITE_JUMPIFNULL;
aOp[4].p2 = memId+1;
aOp[5].p3 = memId;
aOp[6].p1 = memId;
aOp[7].p2 = memId+2;
aOp[7].p1 = memId;
aOp[10].p2 = memId;
if( pParse->nTab==0 ) pParse->nTab = 1;
}
}
/*
** Update the maximum rowid for an autoincrement calculation.
**
** This routine should be called when the regRowid register holds a
** new rowid that is about to be inserted. If that new rowid is
** larger than the maximum rowid in the memId memory cell, then the
** memory cell is updated.
*/
static void autoIncStep(Parse *pParse, int memId, int regRowid){
if( memId>0 ){
sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);
}
}
/*
** This routine generates the code needed to write autoincrement
** maximum rowid values back into the sqlite_sequence register.
** Every statement that might do an INSERT into an autoincrement
** table (either directly or through triggers) needs to call this
** routine just before the "exit" code.
*/
static SQLITE_NOINLINE void autoIncrementEnd(Parse *pParse){
AutoincInfo *p;
Vdbe *v = pParse->pVdbe;
sqlite3 *db = pParse->db;
assert( v );
for(p = pParse->pAinc; p; p = p->pNext){
static const int iLn = VDBE_OFFSET_LINENO(2);
static const VdbeOpList autoIncEnd[] = {
/* 0 */ {OP_NotNull, 0, 2, 0},
/* 1 */ {OP_NewRowid, 0, 0, 0},
/* 2 */ {OP_MakeRecord, 0, 2, 0},
/* 3 */ {OP_Insert, 0, 0, 0},
/* 4 */ {OP_Close, 0, 0, 0}
};
VdbeOp *aOp;
Db *pDb = &db->aDb[p->iDb];
int iRec;
int memId = p->regCtr;
iRec = sqlite3GetTempReg(pParse);
assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
sqlite3VdbeAddOp3(v, OP_Le, memId+2, sqlite3VdbeCurrentAddr(v)+7, memId);
VdbeCoverage(v);
sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
aOp = sqlite3VdbeAddOpList(v, ArraySize(autoIncEnd), autoIncEnd, iLn);
if( aOp==0 ) break;
aOp[0].p1 = memId+1;
aOp[1].p2 = memId+1;
aOp[2].p1 = memId-1;
aOp[2].p3 = iRec;
aOp[3].p2 = iRec;
aOp[3].p3 = memId+1;
aOp[3].p5 = OPFLAG_APPEND;
sqlite3ReleaseTempReg(pParse, iRec);
}
}
SQLITE_PRIVATE void sqlite3AutoincrementEnd(Parse *pParse){
if( pParse->pAinc ) autoIncrementEnd(pParse);
}
#else
/*
** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
** above are all no-ops
*/
# define autoIncBegin(A,B,C) (0)
# define autoIncStep(A,B,C)
#endif /* SQLITE_OMIT_AUTOINCREMENT */
/* Forward declaration */
static int xferOptimization(
Parse *pParse, /* Parser context */
Table *pDest, /* The table we are inserting into */
Select *pSelect, /* A SELECT statement to use as the data source */
int onError, /* How to handle constraint errors */
int iDbDest /* The database of pDest */
);
/*
** This routine is called to handle SQL of the following forms:
**
** insert into TABLE (IDLIST) values(EXPRLIST),(EXPRLIST),...
** insert into TABLE (IDLIST) select
** insert into TABLE (IDLIST) default values
**
** The IDLIST following the table name is always optional. If omitted,
** then a list of all (non-hidden) columns for the table is substituted.
** The IDLIST appears in the pColumn parameter. pColumn is NULL if IDLIST
** is omitted.
**
** For the pSelect parameter holds the values to be inserted for the
** first two forms shown above. A VALUES clause is really just short-hand
** for a SELECT statement that omits the FROM clause and everything else
** that follows. If the pSelect parameter is NULL, that means that the
** DEFAULT VALUES form of the INSERT statement is intended.
**
** The code generated follows one of four templates. For a simple
** insert with data coming from a single-row VALUES clause, the code executes
** once straight down through. Pseudo-code follows (we call this
** the "1st template"):
**
** open write cursor to <table> and its indices
** put VALUES clause expressions into registers
** write the resulting record into <table>
** cleanup
**
** The three remaining templates assume the statement is of the form
**
** INSERT INTO <table> SELECT ...
**
** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
** in other words if the SELECT pulls all columns from a single table
** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
** if <table2> and <table1> are distinct tables but have identical
** schemas, including all the same indices, then a special optimization
** is invoked that copies raw records from <table2> over to <table1>.
** See the xferOptimization() function for the implementation of this
** template. This is the 2nd template.
**
** open a write cursor to <table>
** open read cursor on <table2>
** transfer all records in <table2> over to <table>
** close cursors
** foreach index on <table>
** open a write cursor on the <table> index
** open a read cursor on the corresponding <table2> index
** transfer all records from the read to the write cursors
** close cursors
** end foreach
**
** The 3rd template is for when the second template does not apply
** and the SELECT clause does not read from <table> at any time.
** The generated code follows this template:
**
** X <- A
** goto B
** A: setup for the SELECT
** loop over the rows in the SELECT
** load values into registers R..R+n
** yield X
** end loop
** cleanup after the SELECT
** end-coroutine X
** B: open write cursor to <table> and its indices
** C: yield X, at EOF goto D
** insert the select result into <table> from R..R+n
** goto C
** D: cleanup
**
** The 4th template is used if the insert statement takes its
** values from a SELECT but the data is being inserted into a table
** that is also read as part of the SELECT. In the third form,
** we have to use an intermediate table to store the results of
** the select. The template is like this:
**
** X <- A
** goto B
** A: setup for the SELECT
** loop over the tables in the SELECT
** load value into register R..R+n
** yield X
** end loop
** cleanup after the SELECT
** end co-routine R
** B: open temp table
** L: yield X, at EOF goto M
** insert row from R..R+n into temp table
** goto L
** M: open write cursor to <table> and its indices
** rewind temp table
** C: loop over rows of intermediate table
** transfer values form intermediate table into <table>
** end loop
** D: cleanup
*/
SQLITE_PRIVATE void sqlite3Insert(
Parse *pParse, /* Parser context */
SrcList *pTabList, /* Name of table into which we are inserting */
Select *pSelect, /* A SELECT statement to use as the data source */
IdList *pColumn, /* Column names corresponding to IDLIST, or NULL. */
int onError, /* How to handle constraint errors */
Upsert *pUpsert /* ON CONFLICT clauses for upsert, or NULL */
){
sqlite3 *db; /* The main database structure */
Table *pTab; /* The table to insert into. aka TABLE */
int i, j; /* Loop counters */
Vdbe *v; /* Generate code into this virtual machine */
Index *pIdx; /* For looping over indices of the table */
int nColumn; /* Number of columns in the data */
int nHidden = 0; /* Number of hidden columns if TABLE is virtual */
int iDataCur = 0; /* VDBE cursor that is the main data repository */
int iIdxCur = 0; /* First index cursor */
int ipkColumn = -1; /* Column that is the INTEGER PRIMARY KEY */
int endOfLoop; /* Label for the end of the insertion loop */
int srcTab = 0; /* Data comes from this temporary cursor if >=0 */
int addrInsTop = 0; /* Jump to label "D" */
int addrCont = 0; /* Top of insert loop. Label "C" in templates 3 and 4 */
SelectDest dest; /* Destination for SELECT on rhs of INSERT */
int iDb; /* Index of database holding TABLE */
u8 useTempTable = 0; /* Store SELECT results in intermediate table */
u8 appendFlag = 0; /* True if the insert is likely to be an append */
u8 withoutRowid; /* 0 for normal table. 1 for WITHOUT ROWID table */
u8 bIdListInOrder; /* True if IDLIST is in table order */
ExprList *pList = 0; /* List of VALUES() to be inserted */
int iRegStore; /* Register in which to store next column */
/* Register allocations */
int regFromSelect = 0;/* Base register for data coming from SELECT */
int regAutoinc = 0; /* Register holding the AUTOINCREMENT counter */
int regRowCount = 0; /* Memory cell used for the row counter */
int regIns; /* Block of regs holding rowid+data being inserted */
int regRowid; /* registers holding insert rowid */
int regData; /* register holding first column to insert */
int *aRegIdx = 0; /* One register allocated to each index */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True if attempting to insert into a view */
Trigger *pTrigger; /* List of triggers on pTab, if required */
int tmask; /* Mask of trigger times */
#endif
db = pParse->db;
if( pParse->nErr || db->mallocFailed ){
goto insert_cleanup;
}
dest.iSDParm = 0; /* Suppress a harmless compiler warning */
/* If the Select object is really just a simple VALUES() list with a
** single row (the common case) then keep that one row of values
** and discard the other (unused) parts of the pSelect object
*/
if( pSelect && (pSelect->selFlags & SF_Values)!=0 && pSelect->pPrior==0 ){
pList = pSelect->pEList;
pSelect->pEList = 0;
sqlite3SelectDelete(db, pSelect);
pSelect = 0;
}
/* Locate the table into which we will be inserting new information.
*/
assert( pTabList->nSrc==1 );
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ){
goto insert_cleanup;
}
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
assert( iDb<db->nDb );
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0,
db->aDb[iDb].zDbSName) ){
goto insert_cleanup;
}
withoutRowid = !HasRowid(pTab);
/* Figure out if we have any triggers and if the table being
** inserted into is a view
*/
#ifndef SQLITE_OMIT_TRIGGER
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0, &tmask);
isView = pTab->pSelect!=0;
#else
# define pTrigger 0
# define tmask 0
# define isView 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );
/* If pTab is really a view, make sure it has been initialized.
** ViewGetColumnNames() is a no-op if pTab is not a view.
*/
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto insert_cleanup;
}
/* Cannot insert into a read-only table.
*/
if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
goto insert_cleanup;
}
/* Allocate a VDBE
*/
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto insert_cleanup;
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, pSelect || pTrigger, iDb);
#ifndef SQLITE_OMIT_XFER_OPT
/* If the statement is of the form
**
** INSERT INTO <table1> SELECT * FROM <table2>;
**
** Then special optimizations can be applied that make the transfer
** very fast and which reduce fragmentation of indices.
**
** This is the 2nd template.
*/
if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
assert( !pTrigger );
assert( pList==0 );
goto insert_end;
}
#endif /* SQLITE_OMIT_XFER_OPT */
/* If this is an AUTOINCREMENT table, look up the sequence number in the
** sqlite_sequence table and store it in memory cell regAutoinc.
*/
regAutoinc = autoIncBegin(pParse, iDb, pTab);
/* Allocate a block registers to hold the rowid and the values
** for all columns of the new row.
*/
regRowid = regIns = pParse->nMem+1;
pParse->nMem += pTab->nCol + 1;
if( IsVirtual(pTab) ){
regRowid++;
pParse->nMem++;
}
regData = regRowid+1;
/* If the INSERT statement included an IDLIST term, then make sure
** all elements of the IDLIST really are columns of the table and
** remember the column indices.
**
** If the table has an INTEGER PRIMARY KEY column and that column
** is named in the IDLIST, then record in the ipkColumn variable
** the index into IDLIST of the primary key column. ipkColumn is
** the index of the primary key as it appears in IDLIST, not as
** is appears in the original table. (The index of the INTEGER
** PRIMARY KEY in the original table is pTab->iPKey.) After this
** loop, if ipkColumn==(-1), that means that integer primary key
** is unspecified, and hence the table is either WITHOUT ROWID or
** it will automatically generated an integer primary key.
**
** bIdListInOrder is true if the columns in IDLIST are in storage
** order. This enables an optimization that avoids shuffling the
** columns into storage order. False negatives are harmless,
** but false positives will cause database corruption.
*/
bIdListInOrder = (pTab->tabFlags & (TF_OOOHidden|TF_HasStored))==0;
if( pColumn ){
for(i=0; i<pColumn->nId; i++){
pColumn->a[i].idx = -1;
}
for(i=0; i<pColumn->nId; i++){
for(j=0; j<pTab->nCol; j++){
if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
pColumn->a[i].idx = j;
if( i!=j ) bIdListInOrder = 0;
if( j==pTab->iPKey ){
ipkColumn = i; assert( !withoutRowid );
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( pTab->aCol[j].colFlags & (COLFLAG_STORED|COLFLAG_VIRTUAL) ){
sqlite3ErrorMsg(pParse,
"cannot INSERT into generated column \"%s\"",
pTab->aCol[j].zName);
goto insert_cleanup;
}
#endif
break;
}
}
if( j>=pTab->nCol ){
if( sqlite3IsRowid(pColumn->a[i].zName) && !withoutRowid ){
ipkColumn = i;
bIdListInOrder = 0;
}else{
sqlite3ErrorMsg(pParse, "table %S has no column named %s",
pTabList, 0, pColumn->a[i].zName);
pParse->checkSchema = 1;
goto insert_cleanup;
}
}
}
}
/* Figure out how many columns of data are supplied. If the data
** is coming from a SELECT statement, then generate a co-routine that
** produces a single row of the SELECT on each invocation. The
** co-routine is the common header to the 3rd and 4th templates.
*/
if( pSelect ){
/* Data is coming from a SELECT or from a multi-row VALUES clause.
** Generate a co-routine to run the SELECT. */
int regYield; /* Register holding co-routine entry-point */
int addrTop; /* Top of the co-routine */
int rc; /* Result code */
regYield = ++pParse->nMem;
addrTop = sqlite3VdbeCurrentAddr(v) + 1;
sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, addrTop);
sqlite3SelectDestInit(&dest, SRT_Coroutine, regYield);
dest.iSdst = bIdListInOrder ? regData : 0;
dest.nSdst = pTab->nCol;
rc = sqlite3Select(pParse, pSelect, &dest);
regFromSelect = dest.iSdst;
if( rc || db->mallocFailed || pParse->nErr ) goto insert_cleanup;
sqlite3VdbeEndCoroutine(v, regYield);
sqlite3VdbeJumpHere(v, addrTop - 1); /* label B: */
assert( pSelect->pEList );
nColumn = pSelect->pEList->nExpr;
/* Set useTempTable to TRUE if the result of the SELECT statement
** should be written into a temporary table (template 4). Set to
** FALSE if each output row of the SELECT can be written directly into
** the destination table (template 3).
**
** A temp table must be used if the table being updated is also one
** of the tables being read by the SELECT statement. Also use a
** temp table in the case of row triggers.
*/
if( pTrigger || readsTable(pParse, iDb, pTab) ){
useTempTable = 1;
}
if( useTempTable ){
/* Invoke the coroutine to extract information from the SELECT
** and add it to a transient table srcTab. The code generated
** here is from the 4th template:
**
** B: open temp table
** L: yield X, goto M at EOF
** insert row from R..R+n into temp table
** goto L
** M: ...
*/
int regRec; /* Register to hold packed record */
int regTempRowid; /* Register to hold temp table ROWID */
int addrL; /* Label "L" */
srcTab = pParse->nTab++;
regRec = sqlite3GetTempReg(pParse);
regTempRowid = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
addrL = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm); VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
sqlite3VdbeGoto(v, addrL);
sqlite3VdbeJumpHere(v, addrL);
sqlite3ReleaseTempReg(pParse, regRec);
sqlite3ReleaseTempReg(pParse, regTempRowid);
}
}else{
/* This is the case if the data for the INSERT is coming from a
** single-row VALUES clause
*/
NameContext sNC;
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
srcTab = -1;
assert( useTempTable==0 );
if( pList ){
nColumn = pList->nExpr;
if( sqlite3ResolveExprListNames(&sNC, pList) ){
goto insert_cleanup;
}
}else{
nColumn = 0;
}
}
/* If there is no IDLIST term but the table has an integer primary
** key, the set the ipkColumn variable to the integer primary key
** column index in the original table definition.
*/
if( pColumn==0 && nColumn>0 ){
ipkColumn = pTab->iPKey;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( ipkColumn>=0 && (pTab->tabFlags & TF_HasGenerated)!=0 ){
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
for(i=ipkColumn-1; i>=0; i--){
if( pTab->aCol[i].colFlags & COLFLAG_GENERATED ){
testcase( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL );
testcase( pTab->aCol[i].colFlags & COLFLAG_STORED );
ipkColumn--;
}
}
}
#endif
}
/* Make sure the number of columns in the source data matches the number
** of columns to be inserted into the table.
*/
for(i=0; i<pTab->nCol; i++){
if( pTab->aCol[i].colFlags & COLFLAG_NOINSERT ) nHidden++;
}
if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){
sqlite3ErrorMsg(pParse,
"table %S has %d columns but %d values were supplied",
pTabList, 0, pTab->nCol-nHidden, nColumn);
goto insert_cleanup;
}
if( pColumn!=0 && nColumn!=pColumn->nId ){
sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
goto insert_cleanup;
}
/* Initialize the count of rows to be inserted
*/
if( (db->flags & SQLITE_CountRows)!=0
&& !pParse->nested
&& !pParse->pTriggerTab
){
regRowCount = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
}
/* If this is not a view, open the table and and all indices */
if( !isView ){
int nIdx;
nIdx = sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, -1, 0,
&iDataCur, &iIdxCur);
aRegIdx = sqlite3DbMallocRawNN(db, sizeof(int)*(nIdx+2));
if( aRegIdx==0 ){
goto insert_cleanup;
}
for(i=0, pIdx=pTab->pIndex; i<nIdx; pIdx=pIdx->pNext, i++){
assert( pIdx );
aRegIdx[i] = ++pParse->nMem;
pParse->nMem += pIdx->nColumn;
}
aRegIdx[i] = ++pParse->nMem; /* Register to store the table record */
}
#ifndef SQLITE_OMIT_UPSERT
if( pUpsert ){
if( IsVirtual(pTab) ){
sqlite3ErrorMsg(pParse, "UPSERT not implemented for virtual table \"%s\"",
pTab->zName);
goto insert_cleanup;
}
if( pTab->pSelect ){
sqlite3ErrorMsg(pParse, "cannot UPSERT a view");
goto insert_cleanup;
}
if( sqlite3HasExplicitNulls(pParse, pUpsert->pUpsertTarget) ){
goto insert_cleanup;
}
pTabList->a[0].iCursor = iDataCur;
pUpsert->pUpsertSrc = pTabList;
pUpsert->regData = regData;
pUpsert->iDataCur = iDataCur;
pUpsert->iIdxCur = iIdxCur;
if( pUpsert->pUpsertTarget ){
sqlite3UpsertAnalyzeTarget(pParse, pTabList, pUpsert);
}
}
#endif
/* This is the top of the main insertion loop */
if( useTempTable ){
/* This block codes the top of loop only. The complete loop is the
** following pseudocode (template 4):
**
** rewind temp table, if empty goto D
** C: loop over rows of intermediate table
** transfer values form intermediate table into <table>
** end loop
** D: ...
*/
addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab); VdbeCoverage(v);
addrCont = sqlite3VdbeCurrentAddr(v);
}else if( pSelect ){
/* This block codes the top of loop only. The complete loop is the
** following pseudocode (template 3):
**
** C: yield X, at EOF goto D
** insert the select result into <table> from R..R+n
** goto C
** D: ...
*/
sqlite3VdbeReleaseRegisters(pParse, regData, pTab->nCol, 0, 0);
addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
VdbeCoverage(v);
if( ipkColumn>=0 ){
/* tag-20191021-001: If the INTEGER PRIMARY KEY is being generated by the
** SELECT, go ahead and copy the value into the rowid slot now, so that
** the value does not get overwritten by a NULL at tag-20191021-002. */
sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
}
}
/* Compute data for ordinary columns of the new entry. Values
** are written in storage order into registers starting with regData.
** Only ordinary columns are computed in this loop. The rowid
** (if there is one) is computed later and generated columns are
** computed after the rowid since they might depend on the value
** of the rowid.
*/
nHidden = 0;
iRegStore = regData; assert( regData==regRowid+1 );
for(i=0; i<pTab->nCol; i++, iRegStore++){
int k;
u32 colFlags;
assert( i>=nHidden );
if( i==pTab->iPKey ){
/* tag-20191021-002: References to the INTEGER PRIMARY KEY are filled
** using the rowid. So put a NULL in the IPK slot of the record to avoid
** using excess space. The file format definition requires this extra
** NULL - we cannot optimize further by skipping the column completely */
sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
continue;
}
if( ((colFlags = pTab->aCol[i].colFlags) & COLFLAG_NOINSERT)!=0 ){
nHidden++;
if( (colFlags & COLFLAG_VIRTUAL)!=0 ){
/* Virtual columns do not participate in OP_MakeRecord. So back up
** iRegStore by one slot to compensate for the iRegStore++ in the
** outer for() loop */
iRegStore--;
continue;
}else if( (colFlags & COLFLAG_STORED)!=0 ){
/* Stored columns are computed later. But if there are BEFORE
** triggers, the slots used for stored columns will be OP_Copy-ed
** to a second block of registers, so the register needs to be
** initialized to NULL to avoid an uninitialized register read */
if( tmask & TRIGGER_BEFORE ){
sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
}
continue;
}else if( pColumn==0 ){
/* Hidden columns that are not explicitly named in the INSERT
** get there default value */
sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
continue;
}
}
if( pColumn ){
for(j=0; j<pColumn->nId && pColumn->a[j].idx!=i; j++){}
if( j>=pColumn->nId ){
/* A column not named in the insert column list gets its
** default value */
sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
continue;
}
k = j;
}else if( nColumn==0 ){
/* This is INSERT INTO ... DEFAULT VALUES. Load the default value. */
sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
continue;
}else{
k = i - nHidden;
}
if( useTempTable ){
sqlite3VdbeAddOp3(v, OP_Column, srcTab, k, iRegStore);
}else if( pSelect ){
if( regFromSelect!=regData ){
sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+k, iRegStore);
}
}else{
sqlite3ExprCode(pParse, pList->a[k].pExpr, iRegStore);
}
}
/* Run the BEFORE and INSTEAD OF triggers, if there are any
*/
endOfLoop = sqlite3VdbeMakeLabel(pParse);
if( tmask & TRIGGER_BEFORE ){
int regCols = sqlite3GetTempRange(pParse, pTab->nCol+1);
/* build the NEW.* reference row. Note that if there is an INTEGER
** PRIMARY KEY into which a NULL is being inserted, that NULL will be
** translated into a unique ID for the row. But on a BEFORE trigger,
** we do not know what the unique ID will be (because the insert has
** not happened yet) so we substitute a rowid of -1
*/
if( ipkColumn<0 ){
sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
}else{
int addr1;
assert( !withoutRowid );
if( useTempTable ){
sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regCols);
}else{
assert( pSelect==0 ); /* Otherwise useTempTable is true */
sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regCols);
}
addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols); VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
sqlite3VdbeJumpHere(v, addr1);
sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols); VdbeCoverage(v);
}
/* Cannot have triggers on a virtual table. If it were possible,
** this block would have to account for hidden column.
*/
assert( !IsVirtual(pTab) );
/* Copy the new data already generated. */
assert( pTab->nNVCol>0 );
sqlite3VdbeAddOp3(v, OP_Copy, regRowid+1, regCols+1, pTab->nNVCol-1);
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* Compute the new value for generated columns after all other
** columns have already been computed. This must be done after
** computing the ROWID in case one of the generated columns
** refers to the ROWID. */
if( pTab->tabFlags & TF_HasGenerated ){
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
sqlite3ComputeGeneratedColumns(pParse, regCols+1, pTab);
}
#endif
/* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
** do not attempt any conversions before assembling the record.
** If this is a real table, attempt conversions as required by the
** table column affinities.
*/
if( !isView ){
sqlite3TableAffinity(v, pTab, regCols+1);
}
/* Fire BEFORE or INSTEAD OF triggers */
sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_BEFORE,
pTab, regCols-pTab->nCol-1, onError, endOfLoop);
sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);
}
if( !isView ){
if( IsVirtual(pTab) ){
/* The row that the VUpdate opcode will delete: none */
sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
}
if( ipkColumn>=0 ){
/* Compute the new rowid */
if( useTempTable ){
sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);
}else if( pSelect ){
/* Rowid already initialized at tag-20191021-001 */
}else{
Expr *pIpk = pList->a[ipkColumn].pExpr;
if( pIpk->op==TK_NULL && !IsVirtual(pTab) ){
sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
appendFlag = 1;
}else{
sqlite3ExprCode(pParse, pList->a[ipkColumn].pExpr, regRowid);
}
}
/* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
** to generate a unique primary key value.
*/
if( !appendFlag ){
int addr1;
if( !IsVirtual(pTab) ){
addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid); VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
sqlite3VdbeJumpHere(v, addr1);
}else{
addr1 = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, addr1+2); VdbeCoverage(v);
}
sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid); VdbeCoverage(v);
}
}else if( IsVirtual(pTab) || withoutRowid ){
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
}else{
sqlite3VdbeAddOp3(v, OP_NewRowid, iDataCur, regRowid, regAutoinc);
appendFlag = 1;
}
autoIncStep(pParse, regAutoinc, regRowid);
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* Compute the new value for generated columns after all other
** columns have already been computed. This must be done after
** computing the ROWID in case one of the generated columns
** is derived from the INTEGER PRIMARY KEY. */
if( pTab->tabFlags & TF_HasGenerated ){
sqlite3ComputeGeneratedColumns(pParse, regRowid+1, pTab);
}
#endif
/* Generate code to check constraints and generate index keys and
** do the insertion.
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab) ){
const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
sqlite3VtabMakeWritable(pParse, pTab);
sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
sqlite3MayAbort(pParse);
}else
#endif
{
int isReplace; /* Set to true if constraints may cause a replace */
int bUseSeek; /* True to use OPFLAG_SEEKRESULT */
sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace, 0, pUpsert
);
sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
/* Set the OPFLAG_USESEEKRESULT flag if either (a) there are no REPLACE
** constraints or (b) there are no triggers and this table is not a
** parent table in a foreign key constraint. It is safe to set the
** flag in the second case as if any REPLACE constraint is hit, an
** OP_Delete or OP_IdxDelete instruction will be executed on each
** cursor that is disturbed. And these instructions both clear the
** VdbeCursor.seekResult variable, disabling the OPFLAG_USESEEKRESULT
** functionality. */
bUseSeek = (isReplace==0 || !sqlite3VdbeHasSubProgram(v));
sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
regIns, aRegIdx, 0, appendFlag, bUseSeek
);
}
}
/* Update the count of rows that are inserted
*/
if( regRowCount ){
sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
}
if( pTrigger ){
/* Code AFTER triggers */
sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_AFTER,
pTab, regData-2-pTab->nCol, onError, endOfLoop);
}
/* The bottom of the main insertion loop, if the data source
** is a SELECT statement.
*/
sqlite3VdbeResolveLabel(v, endOfLoop);
if( useTempTable ){
sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addrInsTop);
sqlite3VdbeAddOp1(v, OP_Close, srcTab);
}else if( pSelect ){
sqlite3VdbeGoto(v, addrCont);
#ifdef SQLITE_DEBUG
/* If we are jumping back to an OP_Yield that is preceded by an
** OP_ReleaseReg, set the p5 flag on the OP_Goto so that the
** OP_ReleaseReg will be included in the loop. */
if( sqlite3VdbeGetOp(v, addrCont-1)->opcode==OP_ReleaseReg ){
assert( sqlite3VdbeGetOp(v, addrCont)->opcode==OP_Yield );
sqlite3VdbeChangeP5(v, 1);
}
#endif
sqlite3VdbeJumpHere(v, addrInsTop);
}
insert_end:
/* Update the sqlite_sequence table by storing the content of the
** maximum rowid counter values recorded while inserting into
** autoincrement tables.
*/
if( pParse->nested==0 && pParse->pTriggerTab==0 ){
sqlite3AutoincrementEnd(pParse);
}
/*
** Return the number of rows inserted. If this routine is
** generating code because of a call to sqlite3NestedParse(), do not
** invoke the callback function.
*/
if( regRowCount ){
sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", SQLITE_STATIC);
}
insert_cleanup:
sqlite3SrcListDelete(db, pTabList);
sqlite3ExprListDelete(db, pList);
sqlite3UpsertDelete(db, pUpsert);
sqlite3SelectDelete(db, pSelect);
sqlite3IdListDelete(db, pColumn);
sqlite3DbFree(db, aRegIdx);
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation). */
#ifdef isView
#undef isView
#endif
#ifdef pTrigger
#undef pTrigger
#endif
#ifdef tmask
#undef tmask
#endif
/*
** Meanings of bits in of pWalker->eCode for
** sqlite3ExprReferencesUpdatedColumn()
*/
#define CKCNSTRNT_COLUMN 0x01 /* CHECK constraint uses a changing column */
#define CKCNSTRNT_ROWID 0x02 /* CHECK constraint references the ROWID */
/* This is the Walker callback from sqlite3ExprReferencesUpdatedColumn().
* Set bit 0x01 of pWalker->eCode if pWalker->eCode to 0 and if this
** expression node references any of the
** columns that are being modifed by an UPDATE statement.
*/
static int checkConstraintExprNode(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_COLUMN ){
assert( pExpr->iColumn>=0 || pExpr->iColumn==-1 );
if( pExpr->iColumn>=0 ){
if( pWalker->u.aiCol[pExpr->iColumn]>=0 ){
pWalker->eCode |= CKCNSTRNT_COLUMN;
}
}else{
pWalker->eCode |= CKCNSTRNT_ROWID;
}
}
return WRC_Continue;
}
/*
** pExpr is a CHECK constraint on a row that is being UPDATE-ed. The
** only columns that are modified by the UPDATE are those for which
** aiChng[i]>=0, and also the ROWID is modified if chngRowid is true.
**
** Return true if CHECK constraint pExpr uses any of the
** changing columns (or the rowid if it is changing). In other words,
** return true if this CHECK constraint must be validated for
** the new row in the UPDATE statement.
**
** 2018-09-15: pExpr might also be an expression for an index-on-expressions.
** The operation of this routine is the same - return true if an only if
** the expression uses one or more of columns identified by the second and
** third arguments.
*/
SQLITE_PRIVATE int sqlite3ExprReferencesUpdatedColumn(
Expr *pExpr, /* The expression to be checked */
int *aiChng, /* aiChng[x]>=0 if column x changed by the UPDATE */
int chngRowid /* True if UPDATE changes the rowid */
){
Walker w;
memset(&w, 0, sizeof(w));
w.eCode = 0;
w.xExprCallback = checkConstraintExprNode;
w.u.aiCol = aiChng;
sqlite3WalkExpr(&w, pExpr);
if( !chngRowid ){
testcase( (w.eCode & CKCNSTRNT_ROWID)!=0 );
w.eCode &= ~CKCNSTRNT_ROWID;
}
testcase( w.eCode==0 );
testcase( w.eCode==CKCNSTRNT_COLUMN );
testcase( w.eCode==CKCNSTRNT_ROWID );
testcase( w.eCode==(CKCNSTRNT_ROWID|CKCNSTRNT_COLUMN) );
return w.eCode!=0;
}
/*
** Generate code to do constraint checks prior to an INSERT or an UPDATE
** on table pTab.
**
** The regNewData parameter is the first register in a range that contains
** the data to be inserted or the data after the update. There will be
** pTab->nCol+1 registers in this range. The first register (the one
** that regNewData points to) will contain the new rowid, or NULL in the
** case of a WITHOUT ROWID table. The second register in the range will
** contain the content of the first table column. The third register will
** contain the content of the second table column. And so forth.
**
** The regOldData parameter is similar to regNewData except that it contains
** the data prior to an UPDATE rather than afterwards. regOldData is zero
** for an INSERT. This routine can distinguish between UPDATE and INSERT by
** checking regOldData for zero.
**
** For an UPDATE, the pkChng boolean is true if the true primary key (the
** rowid for a normal table or the PRIMARY KEY for a WITHOUT ROWID table)
** might be modified by the UPDATE. If pkChng is false, then the key of
** the iDataCur content table is guaranteed to be unchanged by the UPDATE.
**
** For an INSERT, the pkChng boolean indicates whether or not the rowid
** was explicitly specified as part of the INSERT statement. If pkChng
** is zero, it means that the either rowid is computed automatically or
** that the table is a WITHOUT ROWID table and has no rowid. On an INSERT,
** pkChng will only be true if the INSERT statement provides an integer
** value for either the rowid column or its INTEGER PRIMARY KEY alias.
**
** The code generated by this routine will store new index entries into
** registers identified by aRegIdx[]. No index entry is created for
** indices where aRegIdx[i]==0. The order of indices in aRegIdx[] is
** the same as the order of indices on the linked list of indices
** at pTab->pIndex.
**
** (2019-05-07) The generated code also creates a new record for the
** main table, if pTab is a rowid table, and stores that record in the
** register identified by aRegIdx[nIdx] - in other words in the first
** entry of aRegIdx[] past the last index. It is important that the
** record be generated during constraint checks to avoid affinity changes
** to the register content that occur after constraint checks but before
** the new record is inserted.
**
** The caller must have already opened writeable cursors on the main
** table and all applicable indices (that is to say, all indices for which
** aRegIdx[] is not zero). iDataCur is the cursor for the main table when
** inserting or updating a rowid table, or the cursor for the PRIMARY KEY
** index when operating on a WITHOUT ROWID table. iIdxCur is the cursor
** for the first index in the pTab->pIndex list. Cursors for other indices
** are at iIdxCur+N for the N-th element of the pTab->pIndex list.
**
** This routine also generates code to check constraints. NOT NULL,
** CHECK, and UNIQUE constraints are all checked. If a constraint fails,
** then the appropriate action is performed. There are five possible
** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
**
** Constraint type Action What Happens
** --------------- ---------- ----------------------------------------
** any ROLLBACK The current transaction is rolled back and
** sqlite3_step() returns immediately with a
** return code of SQLITE_CONSTRAINT.
**
** any ABORT Back out changes from the current command
** only (do not do a complete rollback) then
** cause sqlite3_step() to return immediately
** with SQLITE_CONSTRAINT.
**
** any FAIL Sqlite3_step() returns immediately with a
** return code of SQLITE_CONSTRAINT. The
** transaction is not rolled back and any
** changes to prior rows are retained.
**
** any IGNORE The attempt in insert or update the current
** row is skipped, without throwing an error.
** Processing continues with the next row.
** (There is an immediate jump to ignoreDest.)
**
** NOT NULL REPLACE The NULL value is replace by the default
** value for that column. If the default value
** is NULL, the action is the same as ABORT.
**
** UNIQUE REPLACE The other row that conflicts with the row
** being inserted is removed.
**
** CHECK REPLACE Illegal. The results in an exception.
**
** Which action to take is determined by the overrideError parameter.
** Or if overrideError==OE_Default, then the pParse->onError parameter
** is used. Or if pParse->onError==OE_Default then the onError value
** for the constraint is used.
*/
SQLITE_PRIVATE void sqlite3GenerateConstraintChecks(
Parse *pParse, /* The parser context */
Table *pTab, /* The table being inserted or updated */
int *aRegIdx, /* Use register aRegIdx[i] for index i. 0 for unused */
int iDataCur, /* Canonical data cursor (main table or PK index) */
int iIdxCur, /* First index cursor */
int regNewData, /* First register in a range holding values to insert */
int regOldData, /* Previous content. 0 for INSERTs */
u8 pkChng, /* Non-zero if the rowid or PRIMARY KEY changed */
u8 overrideError, /* Override onError to this if not OE_Default */
int ignoreDest, /* Jump to this label on an OE_Ignore resolution */
int *pbMayReplace, /* OUT: Set to true if constraint may cause a replace */
int *aiChng, /* column i is unchanged if aiChng[i]<0 */
Upsert *pUpsert /* ON CONFLICT clauses, if any. NULL otherwise */
){
Vdbe *v; /* VDBE under constrution */
Index *pIdx; /* Pointer to one of the indices */
Index *pPk = 0; /* The PRIMARY KEY index */
sqlite3 *db; /* Database connection */
int i; /* loop counter */
int ix; /* Index loop counter */
int nCol; /* Number of columns */
int onError; /* Conflict resolution strategy */
int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
int nPkField; /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
Index *pUpIdx = 0; /* Index to which to apply the upsert */
u8 isUpdate; /* True if this is an UPDATE operation */
u8 bAffinityDone = 0; /* True if the OP_Affinity operation has been run */
int upsertBypass = 0; /* Address of Goto to bypass upsert subroutine */
int upsertJump = 0; /* Address of Goto that jumps into upsert subroutine */
int ipkTop = 0; /* Top of the IPK uniqueness check */
int ipkBottom = 0; /* OP_Goto at the end of the IPK uniqueness check */
/* Variables associated with retesting uniqueness constraints after
** replace triggers fire have run */
int regTrigCnt; /* Register used to count replace trigger invocations */
int addrRecheck = 0; /* Jump here to recheck all uniqueness constraints */
int lblRecheckOk = 0; /* Each recheck jumps to this label if it passes */
Trigger *pTrigger; /* List of DELETE triggers on the table pTab */
int nReplaceTrig = 0; /* Number of replace triggers coded */
isUpdate = regOldData!=0;
db = pParse->db;
v = pParse->pVdbe;
assert( v!=0 );
assert( pTab->pSelect==0 ); /* This table is not a VIEW */
nCol = pTab->nCol;
/* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for
** normal rowid tables. nPkField is the number of key fields in the
** pPk index or 1 for a rowid table. In other words, nPkField is the
** number of fields in the true primary key of the table. */
if( HasRowid(pTab) ){
pPk = 0;
nPkField = 1;
}else{
pPk = sqlite3PrimaryKeyIndex(pTab);
nPkField = pPk->nKeyCol;
}
/* Record that this module has started */
VdbeModuleComment((v, "BEGIN: GenCnstCks(%d,%d,%d,%d,%d)",
iDataCur, iIdxCur, regNewData, regOldData, pkChng));
/* Test all NOT NULL constraints.
*/
if( pTab->tabFlags & TF_HasNotNull ){
int b2ndPass = 0; /* True if currently running 2nd pass */
int nSeenReplace = 0; /* Number of ON CONFLICT REPLACE operations */
int nGenerated = 0; /* Number of generated columns with NOT NULL */
while(1){ /* Make 2 passes over columns. Exit loop via "break" */
for(i=0; i<nCol; i++){
int iReg; /* Register holding column value */
Column *pCol = &pTab->aCol[i]; /* The column to check for NOT NULL */
int isGenerated; /* non-zero if column is generated */
onError = pCol->notNull;
if( onError==OE_None ) continue; /* No NOT NULL on this column */
if( i==pTab->iPKey ){
continue; /* ROWID is never NULL */
}
isGenerated = pCol->colFlags & COLFLAG_GENERATED;
if( isGenerated && !b2ndPass ){
nGenerated++;
continue; /* Generated columns processed on 2nd pass */
}
if( aiChng && aiChng[i]<0 && !isGenerated ){
/* Do not check NOT NULL on columns that do not change */
continue;
}
if( overrideError!=OE_Default ){
onError = overrideError;
}else if( onError==OE_Default ){
onError = OE_Abort;
}
if( onError==OE_Replace ){
if( b2ndPass /* REPLACE becomes ABORT on the 2nd pass */
|| pCol->pDflt==0 /* REPLACE is ABORT if no DEFAULT value */
){
testcase( pCol->colFlags & COLFLAG_VIRTUAL );
testcase( pCol->colFlags & COLFLAG_STORED );
testcase( pCol->colFlags & COLFLAG_GENERATED );
onError = OE_Abort;
}else{
assert( !isGenerated );
}
}else if( b2ndPass && !isGenerated ){
continue;
}
assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
|| onError==OE_Ignore || onError==OE_Replace );
testcase( i!=sqlite3TableColumnToStorage(pTab, i) );
iReg = sqlite3TableColumnToStorage(pTab, i) + regNewData + 1;
switch( onError ){
case OE_Replace: {
int addr1 = sqlite3VdbeAddOp1(v, OP_NotNull, iReg);
VdbeCoverage(v);
assert( (pCol->colFlags & COLFLAG_GENERATED)==0 );
nSeenReplace++;
sqlite3ExprCodeCopy(pParse, pCol->pDflt, iReg);
sqlite3VdbeJumpHere(v, addr1);
break;
}
case OE_Abort:
sqlite3MayAbort(pParse);
/* no break */ deliberate_fall_through
case OE_Rollback:
case OE_Fail: {
char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,
pCol->zName);
sqlite3VdbeAddOp3(v, OP_HaltIfNull, SQLITE_CONSTRAINT_NOTNULL,
onError, iReg);
sqlite3VdbeAppendP4(v, zMsg, P4_DYNAMIC);
sqlite3VdbeChangeP5(v, P5_ConstraintNotNull);
VdbeCoverage(v);
break;
}
default: {
assert( onError==OE_Ignore );
sqlite3VdbeAddOp2(v, OP_IsNull, iReg, ignoreDest);
VdbeCoverage(v);
break;
}
} /* end switch(onError) */
} /* end loop i over columns */
if( nGenerated==0 && nSeenReplace==0 ){
/* If there are no generated columns with NOT NULL constraints
** and no NOT NULL ON CONFLICT REPLACE constraints, then a single
** pass is sufficient */
break;
}
if( b2ndPass ) break; /* Never need more than 2 passes */
b2ndPass = 1;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( nSeenReplace>0 && (pTab->tabFlags & TF_HasGenerated)!=0 ){
/* If any NOT NULL ON CONFLICT REPLACE constraints fired on the
** first pass, recomputed values for all generated columns, as
** those values might depend on columns affected by the REPLACE.
*/
sqlite3ComputeGeneratedColumns(pParse, regNewData+1, pTab);
}
#endif
} /* end of 2-pass loop */
} /* end if( has-not-null-constraints ) */
/* Test all CHECK constraints
*/
#ifndef SQLITE_OMIT_CHECK
if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
ExprList *pCheck = pTab->pCheck;
pParse->iSelfTab = -(regNewData+1);
onError = overrideError!=OE_Default ? overrideError : OE_Abort;
for(i=0; i<pCheck->nExpr; i++){
int allOk;
Expr *pCopy;
Expr *pExpr = pCheck->a[i].pExpr;
if( aiChng
&& !sqlite3ExprReferencesUpdatedColumn(pExpr, aiChng, pkChng)
){
/* The check constraints do not reference any of the columns being
** updated so there is no point it verifying the check constraint */
continue;
}
if( bAffinityDone==0 ){
sqlite3TableAffinity(v, pTab, regNewData+1);
bAffinityDone = 1;
}
allOk = sqlite3VdbeMakeLabel(pParse);
sqlite3VdbeVerifyAbortable(v, onError);
pCopy = sqlite3ExprDup(db, pExpr, 0);
if( !db->mallocFailed ){
sqlite3ExprIfTrue(pParse, pCopy, allOk, SQLITE_JUMPIFNULL);
}
sqlite3ExprDelete(db, pCopy);
if( onError==OE_Ignore ){
sqlite3VdbeGoto(v, ignoreDest);
}else{
char *zName = pCheck->a[i].zEName;
assert( zName!=0 || pParse->db->mallocFailed );
if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-26383-51744 */
sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
onError, zName, P4_TRANSIENT,
P5_ConstraintCheck);
}
sqlite3VdbeResolveLabel(v, allOk);
}
pParse->iSelfTab = 0;
}
#endif /* !defined(SQLITE_OMIT_CHECK) */
/* UNIQUE and PRIMARY KEY constraints should be handled in the following
** order:
**
** (1) OE_Update
** (2) OE_Abort, OE_Fail, OE_Rollback, OE_Ignore
** (3) OE_Replace
**
** OE_Fail and OE_Ignore must happen before any changes are made.
** OE_Update guarantees that only a single row will change, so it
** must happen before OE_Replace. Technically, OE_Abort and OE_Rollback
** could happen in any order, but they are grouped up front for
** convenience.
**
** 2018-08-14: Ticket https://www.sqlite.org/src/info/908f001483982c43
** The order of constraints used to have OE_Update as (2) and OE_Abort
** and so forth as (1). But apparently PostgreSQL checks the OE_Update
** constraint before any others, so it had to be moved.
**
** Constraint checking code is generated in this order:
** (A) The rowid constraint
** (B) Unique index constraints that do not have OE_Replace as their
** default conflict resolution strategy
** (C) Unique index that do use OE_Replace by default.
**
** The ordering of (2) and (3) is accomplished by making sure the linked
** list of indexes attached to a table puts all OE_Replace indexes last
** in the list. See sqlite3CreateIndex() for where that happens.
*/
if( pUpsert ){
if( pUpsert->pUpsertTarget==0 ){
/* An ON CONFLICT DO NOTHING clause, without a constraint-target.
** Make all unique constraint resolution be OE_Ignore */
assert( pUpsert->pUpsertSet==0 );
overrideError = OE_Ignore;
pUpsert = 0;
}else if( (pUpIdx = pUpsert->pUpsertIdx)!=0 ){
/* If the constraint-target uniqueness check must be run first.
** Jump to that uniqueness check now */
upsertJump = sqlite3VdbeAddOp0(v, OP_Goto);
VdbeComment((v, "UPSERT constraint goes first"));
}
}
/* Determine if it is possible that triggers (either explicitly coded
** triggers or FK resolution actions) might run as a result of deletes
** that happen when OE_Replace conflict resolution occurs. (Call these
** "replace triggers".) If any replace triggers run, we will need to
** recheck all of the uniqueness constraints after they have all run.
** But on the recheck, the resolution is OE_Abort instead of OE_Replace.
**
** If replace triggers are a possibility, then
**
** (1) Allocate register regTrigCnt and initialize it to zero.
** That register will count the number of replace triggers that
** fire. Constraint recheck only occurs if the number is positive.
** (2) Initialize pTrigger to the list of all DELETE triggers on pTab.
** (3) Initialize addrRecheck and lblRecheckOk
**
** The uniqueness rechecking code will create a series of tests to run
** in a second pass. The addrRecheck and lblRecheckOk variables are
** used to link together these tests which are separated from each other
** in the generate bytecode.
*/
if( (db->flags & (SQLITE_RecTriggers|SQLITE_ForeignKeys))==0 ){
/* There are not DELETE triggers nor FK constraints. No constraint
** rechecks are needed. */
pTrigger = 0;
regTrigCnt = 0;
}else{
if( db->flags&SQLITE_RecTriggers ){
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
regTrigCnt = pTrigger!=0 || sqlite3FkRequired(pParse, pTab, 0, 0);
}else{
pTrigger = 0;
regTrigCnt = sqlite3FkRequired(pParse, pTab, 0, 0);
}
if( regTrigCnt ){
/* Replace triggers might exist. Allocate the counter and
** initialize it to zero. */
regTrigCnt = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regTrigCnt);
VdbeComment((v, "trigger count"));
lblRecheckOk = sqlite3VdbeMakeLabel(pParse);
addrRecheck = lblRecheckOk;
}
}
/* If rowid is changing, make sure the new rowid does not previously
** exist in the table.
*/
if( pkChng && pPk==0 ){
int addrRowidOk = sqlite3VdbeMakeLabel(pParse);
/* Figure out what action to take in case of a rowid collision */
onError = pTab->keyConf;
if( overrideError!=OE_Default ){
onError = overrideError;
}else if( onError==OE_Default ){
onError = OE_Abort;
}
/* figure out whether or not upsert applies in this case */
if( pUpsert && pUpsert->pUpsertIdx==0 ){
if( pUpsert->pUpsertSet==0 ){
onError = OE_Ignore; /* DO NOTHING is the same as INSERT OR IGNORE */
}else{
onError = OE_Update; /* DO UPDATE */
}
}
/* If the response to a rowid conflict is REPLACE but the response
** to some other UNIQUE constraint is FAIL or IGNORE, then we need
** to defer the running of the rowid conflict checking until after
** the UNIQUE constraints have run.
*/
if( onError==OE_Replace /* IPK rule is REPLACE */
&& onError!=overrideError /* Rules for other contraints are different */
&& pTab->pIndex /* There exist other constraints */
){
ipkTop = sqlite3VdbeAddOp0(v, OP_Goto)+1;
VdbeComment((v, "defer IPK REPLACE until last"));
}
if( isUpdate ){
/* pkChng!=0 does not mean that the rowid has changed, only that
** it might have changed. Skip the conflict logic below if the rowid
** is unchanged. */
sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);
sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
VdbeCoverage(v);
}
/* Check to see if the new rowid already exists in the table. Skip
** the following conflict logic if it does not. */
VdbeNoopComment((v, "uniqueness check for ROWID"));
sqlite3VdbeVerifyAbortable(v, onError);
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);
VdbeCoverage(v);
switch( onError ){
default: {
onError = OE_Abort;
/* no break */ deliberate_fall_through
}
case OE_Rollback:
case OE_Abort:
case OE_Fail: {
testcase( onError==OE_Rollback );
testcase( onError==OE_Abort );
testcase( onError==OE_Fail );
sqlite3RowidConstraint(pParse, onError, pTab);
break;
}
case OE_Replace: {
/* If there are DELETE triggers on this table and the
** recursive-triggers flag is set, call GenerateRowDelete() to
** remove the conflicting row from the table. This will fire
** the triggers and remove both the table and index b-tree entries.
**
** Otherwise, if there are no triggers or the recursive-triggers
** flag is not set, but the table has one or more indexes, call
** GenerateRowIndexDelete(). This removes the index b-tree entries
** only. The table b-tree entry will be replaced by the new entry
** when it is inserted.
**
** If either GenerateRowDelete() or GenerateRowIndexDelete() is called,
** also invoke MultiWrite() to indicate that this VDBE may require
** statement rollback (if the statement is aborted after the delete
** takes place). Earlier versions called sqlite3MultiWrite() regardless,
** but being more selective here allows statements like:
**
** REPLACE INTO t(rowid) VALUES($newrowid)
**
** to run without a statement journal if there are no indexes on the
** table.
*/
if( regTrigCnt ){
sqlite3MultiWrite(pParse);
sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
regNewData, 1, 0, OE_Replace, 1, -1);
sqlite3VdbeAddOp2(v, OP_AddImm, regTrigCnt, 1); /* incr trigger cnt */
nReplaceTrig++;
}else{
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
assert( HasRowid(pTab) );
/* This OP_Delete opcode fires the pre-update-hook only. It does
** not modify the b-tree. It is more efficient to let the coming
** OP_Insert replace the existing entry than it is to delete the
** existing entry and then insert a new one. */
sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, OPFLAG_ISNOOP);
sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
if( pTab->pIndex ){
sqlite3MultiWrite(pParse);
sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,-1);
}
}
seenReplace = 1;
break;
}
#ifndef SQLITE_OMIT_UPSERT
case OE_Update: {
sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, 0, iDataCur);
/* no break */ deliberate_fall_through
}
#endif
case OE_Ignore: {
testcase( onError==OE_Ignore );
sqlite3VdbeGoto(v, ignoreDest);
break;
}
}
sqlite3VdbeResolveLabel(v, addrRowidOk);
if( ipkTop ){
ipkBottom = sqlite3VdbeAddOp0(v, OP_Goto);
sqlite3VdbeJumpHere(v, ipkTop-1);
}
}
/* Test all UNIQUE constraints by creating entries for each UNIQUE
** index and making sure that duplicate entries do not already exist.
** Compute the revised record entries for indices as we go.
**
** This loop also handles the case of the PRIMARY KEY index for a
** WITHOUT ROWID table.
*/
for(ix=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, ix++){
int regIdx; /* Range of registers hold conent for pIdx */
int regR; /* Range of registers holding conflicting PK */
int iThisCur; /* Cursor for this UNIQUE index */
int addrUniqueOk; /* Jump here if the UNIQUE constraint is satisfied */
int addrConflictCk; /* First opcode in the conflict check logic */
if( aRegIdx[ix]==0 ) continue; /* Skip indices that do not change */
if( pUpIdx==pIdx ){
addrUniqueOk = upsertJump+1;
upsertBypass = sqlite3VdbeGoto(v, 0);
VdbeComment((v, "Skip upsert subroutine"));
sqlite3VdbeJumpHere(v, upsertJump);
}else{
addrUniqueOk = sqlite3VdbeMakeLabel(pParse);
}
if( bAffinityDone==0 && (pUpIdx==0 || pUpIdx==pIdx) ){
sqlite3TableAffinity(v, pTab, regNewData+1);
bAffinityDone = 1;
}
VdbeNoopComment((v, "prep index %s", pIdx->zName));
iThisCur = iIdxCur+ix;
/* Skip partial indices for which the WHERE clause is not true */
if( pIdx->pPartIdxWhere ){
sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
pParse->iSelfTab = -(regNewData+1);
sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
SQLITE_JUMPIFNULL);
pParse->iSelfTab = 0;
}
/* Create a record for this index entry as it should appear after
** the insert or update. Store that record in the aRegIdx[ix] register
*/
regIdx = aRegIdx[ix]+1;
for(i=0; i<pIdx->nColumn; i++){
int iField = pIdx->aiColumn[i];
int x;
if( iField==XN_EXPR ){
pParse->iSelfTab = -(regNewData+1);
sqlite3ExprCodeCopy(pParse, pIdx->aColExpr->a[i].pExpr, regIdx+i);
pParse->iSelfTab = 0;
VdbeComment((v, "%s column %d", pIdx->zName, i));
}else if( iField==XN_ROWID || iField==pTab->iPKey ){
x = regNewData;
sqlite3VdbeAddOp2(v, OP_IntCopy, x, regIdx+i);
VdbeComment((v, "rowid"));
}else{
testcase( sqlite3TableColumnToStorage(pTab, iField)!=iField );
x = sqlite3TableColumnToStorage(pTab, iField) + regNewData + 1;
sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
VdbeComment((v, "%s", pTab->aCol[iField].zName));
}
}
sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
VdbeComment((v, "for %s", pIdx->zName));
#ifdef SQLITE_ENABLE_NULL_TRIM
if( pIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){
sqlite3SetMakeRecordP5(v, pIdx->pTable);
}
#endif
sqlite3VdbeReleaseRegisters(pParse, regIdx, pIdx->nColumn, 0, 0);
/* In an UPDATE operation, if this index is the PRIMARY KEY index
** of a WITHOUT ROWID table and there has been no change the
** primary key, then no collision is possible. The collision detection
** logic below can all be skipped. */
if( isUpdate && pPk==pIdx && pkChng==0 ){
sqlite3VdbeResolveLabel(v, addrUniqueOk);
continue;
}
/* Find out what action to take in case there is a uniqueness conflict */
onError = pIdx->onError;
if( onError==OE_None ){
sqlite3VdbeResolveLabel(v, addrUniqueOk);
continue; /* pIdx is not a UNIQUE index */
}
if( overrideError!=OE_Default ){
onError = overrideError;
}else if( onError==OE_Default ){
onError = OE_Abort;
}
/* Figure out if the upsert clause applies to this index */
if( pUpIdx==pIdx ){
if( pUpsert->pUpsertSet==0 ){
onError = OE_Ignore; /* DO NOTHING is the same as INSERT OR IGNORE */
}else{
onError = OE_Update; /* DO UPDATE */
}
}
/* Collision detection may be omitted if all of the following are true:
** (1) The conflict resolution algorithm is REPLACE
** (2) The table is a WITHOUT ROWID table
** (3) There are no secondary indexes on the table
** (4) No delete triggers need to be fired if there is a conflict
** (5) No FK constraint counters need to be updated if a conflict occurs.
**
** This is not possible for ENABLE_PREUPDATE_HOOK builds, as the row
** must be explicitly deleted in order to ensure any pre-update hook
** is invoked. */
#ifndef SQLITE_ENABLE_PREUPDATE_HOOK
if( (ix==0 && pIdx->pNext==0) /* Condition 3 */
&& pPk==pIdx /* Condition 2 */
&& onError==OE_Replace /* Condition 1 */
&& ( 0==(db->flags&SQLITE_RecTriggers) || /* Condition 4 */
0==sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0))
&& ( 0==(db->flags&SQLITE_ForeignKeys) || /* Condition 5 */
(0==pTab->pFKey && 0==sqlite3FkReferences(pTab)))
){
sqlite3VdbeResolveLabel(v, addrUniqueOk);
continue;
}
#endif /* ifndef SQLITE_ENABLE_PREUPDATE_HOOK */
/* Check to see if the new index entry will be unique */
sqlite3VdbeVerifyAbortable(v, onError);
addrConflictCk =
sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
regIdx, pIdx->nKeyCol); VdbeCoverage(v);
/* Generate code to handle collisions */
regR = (pIdx==pPk) ? regIdx : sqlite3GetTempRange(pParse, nPkField);
if( isUpdate || onError==OE_Replace ){
if( HasRowid(pTab) ){
sqlite3VdbeAddOp2(v, OP_IdxRowid, iThisCur, regR);
/* Conflict only if the rowid of the existing index entry
** is different from old-rowid */
if( isUpdate ){
sqlite3VdbeAddOp3(v, OP_Eq, regR, addrUniqueOk, regOldData);
sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
VdbeCoverage(v);
}
}else{
int x;
/* Extract the PRIMARY KEY from the end of the index entry and
** store it in registers regR..regR+nPk-1 */
if( pIdx!=pPk ){
for(i=0; i<pPk->nKeyCol; i++){
assert( pPk->aiColumn[i]>=0 );
x = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[i]);
sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);
VdbeComment((v, "%s.%s", pTab->zName,
pTab->aCol[pPk->aiColumn[i]].zName));
}
}
if( isUpdate ){
/* If currently processing the PRIMARY KEY of a WITHOUT ROWID
** table, only conflict if the new PRIMARY KEY values are actually
** different from the old.
**
** For a UNIQUE index, only conflict if the PRIMARY KEY values
** of the matched index row are different from the original PRIMARY
** KEY values of this row before the update. */
int addrJump = sqlite3VdbeCurrentAddr(v)+pPk->nKeyCol;
int op = OP_Ne;
int regCmp = (IsPrimaryKeyIndex(pIdx) ? regIdx : regR);
for(i=0; i<pPk->nKeyCol; i++){
char *p4 = (char*)sqlite3LocateCollSeq(pParse, pPk->azColl[i]);
x = pPk->aiColumn[i];
assert( x>=0 );
if( i==(pPk->nKeyCol-1) ){
addrJump = addrUniqueOk;
op = OP_Eq;
}
x = sqlite3TableColumnToStorage(pTab, x);
sqlite3VdbeAddOp4(v, op,
regOldData+1+x, addrJump, regCmp+i, p4, P4_COLLSEQ
);
sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
VdbeCoverageIf(v, op==OP_Eq);
VdbeCoverageIf(v, op==OP_Ne);
}
}
}
}
/* Generate code that executes if the new index entry is not unique */
assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
|| onError==OE_Ignore || onError==OE_Replace || onError==OE_Update );
switch( onError ){
case OE_Rollback:
case OE_Abort:
case OE_Fail: {
testcase( onError==OE_Rollback );
testcase( onError==OE_Abort );
testcase( onError==OE_Fail );
sqlite3UniqueConstraint(pParse, onError, pIdx);
break;
}
#ifndef SQLITE_OMIT_UPSERT
case OE_Update: {
sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, pIdx, iIdxCur+ix);
/* no break */ deliberate_fall_through
}
#endif
case OE_Ignore: {
testcase( onError==OE_Ignore );
sqlite3VdbeGoto(v, ignoreDest);
break;
}
default: {
int nConflictCk; /* Number of opcodes in conflict check logic */
assert( onError==OE_Replace );
nConflictCk = sqlite3VdbeCurrentAddr(v) - addrConflictCk;
assert( nConflictCk>0 );
testcase( nConflictCk>1 );
if( regTrigCnt ){
sqlite3MultiWrite(pParse);
nReplaceTrig++;
}
if( pTrigger && isUpdate ){
sqlite3VdbeAddOp1(v, OP_CursorLock, iDataCur);
}
sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
regR, nPkField, 0, OE_Replace,
(pIdx==pPk ? ONEPASS_SINGLE : ONEPASS_OFF), iThisCur);
if( pTrigger && isUpdate ){
sqlite3VdbeAddOp1(v, OP_CursorUnlock, iDataCur);
}
if( regTrigCnt ){
int addrBypass; /* Jump destination to bypass recheck logic */
sqlite3VdbeAddOp2(v, OP_AddImm, regTrigCnt, 1); /* incr trigger cnt */
addrBypass = sqlite3VdbeAddOp0(v, OP_Goto); /* Bypass recheck */
VdbeComment((v, "bypass recheck"));
/* Here we insert code that will be invoked after all constraint
** checks have run, if and only if one or more replace triggers
** fired. */
sqlite3VdbeResolveLabel(v, lblRecheckOk);
lblRecheckOk = sqlite3VdbeMakeLabel(pParse);
if( pIdx->pPartIdxWhere ){
/* Bypass the recheck if this partial index is not defined
** for the current row */
sqlite3VdbeAddOp2(v, OP_IsNull, regIdx-1, lblRecheckOk);
VdbeCoverage(v);
}
/* Copy the constraint check code from above, except change
** the constraint-ok jump destination to be the address of
** the next retest block */
while( nConflictCk>0 ){
VdbeOp x; /* Conflict check opcode to copy */
/* The sqlite3VdbeAddOp4() call might reallocate the opcode array.
** Hence, make a complete copy of the opcode, rather than using
** a pointer to the opcode. */
x = *sqlite3VdbeGetOp(v, addrConflictCk);
if( x.opcode!=OP_IdxRowid ){
int p2; /* New P2 value for copied conflict check opcode */
const char *zP4;
if( sqlite3OpcodeProperty[x.opcode]&OPFLG_JUMP ){
p2 = lblRecheckOk;
}else{
p2 = x.p2;
}
zP4 = x.p4type==P4_INT32 ? SQLITE_INT_TO_PTR(x.p4.i) : x.p4.z;
sqlite3VdbeAddOp4(v, x.opcode, x.p1, p2, x.p3, zP4, x.p4type);
sqlite3VdbeChangeP5(v, x.p5);
VdbeCoverageIf(v, p2!=x.p2);
}
nConflictCk--;
addrConflictCk++;
}
/* If the retest fails, issue an abort */
sqlite3UniqueConstraint(pParse, OE_Abort, pIdx);
sqlite3VdbeJumpHere(v, addrBypass); /* Terminate the recheck bypass */
}
seenReplace = 1;
break;
}
}
if( pUpIdx==pIdx ){
sqlite3VdbeGoto(v, upsertJump+1);
sqlite3VdbeJumpHere(v, upsertBypass);
}else{
sqlite3VdbeResolveLabel(v, addrUniqueOk);
}
if( regR!=regIdx ) sqlite3ReleaseTempRange(pParse, regR, nPkField);
}
/* If the IPK constraint is a REPLACE, run it last */
if( ipkTop ){
sqlite3VdbeGoto(v, ipkTop);
VdbeComment((v, "Do IPK REPLACE"));
sqlite3VdbeJumpHere(v, ipkBottom);
}
/* Recheck all uniqueness constraints after replace triggers have run */
testcase( regTrigCnt!=0 && nReplaceTrig==0 );
assert( regTrigCnt!=0 || nReplaceTrig==0 );
if( nReplaceTrig ){
sqlite3VdbeAddOp2(v, OP_IfNot, regTrigCnt, lblRecheckOk);VdbeCoverage(v);
if( !pPk ){
if( isUpdate ){
sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRecheck, regOldData);
sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
VdbeCoverage(v);
}
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRecheck, regNewData);
VdbeCoverage(v);
sqlite3RowidConstraint(pParse, OE_Abort, pTab);
}else{
sqlite3VdbeGoto(v, addrRecheck);
}
sqlite3VdbeResolveLabel(v, lblRecheckOk);
}
/* Generate the table record */
if( HasRowid(pTab) ){
int regRec = aRegIdx[ix];
sqlite3VdbeAddOp3(v, OP_MakeRecord, regNewData+1, pTab->nNVCol, regRec);
sqlite3SetMakeRecordP5(v, pTab);
if( !bAffinityDone ){
sqlite3TableAffinity(v, pTab, 0);
}
}
*pbMayReplace = seenReplace;
VdbeModuleComment((v, "END: GenCnstCks(%d)", seenReplace));
}
#ifdef SQLITE_ENABLE_NULL_TRIM
/*
** Change the P5 operand on the last opcode (which should be an OP_MakeRecord)
** to be the number of columns in table pTab that must not be NULL-trimmed.
**
** Or if no columns of pTab may be NULL-trimmed, leave P5 at zero.
*/
SQLITE_PRIVATE void sqlite3SetMakeRecordP5(Vdbe *v, Table *pTab){
u16 i;
/* Records with omitted columns are only allowed for schema format
** version 2 and later (SQLite version 3.1.4, 2005-02-20). */
if( pTab->pSchema->file_format<2 ) return;
for(i=pTab->nCol-1; i>0; i--){
if( pTab->aCol[i].pDflt!=0 ) break;
if( pTab->aCol[i].colFlags & COLFLAG_PRIMKEY ) break;
}
sqlite3VdbeChangeP5(v, i+1);
}
#endif
/*
** This routine generates code to finish the INSERT or UPDATE operation
** that was started by a prior call to sqlite3GenerateConstraintChecks.
** A consecutive range of registers starting at regNewData contains the
** rowid and the content to be inserted.
**
** The arguments to this routine should be the same as the first six
** arguments to sqlite3GenerateConstraintChecks.
*/
SQLITE_PRIVATE void sqlite3CompleteInsertion(
Parse *pParse, /* The parser context */
Table *pTab, /* the table into which we are inserting */
int iDataCur, /* Cursor of the canonical data source */
int iIdxCur, /* First index cursor */
int regNewData, /* Range of content */
int *aRegIdx, /* Register used by each index. 0 for unused indices */
int update_flags, /* True for UPDATE, False for INSERT */
int appendBias, /* True if this is likely to be an append */
int useSeekResult /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
){
Vdbe *v; /* Prepared statements under construction */
Index *pIdx; /* An index being inserted or updated */
u8 pik_flags; /* flag values passed to the btree insert */
int i; /* Loop counter */
assert( update_flags==0
|| update_flags==OPFLAG_ISUPDATE
|| update_flags==(OPFLAG_ISUPDATE|OPFLAG_SAVEPOSITION)
);
v = pParse->pVdbe;
assert( v!=0 );
assert( pTab->pSelect==0 ); /* This table is not a VIEW */
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
/* All REPLACE indexes are at the end of the list */
assert( pIdx->onError!=OE_Replace
|| pIdx->pNext==0
|| pIdx->pNext->onError==OE_Replace );
if( aRegIdx[i]==0 ) continue;
if( pIdx->pPartIdxWhere ){
sqlite3VdbeAddOp2(v, OP_IsNull, aRegIdx[i], sqlite3VdbeCurrentAddr(v)+2);
VdbeCoverage(v);
}
pik_flags = (useSeekResult ? OPFLAG_USESEEKRESULT : 0);
if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
assert( pParse->nested==0 );
pik_flags |= OPFLAG_NCHANGE;
pik_flags |= (update_flags & OPFLAG_SAVEPOSITION);
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
if( update_flags==0 ){
int r = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_Integer, 0, r);
sqlite3VdbeAddOp4(v, OP_Insert,
iIdxCur+i, aRegIdx[i], r, (char*)pTab, P4_TABLE
);
sqlite3VdbeChangeP5(v, OPFLAG_ISNOOP);
sqlite3ReleaseTempReg(pParse, r);
}
#endif
}
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iIdxCur+i, aRegIdx[i],
aRegIdx[i]+1,
pIdx->uniqNotNull ? pIdx->nKeyCol: pIdx->nColumn);
sqlite3VdbeChangeP5(v, pik_flags);
}
if( !HasRowid(pTab) ) return;
if( pParse->nested ){
pik_flags = 0;
}else{
pik_flags = OPFLAG_NCHANGE;
pik_flags |= (update_flags?update_flags:OPFLAG_LASTROWID);
}
if( appendBias ){
pik_flags |= OPFLAG_APPEND;
}
if( useSeekResult ){
pik_flags |= OPFLAG_USESEEKRESULT;
}
sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, aRegIdx[i], regNewData);
if( !pParse->nested ){
sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
}
sqlite3VdbeChangeP5(v, pik_flags);
}
/*
** Allocate cursors for the pTab table and all its indices and generate
** code to open and initialized those cursors.
**
** The cursor for the object that contains the complete data (normally
** the table itself, but the PRIMARY KEY index in the case of a WITHOUT
** ROWID table) is returned in *piDataCur. The first index cursor is
** returned in *piIdxCur. The number of indices is returned.
**
** Use iBase as the first cursor (either the *piDataCur for rowid tables
** or the first index for WITHOUT ROWID tables) if it is non-negative.
** If iBase is negative, then allocate the next available cursor.
**
** For a rowid table, *piDataCur will be exactly one less than *piIdxCur.
** For a WITHOUT ROWID table, *piDataCur will be somewhere in the range
** of *piIdxCurs, depending on where the PRIMARY KEY index appears on the
** pTab->pIndex list.
**
** If pTab is a virtual table, then this routine is a no-op and the
** *piDataCur and *piIdxCur values are left uninitialized.
*/
SQLITE_PRIVATE int sqlite3OpenTableAndIndices(
Parse *pParse, /* Parsing context */
Table *pTab, /* Table to be opened */
int op, /* OP_OpenRead or OP_OpenWrite */
u8 p5, /* P5 value for OP_Open* opcodes (except on WITHOUT ROWID) */
int iBase, /* Use this for the table cursor, if there is one */
u8 *aToOpen, /* If not NULL: boolean for each table and index */
int *piDataCur, /* Write the database source cursor number here */
int *piIdxCur /* Write the first index cursor number here */
){
int i;
int iDb;
int iDataCur;
Index *pIdx;
Vdbe *v;
assert( op==OP_OpenRead || op==OP_OpenWrite );
assert( op==OP_OpenWrite || p5==0 );
if( IsVirtual(pTab) ){
/* This routine is a no-op for virtual tables. Leave the output
** variables *piDataCur and *piIdxCur uninitialized so that valgrind
** can detect if they are used by mistake in the caller. */
return 0;
}
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
v = pParse->pVdbe;
assert( v!=0 );
if( iBase<0 ) iBase = pParse->nTab;
iDataCur = iBase++;
if( piDataCur ) *piDataCur = iDataCur;
if( HasRowid(pTab) && (aToOpen==0 || aToOpen[0]) ){
sqlite3OpenTable(pParse, iDataCur, iDb, pTab, op);
}else{
sqlite3TableLock(pParse, iDb, pTab->tnum, op==OP_OpenWrite, pTab->zName);
}
if( piIdxCur ) *piIdxCur = iBase;
for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
int iIdxCur = iBase++;
assert( pIdx->pSchema==pTab->pSchema );
if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
if( piDataCur ) *piDataCur = iIdxCur;
p5 = 0;
}
if( aToOpen==0 || aToOpen[i+1] ){
sqlite3VdbeAddOp3(v, op, iIdxCur, pIdx->tnum, iDb);
sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
sqlite3VdbeChangeP5(v, p5);
VdbeComment((v, "%s", pIdx->zName));
}
}
if( iBase>pParse->nTab ) pParse->nTab = iBase;
return i;
}
#ifdef SQLITE_TEST
/*
** The following global variable is incremented whenever the
** transfer optimization is used. This is used for testing
** purposes only - to make sure the transfer optimization really
** is happening when it is supposed to.
*/
SQLITE_API int sqlite3_xferopt_count;
#endif /* SQLITE_TEST */
#ifndef SQLITE_OMIT_XFER_OPT
/*
** Check to see if index pSrc is compatible as a source of data
** for index pDest in an insert transfer optimization. The rules
** for a compatible index:
**
** * The index is over the same set of columns
** * The same DESC and ASC markings occurs on all columns
** * The same onError processing (OE_Abort, OE_Ignore, etc)
** * The same collating sequence on each column
** * The index has the exact same WHERE clause
*/
static int xferCompatibleIndex(Index *pDest, Index *pSrc){
int i;
assert( pDest && pSrc );
assert( pDest->pTable!=pSrc->pTable );
if( pDest->nKeyCol!=pSrc->nKeyCol || pDest->nColumn!=pSrc->nColumn ){
return 0; /* Different number of columns */
}
if( pDest->onError!=pSrc->onError ){
return 0; /* Different conflict resolution strategies */
}
for(i=0; i<pSrc->nKeyCol; i++){
if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
return 0; /* Different columns indexed */
}
if( pSrc->aiColumn[i]==XN_EXPR ){
assert( pSrc->aColExpr!=0 && pDest->aColExpr!=0 );
if( sqlite3ExprCompare(0, pSrc->aColExpr->a[i].pExpr,
pDest->aColExpr->a[i].pExpr, -1)!=0 ){
return 0; /* Different expressions in the index */
}
}
if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
return 0; /* Different sort orders */
}
if( sqlite3_stricmp(pSrc->azColl[i],pDest->azColl[i])!=0 ){
return 0; /* Different collating sequences */
}
}
if( sqlite3ExprCompare(0, pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){
return 0; /* Different WHERE clauses */
}
/* If no test above fails then the indices must be compatible */
return 1;
}
/*
** Attempt the transfer optimization on INSERTs of the form
**
** INSERT INTO tab1 SELECT * FROM tab2;
**
** The xfer optimization transfers raw records from tab2 over to tab1.
** Columns are not decoded and reassembled, which greatly improves
** performance. Raw index records are transferred in the same way.
**
** The xfer optimization is only attempted if tab1 and tab2 are compatible.
** There are lots of rules for determining compatibility - see comments
** embedded in the code for details.
**
** This routine returns TRUE if the optimization is guaranteed to be used.
** Sometimes the xfer optimization will only work if the destination table
** is empty - a factor that can only be determined at run-time. In that
** case, this routine generates code for the xfer optimization but also
** does a test to see if the destination table is empty and jumps over the
** xfer optimization code if the test fails. In that case, this routine
** returns FALSE so that the caller will know to go ahead and generate
** an unoptimized transfer. This routine also returns FALSE if there
** is no chance that the xfer optimization can be applied.
**
** This optimization is particularly useful at making VACUUM run faster.
*/
static int xferOptimization(
Parse *pParse, /* Parser context */
Table *pDest, /* The table we are inserting into */
Select *pSelect, /* A SELECT statement to use as the data source */
int onError, /* How to handle constraint errors */
int iDbDest /* The database of pDest */
){
sqlite3 *db = pParse->db;
ExprList *pEList; /* The result set of the SELECT */
Table *pSrc; /* The table in the FROM clause of SELECT */
Index *pSrcIdx, *pDestIdx; /* Source and destination indices */
struct SrcList_item *pItem; /* An element of pSelect->pSrc */
int i; /* Loop counter */
int iDbSrc; /* The database of pSrc */
int iSrc, iDest; /* Cursors from source and destination */
int addr1, addr2; /* Loop addresses */
int emptyDestTest = 0; /* Address of test for empty pDest */
int emptySrcTest = 0; /* Address of test for empty pSrc */
Vdbe *v; /* The VDBE we are building */
int regAutoinc; /* Memory register used by AUTOINC */
int destHasUniqueIdx = 0; /* True if pDest has a UNIQUE index */
int regData, regRowid; /* Registers holding data and rowid */
if( pSelect==0 ){
return 0; /* Must be of the form INSERT INTO ... SELECT ... */
}
if( pParse->pWith || pSelect->pWith ){
/* Do not attempt to process this query if there are an WITH clauses
** attached to it. Proceeding may generate a false "no such table: xxx"
** error if pSelect reads from a CTE named "xxx". */
return 0;
}
if( sqlite3TriggerList(pParse, pDest) ){
return 0; /* tab1 must not have triggers */
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pDest) ){
return 0; /* tab1 must not be a virtual table */
}
#endif
if( onError==OE_Default ){
if( pDest->iPKey>=0 ) onError = pDest->keyConf;
if( onError==OE_Default ) onError = OE_Abort;
}
assert(pSelect->pSrc); /* allocated even if there is no FROM clause */
if( pSelect->pSrc->nSrc!=1 ){
return 0; /* FROM clause must have exactly one term */
}
if( pSelect->pSrc->a[0].pSelect ){
return 0; /* FROM clause cannot contain a subquery */
}
if( pSelect->pWhere ){
return 0; /* SELECT may not have a WHERE clause */
}
if( pSelect->pOrderBy ){
return 0; /* SELECT may not have an ORDER BY clause */
}
/* Do not need to test for a HAVING clause. If HAVING is present but
** there is no ORDER BY, we will get an error. */
if( pSelect->pGroupBy ){
return 0; /* SELECT may not have a GROUP BY clause */
}
if( pSelect->pLimit ){
return 0; /* SELECT may not have a LIMIT clause */
}
if( pSelect->pPrior ){
return 0; /* SELECT may not be a compound query */
}
if( pSelect->selFlags & SF_Distinct ){
return 0; /* SELECT may not be DISTINCT */
}
pEList = pSelect->pEList;
assert( pEList!=0 );
if( pEList->nExpr!=1 ){
return 0; /* The result set must have exactly one column */
}
assert( pEList->a[0].pExpr );
if( pEList->a[0].pExpr->op!=TK_ASTERISK ){
return 0; /* The result set must be the special operator "*" */
}
/* At this point we have established that the statement is of the
** correct syntactic form to participate in this optimization. Now
** we have to check the semantics.
*/
pItem = pSelect->pSrc->a;
pSrc = sqlite3LocateTableItem(pParse, 0, pItem);
if( pSrc==0 ){
return 0; /* FROM clause does not contain a real table */
}
if( pSrc->tnum==pDest->tnum && pSrc->pSchema==pDest->pSchema ){
testcase( pSrc!=pDest ); /* Possible due to bad sqlite_schema.rootpage */
return 0; /* tab1 and tab2 may not be the same table */
}
if( HasRowid(pDest)!=HasRowid(pSrc) ){
return 0; /* source and destination must both be WITHOUT ROWID or not */
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pSrc) ){
return 0; /* tab2 must not be a virtual table */
}
#endif
if( pSrc->pSelect ){
return 0; /* tab2 may not be a view */
}
if( pDest->nCol!=pSrc->nCol ){
return 0; /* Number of columns must be the same in tab1 and tab2 */
}
if( pDest->iPKey!=pSrc->iPKey ){
return 0; /* Both tables must have the same INTEGER PRIMARY KEY */
}
for(i=0; i<pDest->nCol; i++){
Column *pDestCol = &pDest->aCol[i];
Column *pSrcCol = &pSrc->aCol[i];
#ifdef SQLITE_ENABLE_HIDDEN_COLUMNS
if( (db->mDbFlags & DBFLAG_Vacuum)==0
&& (pDestCol->colFlags | pSrcCol->colFlags) & COLFLAG_HIDDEN
){
return 0; /* Neither table may have __hidden__ columns */
}
#endif
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* Even if tables t1 and t2 have identical schemas, if they contain
** generated columns, then this statement is semantically incorrect:
**
** INSERT INTO t2 SELECT * FROM t1;
**
** The reason is that generated column values are returned by the
** the SELECT statement on the right but the INSERT statement on the
** left wants them to be omitted.
**
** Nevertheless, this is a useful notational shorthand to tell SQLite
** to do a bulk transfer all of the content from t1 over to t2.
**
** We could, in theory, disable this (except for internal use by the
** VACUUM command where it is actually needed). But why do that? It
** seems harmless enough, and provides a useful service.
*/
if( (pDestCol->colFlags & COLFLAG_GENERATED) !=
(pSrcCol->colFlags & COLFLAG_GENERATED) ){
return 0; /* Both columns have the same generated-column type */
}
/* But the transfer is only allowed if both the source and destination
** tables have the exact same expressions for generated columns.
** This requirement could be relaxed for VIRTUAL columns, I suppose.
*/
if( (pDestCol->colFlags & COLFLAG_GENERATED)!=0 ){
if( sqlite3ExprCompare(0, pSrcCol->pDflt, pDestCol->pDflt, -1)!=0 ){
testcase( pDestCol->colFlags & COLFLAG_VIRTUAL );
testcase( pDestCol->colFlags & COLFLAG_STORED );
return 0; /* Different generator expressions */
}
}
#endif
if( pDestCol->affinity!=pSrcCol->affinity ){
return 0; /* Affinity must be the same on all columns */
}
if( sqlite3_stricmp(pDestCol->zColl, pSrcCol->zColl)!=0 ){
return 0; /* Collating sequence must be the same on all columns */
}
if( pDestCol->notNull && !pSrcCol->notNull ){
return 0; /* tab2 must be NOT NULL if tab1 is */
}
/* Default values for second and subsequent columns need to match. */
if( (pDestCol->colFlags & COLFLAG_GENERATED)==0 && i>0 ){
assert( pDestCol->pDflt==0 || pDestCol->pDflt->op==TK_SPAN );
assert( pSrcCol->pDflt==0 || pSrcCol->pDflt->op==TK_SPAN );
if( (pDestCol->pDflt==0)!=(pSrcCol->pDflt==0)
|| (pDestCol->pDflt && strcmp(pDestCol->pDflt->u.zToken,
pSrcCol->pDflt->u.zToken)!=0)
){
return 0; /* Default values must be the same for all columns */
}
}
}
for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
if( IsUniqueIndex(pDestIdx) ){
destHasUniqueIdx = 1;
}
for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
}
if( pSrcIdx==0 ){
return 0; /* pDestIdx has no corresponding index in pSrc */
}
if( pSrcIdx->tnum==pDestIdx->tnum && pSrc->pSchema==pDest->pSchema
&& sqlite3FaultSim(411)==SQLITE_OK ){
/* The sqlite3FaultSim() call allows this corruption test to be
** bypassed during testing, in order to exercise other corruption tests
** further downstream. */
return 0; /* Corrupt schema - two indexes on the same btree */
}
}
#ifndef SQLITE_OMIT_CHECK
if( pDest->pCheck && sqlite3ExprListCompare(pSrc->pCheck,pDest->pCheck,-1) ){
return 0; /* Tables have different CHECK constraints. Ticket #2252 */
}
#endif
#ifndef SQLITE_OMIT_FOREIGN_KEY
/* Disallow the transfer optimization if the destination table constains
** any foreign key constraints. This is more restrictive than necessary.
** But the main beneficiary of the transfer optimization is the VACUUM
** command, and the VACUUM command disables foreign key constraints. So
** the extra complication to make this rule less restrictive is probably
** not worth the effort. Ticket [6284df89debdfa61db8073e062908af0c9b6118e]
*/
if( (db->flags & SQLITE_ForeignKeys)!=0 && pDest->pFKey!=0 ){
return 0;
}
#endif
if( (db->flags & SQLITE_CountRows)!=0 ){
return 0; /* xfer opt does not play well with PRAGMA count_changes */
}
/* If we get this far, it means that the xfer optimization is at
** least a possibility, though it might only work if the destination
** table (tab1) is initially empty.
*/
#ifdef SQLITE_TEST
sqlite3_xferopt_count++;
#endif
iDbSrc = sqlite3SchemaToIndex(db, pSrc->pSchema);
v = sqlite3GetVdbe(pParse);
sqlite3CodeVerifySchema(pParse, iDbSrc);
iSrc = pParse->nTab++;
iDest = pParse->nTab++;
regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
regData = sqlite3GetTempReg(pParse);
regRowid = sqlite3GetTempReg(pParse);
sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
assert( HasRowid(pDest) || destHasUniqueIdx );
if( (db->mDbFlags & DBFLAG_Vacuum)==0 && (
(pDest->iPKey<0 && pDest->pIndex!=0) /* (1) */
|| destHasUniqueIdx /* (2) */
|| (onError!=OE_Abort && onError!=OE_Rollback) /* (3) */
)){
/* In some circumstances, we are able to run the xfer optimization
** only if the destination table is initially empty. Unless the
** DBFLAG_Vacuum flag is set, this block generates code to make
** that determination. If DBFLAG_Vacuum is set, then the destination
** table is always empty.
**
** Conditions under which the destination must be empty:
**
** (1) There is no INTEGER PRIMARY KEY but there are indices.
** (If the destination is not initially empty, the rowid fields
** of index entries might need to change.)
**
** (2) The destination has a unique index. (The xfer optimization
** is unable to test uniqueness.)
**
** (3) onError is something other than OE_Abort and OE_Rollback.
*/
addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0); VdbeCoverage(v);
emptyDestTest = sqlite3VdbeAddOp0(v, OP_Goto);
sqlite3VdbeJumpHere(v, addr1);
}
if( HasRowid(pSrc) ){
u8 insFlags;
sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
if( pDest->iPKey>=0 ){
addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
sqlite3VdbeVerifyAbortable(v, onError);
addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
VdbeCoverage(v);
sqlite3RowidConstraint(pParse, onError, pDest);
sqlite3VdbeJumpHere(v, addr2);
autoIncStep(pParse, regAutoinc, regRowid);
}else if( pDest->pIndex==0 && !(db->mDbFlags & DBFLAG_VacuumInto) ){
addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
}else{
addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
assert( (pDest->tabFlags & TF_Autoincrement)==0 );
}
if( db->mDbFlags & DBFLAG_Vacuum ){
sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
insFlags = OPFLAG_APPEND|OPFLAG_USESEEKRESULT;
}else{
insFlags = OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND;
}
sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
sqlite3VdbeAddOp4(v, OP_Insert, iDest, regData, regRowid,
(char*)pDest, P4_TABLE);
sqlite3VdbeChangeP5(v, insFlags);
sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
}else{
sqlite3TableLock(pParse, iDbDest, pDest->tnum, 1, pDest->zName);
sqlite3TableLock(pParse, iDbSrc, pSrc->tnum, 0, pSrc->zName);
}
for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
u8 idxInsFlags = 0;
for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
}
assert( pSrcIdx );
sqlite3VdbeAddOp3(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc);
sqlite3VdbeSetP4KeyInfo(pParse, pSrcIdx);
VdbeComment((v, "%s", pSrcIdx->zName));
sqlite3VdbeAddOp3(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest);
sqlite3VdbeSetP4KeyInfo(pParse, pDestIdx);
sqlite3VdbeChangeP5(v, OPFLAG_BULKCSR);
VdbeComment((v, "%s", pDestIdx->zName));
addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0); VdbeCoverage(v);
if( db->mDbFlags & DBFLAG_Vacuum ){
/* This INSERT command is part of a VACUUM operation, which guarantees
** that the destination table is empty. If all indexed columns use
** collation sequence BINARY, then it can also be assumed that the
** index will be populated by inserting keys in strictly sorted
** order. In this case, instead of seeking within the b-tree as part
** of every OP_IdxInsert opcode, an OP_SeekEnd is added before the
** OP_IdxInsert to seek to the point within the b-tree where each key
** should be inserted. This is faster.
**
** If any of the indexed columns use a collation sequence other than
** BINARY, this optimization is disabled. This is because the user
** might change the definition of a collation sequence and then run
** a VACUUM command. In that case keys may not be written in strictly
** sorted order. */
for(i=0; i<pSrcIdx->nColumn; i++){
const char *zColl = pSrcIdx->azColl[i];
if( sqlite3_stricmp(sqlite3StrBINARY, zColl) ) break;
}
if( i==pSrcIdx->nColumn ){
idxInsFlags = OPFLAG_USESEEKRESULT;
sqlite3VdbeAddOp1(v, OP_SeekEnd, iDest);
}
}else if( !HasRowid(pSrc) && pDestIdx->idxType==SQLITE_IDXTYPE_PRIMARYKEY ){
idxInsFlags |= OPFLAG_NCHANGE;
}
sqlite3VdbeAddOp3(v, OP_RowData, iSrc, regData, 1);
sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, regData);
sqlite3VdbeChangeP5(v, idxInsFlags|OPFLAG_APPEND);
sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addr1);
sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
}
if( emptySrcTest ) sqlite3VdbeJumpHere(v, emptySrcTest);
sqlite3ReleaseTempReg(pParse, regRowid);
sqlite3ReleaseTempReg(pParse, regData);
if( emptyDestTest ){
sqlite3AutoincrementEnd(pParse);
sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
sqlite3VdbeJumpHere(v, emptyDestTest);
sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
return 0;
}else{
return 1;
}
}
#endif /* SQLITE_OMIT_XFER_OPT */
/************** End of insert.c **********************************************/
/************** Begin file legacy.c ******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** Main file for the SQLite library. The routines in this file
** implement the programmer interface to the library. Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
*/
/* #include "sqliteInt.h" */
/*
** Execute SQL code. Return one of the SQLITE_ success/failure
** codes. Also write an error message into memory obtained from
** malloc() and make *pzErrMsg point to that message.
**
** If the SQL is a query, then for each row in the query result
** the xCallback() function is called. pArg becomes the first
** argument to xCallback(). If xCallback=NULL then no callback
** is invoked, even for queries.
*/
SQLITE_API int SQLITE_APICALL sqlite3_exec(
sqlite3 *db, /* The database on which the SQL executes */
const char *zSql, /* The SQL to be executed */
sqlite3_callback xCallback, /* Invoke this callback routine */
void *pArg, /* First argument to xCallback() */
char **pzErrMsg /* Write error messages here */
){
int rc = SQLITE_OK; /* Return code */
const char *zLeftover; /* Tail of unprocessed SQL */
sqlite3_stmt *pStmt = 0; /* The current SQL statement */
char **azCols = 0; /* Names of result columns */
int callbackIsInit; /* True if callback data is initialized */
if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
if( zSql==0 ) zSql = "";
sqlite3_mutex_enter(db->mutex);
sqlite3Error(db, SQLITE_OK);
while( rc==SQLITE_OK && zSql[0] ){
int nCol = 0;
char **azVals = 0;
pStmt = 0;
rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, &zLeftover);
assert( rc==SQLITE_OK || pStmt==0 );
if( rc!=SQLITE_OK ){
continue;
}
if( !pStmt ){
/* this happens for a comment or white-space */
zSql = zLeftover;
continue;
}
callbackIsInit = 0;
while( 1 ){
int i;
rc = sqlite3_step(pStmt);
/* Invoke the callback function if required */
if( xCallback && (SQLITE_ROW==rc ||
(SQLITE_DONE==rc && !callbackIsInit
&& db->flags&SQLITE_NullCallback)) ){
if( !callbackIsInit ){
nCol = sqlite3_column_count(pStmt);
azCols = sqlite3DbMallocRaw(db, (2*nCol+1)*sizeof(const char*));
if( azCols==0 ){
goto exec_out;
}
for(i=0; i<nCol; i++){
azCols[i] = (char *)sqlite3_column_name(pStmt, i);
/* sqlite3VdbeSetColName() installs column names as UTF8
** strings so there is no way for sqlite3_column_name() to fail. */
assert( azCols[i]!=0 );
}
callbackIsInit = 1;
}
if( rc==SQLITE_ROW ){
azVals = &azCols[nCol];
for(i=0; i<nCol; i++){
azVals[i] = (char *)sqlite3_column_text(pStmt, i);
if( !azVals[i] && sqlite3_column_type(pStmt, i)!=SQLITE_NULL ){
sqlite3OomFault(db);
goto exec_out;
}
}
azVals[i] = 0;
}
if( xCallback(pArg, nCol, azVals, azCols) ){
/* EVIDENCE-OF: R-38229-40159 If the callback function to
** sqlite3_exec() returns non-zero, then sqlite3_exec() will
** return SQLITE_ABORT. */
rc = SQLITE_ABORT;
sqlite3VdbeFinalize((Vdbe *)pStmt);
pStmt = 0;
sqlite3Error(db, SQLITE_ABORT);
goto exec_out;
}
}
if( rc!=SQLITE_ROW ){
rc = sqlite3VdbeFinalize((Vdbe *)pStmt);
pStmt = 0;
zSql = zLeftover;
while( sqlite3Isspace(zSql[0]) ) zSql++;
break;
}
}
sqlite3DbFree(db, azCols);
azCols = 0;
}
exec_out:
if( pStmt ) sqlite3VdbeFinalize((Vdbe *)pStmt);
sqlite3DbFree(db, azCols);
rc = sqlite3ApiExit(db, rc);
if( rc!=SQLITE_OK && pzErrMsg ){
*pzErrMsg = sqlite3DbStrDup(0, sqlite3_errmsg(db));
if( *pzErrMsg==0 ){
rc = SQLITE_NOMEM_BKPT;
sqlite3Error(db, SQLITE_NOMEM);
}
}else if( pzErrMsg ){
*pzErrMsg = 0;
}
assert( (rc&db->errMask)==rc );
sqlite3_mutex_leave(db->mutex);
return rc;
}
/************** End of legacy.c **********************************************/
/************** Begin file loadext.c *****************************************/
/*
** 2006 June 7
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to dynamically load extensions into
** the SQLite library.
*/
#ifndef SQLITE_CORE
#define SQLITE_CORE 1 /* Disable the API redefinition in sqlite3ext.h */
#endif
/************** Include sqlite3ext.h in the middle of loadext.c **************/
/************** Begin file sqlite3ext.h **************************************/
/*
** 2006 June 7
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the SQLite interface for use by
** shared libraries that want to be imported as extensions into
** an SQLite instance. Shared libraries that intend to be loaded
** as extensions by SQLite should #include this file instead of
** sqlite3.h.
*/
#ifndef SQLITE3EXT_H
#define SQLITE3EXT_H
/* #include "sqlite3.h" */
/*
** The following structure holds pointers to all of the SQLite API
** routines.
**
** WARNING: In order to maintain backwards compatibility, add new
** interfaces to the end of this structure only. If you insert new
** interfaces in the middle of this structure, then older different
** versions of SQLite will not be able to load each other's shared
** libraries!
*/
struct sqlite3_api_routines {
void * (SQLITE_APICALL *aggregate_context)(sqlite3_context*,int nBytes);
int (SQLITE_APICALL *aggregate_count)(sqlite3_context*);
int (SQLITE_APICALL *bind_blob)(sqlite3_stmt*,int,const void*,int n,void(SQLITE_CALLBACK *)(void*));
int (SQLITE_APICALL *bind_double)(sqlite3_stmt*,int,double);
int (SQLITE_APICALL *bind_int)(sqlite3_stmt*,int,int);
int (SQLITE_APICALL *bind_int64)(sqlite3_stmt*,int,sqlite_int64);
int (SQLITE_APICALL *bind_null)(sqlite3_stmt*,int);
int (SQLITE_APICALL *bind_parameter_count)(sqlite3_stmt*);
int (SQLITE_APICALL *bind_parameter_index)(sqlite3_stmt*,const char*zName);
const char * (SQLITE_APICALL *bind_parameter_name)(sqlite3_stmt*,int);
int (SQLITE_APICALL *bind_text)(sqlite3_stmt*,int,const char*,int n,void(SQLITE_CALLBACK *)(void*));
int (SQLITE_APICALL *bind_text16)(sqlite3_stmt*,int,const void*,int,void(SQLITE_CALLBACK *)(void*));
int (SQLITE_APICALL *bind_value)(sqlite3_stmt*,int,const sqlite3_value*);
int (SQLITE_APICALL *busy_handler)(sqlite3*,int(SQLITE_CALLBACK *)(void*,int),void*);
int (SQLITE_APICALL *busy_timeout)(sqlite3*,int ms);
int (SQLITE_APICALL *changes)(sqlite3*);
int (SQLITE_APICALL *close)(sqlite3*);
int (SQLITE_APICALL *collation_needed)(sqlite3*,void*,void(SQLITE_CALLBACK *)(void*,sqlite3*,
int eTextRep,const char*));
int (SQLITE_APICALL *collation_needed16)(sqlite3*,void*,void(SQLITE_CALLBACK *)(void*,sqlite3*,
int eTextRep,const void*));
const void * (SQLITE_APICALL *column_blob)(sqlite3_stmt*,int iCol);
int (SQLITE_APICALL *column_bytes)(sqlite3_stmt*,int iCol);
int (SQLITE_APICALL *column_bytes16)(sqlite3_stmt*,int iCol);
int (SQLITE_APICALL *column_count)(sqlite3_stmt*pStmt);
const char * (SQLITE_APICALL *column_database_name)(sqlite3_stmt*,int);
const void * (SQLITE_APICALL *column_database_name16)(sqlite3_stmt*,int);
const char * (SQLITE_APICALL *column_decltype)(sqlite3_stmt*,int i);
const void * (SQLITE_APICALL *column_decltype16)(sqlite3_stmt*,int);
double (SQLITE_APICALL *column_double)(sqlite3_stmt*,int iCol);
int (SQLITE_APICALL *column_int)(sqlite3_stmt*,int iCol);
sqlite_int64 (SQLITE_APICALL *column_int64)(sqlite3_stmt*,int iCol);
const char * (SQLITE_APICALL *column_name)(sqlite3_stmt*,int);
const void * (SQLITE_APICALL *column_name16)(sqlite3_stmt*,int);
const char * (SQLITE_APICALL *column_origin_name)(sqlite3_stmt*,int);
const void * (SQLITE_APICALL *column_origin_name16)(sqlite3_stmt*,int);
const char * (SQLITE_APICALL *column_table_name)(sqlite3_stmt*,int);
const void * (SQLITE_APICALL *column_table_name16)(sqlite3_stmt*,int);
const unsigned char * (SQLITE_APICALL *column_text)(sqlite3_stmt*,int iCol);
const void * (SQLITE_APICALL *column_text16)(sqlite3_stmt*,int iCol);
int (SQLITE_APICALL *column_type)(sqlite3_stmt*,int iCol);
sqlite3_value* (SQLITE_APICALL *column_value)(sqlite3_stmt*,int iCol);
void * (SQLITE_APICALL *commit_hook)(sqlite3*,int(SQLITE_CALLBACK *)(void*),void*);
int (SQLITE_APICALL *complete)(const char*sql);
int (SQLITE_APICALL *complete16)(const void*sql);
int (SQLITE_APICALL *create_collation)(sqlite3*,const char*,int,void*,
int(SQLITE_CALLBACK *)(void*,int,const void*,int,const void*));
int (SQLITE_APICALL *create_collation16)(sqlite3*,const void*,int,void*,
int(SQLITE_CALLBACK *)(void*,int,const void*,int,const void*));
int (SQLITE_APICALL *create_function)(sqlite3*,const char*,int,int,void*,
void (SQLITE_APICALL *xFunc)(sqlite3_context*,int,sqlite3_value**),
void (SQLITE_APICALL *xStep)(sqlite3_context*,int,sqlite3_value**),
void (SQLITE_APICALL *xFinal)(sqlite3_context*));
int (SQLITE_APICALL *create_function16)(sqlite3*,const void*,int,int,void*,
void (SQLITE_APICALL *xFunc)(sqlite3_context*,int,sqlite3_value**),
void (SQLITE_APICALL *xStep)(sqlite3_context*,int,sqlite3_value**),
void (SQLITE_APICALL *xFinal)(sqlite3_context*));
int (SQLITE_APICALL *create_module)(sqlite3*,const char*,const sqlite3_module*,void*);
int (SQLITE_APICALL *data_count)(sqlite3_stmt*pStmt);
sqlite3 * (SQLITE_APICALL *db_handle)(sqlite3_stmt*);
int (SQLITE_APICALL *declare_vtab)(sqlite3*,const char*);
int (SQLITE_APICALL *enable_shared_cache)(int);
int (SQLITE_APICALL *errcode)(sqlite3*db);
const char * (SQLITE_APICALL *errmsg)(sqlite3*);
const void * (SQLITE_APICALL *errmsg16)(sqlite3*);
int (SQLITE_APICALL *exec)(sqlite3*,const char*,sqlite3_callback,void*,char**);
int (SQLITE_APICALL *expired)(sqlite3_stmt*);
int (SQLITE_APICALL *finalize)(sqlite3_stmt*pStmt);
void (SQLITE_APICALL *free)(void*);
void (SQLITE_APICALL *free_table)(char**result);
int (SQLITE_APICALL *get_autocommit)(sqlite3*);
void * (SQLITE_APICALL *get_auxdata)(sqlite3_context*,int);
int (SQLITE_APICALL *get_table)(sqlite3*,const char*,char***,int*,int*,char**);
int (SQLITE_APICALL *global_recover)(void);
void (SQLITE_APICALL *interruptx)(sqlite3*);
sqlite_int64 (SQLITE_APICALL *last_insert_rowid)(sqlite3*);
const char * (SQLITE_APICALL *libversion)(void);
int (SQLITE_APICALL *libversion_number)(void);
void *(SQLITE_APICALL *malloc)(int);
char * (SQLITE_APICALL *mprintf)(const char*,...);
int (SQLITE_APICALL *open)(const char*,sqlite3**);
int (SQLITE_APICALL *open16)(const void*,sqlite3**);
int (SQLITE_APICALL *prepare)(sqlite3*,const char*,int,sqlite3_stmt**,const char**);
int (SQLITE_APICALL *prepare16)(sqlite3*,const void*,int,sqlite3_stmt**,const void**);
void * (SQLITE_APICALL *profile)(sqlite3*,void(SQLITE_CALLBACK *)(void*,const char*,sqlite_uint64),void*);
void (SQLITE_APICALL *progress_handler)(sqlite3*,int,int(SQLITE_CALLBACK *)(void*),void*);
void *(SQLITE_APICALL *realloc)(void*,int);
int (SQLITE_APICALL *reset)(sqlite3_stmt*pStmt);
void (SQLITE_APICALL *result_blob)(sqlite3_context*,const void*,int,void(SQLITE_CALLBACK *)(void*));
void (SQLITE_APICALL *result_double)(sqlite3_context*,double);
void (SQLITE_APICALL *result_error)(sqlite3_context*,const char*,int);
void (SQLITE_APICALL *result_error16)(sqlite3_context*,const void*,int);
void (SQLITE_APICALL *result_int)(sqlite3_context*,int);
void (SQLITE_APICALL *result_int64)(sqlite3_context*,sqlite_int64);
void (SQLITE_APICALL *result_null)(sqlite3_context*);
void (SQLITE_APICALL *result_text)(sqlite3_context*,const char*,int,void(SQLITE_CALLBACK *)(void*));
void (SQLITE_APICALL *result_text16)(sqlite3_context*,const void*,int,void(SQLITE_CALLBACK *)(void*));
void (SQLITE_APICALL *result_text16be)(sqlite3_context*,const void*,int,void(SQLITE_CALLBACK *)(void*));
void (SQLITE_APICALL *result_text16le)(sqlite3_context*,const void*,int,void(SQLITE_CALLBACK *)(void*));
void (SQLITE_APICALL *result_value)(sqlite3_context*,sqlite3_value*);
void * (SQLITE_APICALL *rollback_hook)(sqlite3*,void(SQLITE_CALLBACK *)(void*),void*);
int (SQLITE_APICALL *set_authorizer)(sqlite3*,int(SQLITE_CALLBACK *)(void*,int,const char*,const char*,
const char*,const char*),void*);
void (SQLITE_APICALL *set_auxdata)(sqlite3_context*,int,void*,void (SQLITE_CALLBACK *)(void*));
char * (SQLITE_APICALL *xsnprintf)(int,char*,const char*,...);
int (SQLITE_APICALL *step)(sqlite3_stmt*);
int (SQLITE_APICALL *table_column_metadata)(sqlite3*,const char*,const char*,const char*,
char const**,char const**,int*,int*,int*);
void (SQLITE_APICALL *thread_cleanup)(void);
int (SQLITE_APICALL *total_changes)(sqlite3*);
void * (SQLITE_APICALL *trace)(sqlite3*,void(SQLITE_APICALL *xTrace)(void*,const char*),void*);
int (SQLITE_APICALL *transfer_bindings)(sqlite3_stmt*,sqlite3_stmt*);
void * (SQLITE_APICALL *update_hook)(sqlite3*,void(SQLITE_CALLBACK *)(void*,int ,char const*,char const*,
sqlite_int64),void*);
void * (SQLITE_APICALL *user_data)(sqlite3_context*);
const void * (SQLITE_APICALL *value_blob)(sqlite3_value*);
int (SQLITE_APICALL *value_bytes)(sqlite3_value*);
int (SQLITE_APICALL *value_bytes16)(sqlite3_value*);
double (SQLITE_APICALL *value_double)(sqlite3_value*);
int (SQLITE_APICALL *value_int)(sqlite3_value*);
sqlite_int64 (SQLITE_APICALL *value_int64)(sqlite3_value*);
int (SQLITE_APICALL *value_numeric_type)(sqlite3_value*);
const unsigned char * (SQLITE_APICALL *value_text)(sqlite3_value*);
const void * (SQLITE_APICALL *value_text16)(sqlite3_value*);
const void * (SQLITE_APICALL *value_text16be)(sqlite3_value*);
const void * (SQLITE_APICALL *value_text16le)(sqlite3_value*);
int (SQLITE_APICALL *value_type)(sqlite3_value*);
char *(SQLITE_APICALL *vmprintf)(const char*,va_list);
/* Added ??? */
int (SQLITE_APICALL *overload_function)(sqlite3*, const char *zFuncName, int nArg);
/* Added by 3.3.13 */
int (SQLITE_APICALL *prepare_v2)(sqlite3*,const char*,int,sqlite3_stmt**,const char**);
int (SQLITE_APICALL *prepare16_v2)(sqlite3*,const void*,int,sqlite3_stmt**,const void**);
int (SQLITE_APICALL *clear_bindings)(sqlite3_stmt*);
/* Added by 3.4.1 */
int (SQLITE_APICALL *create_module_v2)(sqlite3*,const char*,const sqlite3_module*,void*,
void (SQLITE_APICALL *xDestroy)(void *));
/* Added by 3.5.0 */
int (SQLITE_APICALL *bind_zeroblob)(sqlite3_stmt*,int,int);
int (SQLITE_APICALL *blob_bytes)(sqlite3_blob*);
int (SQLITE_APICALL *blob_close)(sqlite3_blob*);
int (SQLITE_APICALL *blob_open)(sqlite3*,const char*,const char*,const char*,sqlite3_int64,
int,sqlite3_blob**);
int (SQLITE_APICALL *blob_read)(sqlite3_blob*,void*,int,int);
int (SQLITE_APICALL *blob_write)(sqlite3_blob*,const void*,int,int);
int (SQLITE_APICALL *create_collation_v2)(sqlite3*,const char*,int,void*,
int(SQLITE_CALLBACK *)(void*,int,const void*,int,const void*),
void(SQLITE_CALLBACK *)(void*));
int (SQLITE_APICALL *file_control)(sqlite3*,const char*,int,void*);
sqlite3_int64 (SQLITE_APICALL *memory_highwater)(int);
sqlite3_int64 (SQLITE_APICALL *memory_used)(void);
sqlite3_mutex *(SQLITE_APICALL *mutex_alloc)(int);
void (SQLITE_APICALL *mutex_enter)(sqlite3_mutex*);
void (SQLITE_APICALL *mutex_free)(sqlite3_mutex*);
void (SQLITE_APICALL *mutex_leave)(sqlite3_mutex*);
int (SQLITE_APICALL *mutex_try)(sqlite3_mutex*);
int (SQLITE_APICALL *open_v2)(const char*,sqlite3**,int,const char*);
int (SQLITE_APICALL *release_memory)(int);
void (SQLITE_APICALL *result_error_nomem)(sqlite3_context*);
void (SQLITE_APICALL *result_error_toobig)(sqlite3_context*);
int (SQLITE_APICALL *sleep)(int);
void (SQLITE_APICALL *soft_heap_limit)(int);
sqlite3_vfs *(SQLITE_APICALL *vfs_find)(const char*);
int (SQLITE_APICALL *vfs_register)(sqlite3_vfs*,int);
int (SQLITE_APICALL *vfs_unregister)(sqlite3_vfs*);
int (SQLITE_APICALL *xthreadsafe)(void);
void (SQLITE_APICALL *result_zeroblob)(sqlite3_context*,int);
void (SQLITE_APICALL *result_error_code)(sqlite3_context*,int);
int (SQLITE_APICALL *test_control)(int, ...);
void (SQLITE_APICALL *randomness)(int,void*);
sqlite3 *(SQLITE_APICALL *context_db_handle)(sqlite3_context*);
int (SQLITE_APICALL *extended_result_codes)(sqlite3*,int);
int (SQLITE_APICALL *limit)(sqlite3*,int,int);
sqlite3_stmt *(SQLITE_APICALL *next_stmt)(sqlite3*,sqlite3_stmt*);
const char *(SQLITE_APICALL *sql)(sqlite3_stmt*);
int (SQLITE_APICALL *status)(int,int*,int*,int);
int (SQLITE_APICALL *backup_finish)(sqlite3_backup*);
sqlite3_backup *(SQLITE_APICALL *backup_init)(sqlite3*,const char*,sqlite3*,const char*);
int (SQLITE_APICALL *backup_pagecount)(sqlite3_backup*);
int (SQLITE_APICALL *backup_remaining)(sqlite3_backup*);
int (SQLITE_APICALL *backup_step)(sqlite3_backup*,int);
const char *(SQLITE_APICALL *compileoption_get)(int);
int (SQLITE_APICALL *compileoption_used)(const char*);
int (SQLITE_APICALL *create_function_v2)(sqlite3*,const char*,int,int,void*,
void (SQLITE_APICALL *xFunc)(sqlite3_context*,int,sqlite3_value**),
void (SQLITE_APICALL *xStep)(sqlite3_context*,int,sqlite3_value**),
void (SQLITE_APICALL *xFinal)(sqlite3_context*),
void(SQLITE_APICALL *xDestroy)(void*));
int (SQLITE_APICALL *db_config)(sqlite3*,int,...);
sqlite3_mutex *(SQLITE_APICALL *db_mutex)(sqlite3*);
int (SQLITE_APICALL *db_status)(sqlite3*,int,int*,int*,int);
int (SQLITE_APICALL *extended_errcode)(sqlite3*);
void (SQLITE_APICALL *log)(int,const char*,...);
sqlite3_int64 (SQLITE_APICALL *soft_heap_limit64)(sqlite3_int64);
const char *(SQLITE_APICALL *sourceid)(void);
int (SQLITE_APICALL *stmt_status)(sqlite3_stmt*,int,int);
int (SQLITE_APICALL *strnicmp)(const char*,const char*,int);
int (SQLITE_APICALL *unlock_notify)(sqlite3*,void(SQLITE_CALLBACK *)(void**,int),void*);
int (SQLITE_APICALL *wal_autocheckpoint)(sqlite3*,int);
int (SQLITE_APICALL *wal_checkpoint)(sqlite3*,const char*);
void *(SQLITE_APICALL *wal_hook)(sqlite3*,int(SQLITE_CALLBACK *)(void*,sqlite3*,const char*,int),void*);
int (SQLITE_APICALL *blob_reopen)(sqlite3_blob*,sqlite3_int64);
int (SQLITE_APICALL *vtab_config)(sqlite3*,int op,...);
int (SQLITE_APICALL *vtab_on_conflict)(sqlite3*);
/* Version 3.7.16 and later */
int (SQLITE_APICALL *close_v2)(sqlite3*);
const char *(SQLITE_APICALL *db_filename)(sqlite3*,const char*);
int (SQLITE_APICALL *db_readonly)(sqlite3*,const char*);
int (SQLITE_APICALL *db_release_memory)(sqlite3*);
const char *(SQLITE_APICALL *errstr)(int);
int (SQLITE_APICALL *stmt_busy)(sqlite3_stmt*);
int (SQLITE_APICALL *stmt_readonly)(sqlite3_stmt*);
int (SQLITE_APICALL *stricmp)(const char*,const char*);
int (SQLITE_APICALL *uri_boolean)(const char*,const char*,int);
sqlite3_int64 (SQLITE_APICALL *uri_int64)(const char*,const char*,sqlite3_int64);
const char *(SQLITE_APICALL *uri_parameter)(const char*,const char*);
char *(SQLITE_APICALL *xvsnprintf)(int,char*,const char*,va_list);
int (SQLITE_APICALL *wal_checkpoint_v2)(sqlite3*,const char*,int,int*,int*);
/* Version 3.8.7 and later */
int (SQLITE_APICALL *auto_extension)(void(SQLITE_CALLBACK *)(void));
int (SQLITE_APICALL *bind_blob64)(sqlite3_stmt*,int,const void*,sqlite3_uint64,
void(SQLITE_CALLBACK *)(void*));
int (SQLITE_APICALL *bind_text64)(sqlite3_stmt*,int,const char*,sqlite3_uint64,
void(SQLITE_CALLBACK *)(void*),unsigned char);
int (SQLITE_APICALL *cancel_auto_extension)(void(SQLITE_CALLBACK *)(void));
int (SQLITE_APICALL *load_extension)(sqlite3*,const char*,const char*,char**);
void *(SQLITE_APICALL *malloc64)(sqlite3_uint64);
sqlite3_uint64 (SQLITE_APICALL *msize)(void*);
void *(SQLITE_APICALL *realloc64)(void*,sqlite3_uint64);
void (SQLITE_APICALL *reset_auto_extension)(void);
void (SQLITE_APICALL *result_blob64)(sqlite3_context*,const void*,sqlite3_uint64,
void(SQLITE_CALLBACK *)(void*));
void (SQLITE_APICALL *result_text64)(sqlite3_context*,const char*,sqlite3_uint64,
void(SQLITE_CALLBACK *)(void*), unsigned char);
int (SQLITE_APICALL *strglob)(const char*,const char*);
/* Version 3.8.11 and later */
sqlite3_value *(SQLITE_APICALL *value_dup)(const sqlite3_value*);
void (SQLITE_APICALL *value_free)(sqlite3_value*);
int (SQLITE_APICALL *result_zeroblob64)(sqlite3_context*,sqlite3_uint64);
int (SQLITE_APICALL *bind_zeroblob64)(sqlite3_stmt*, int, sqlite3_uint64);
/* Version 3.9.0 and later */
unsigned int (SQLITE_APICALL *value_subtype)(sqlite3_value*);
void (SQLITE_APICALL *result_subtype)(sqlite3_context*,unsigned int);
/* Version 3.10.0 and later */
int (SQLITE_APICALL *status64)(int,sqlite3_int64*,sqlite3_int64*,int);
int (SQLITE_APICALL *strlike)(const char*,const char*,unsigned int);
int (SQLITE_APICALL *db_cacheflush)(sqlite3*);
/* Version 3.12.0 and later */
int (SQLITE_APICALL *system_errno)(sqlite3*);
/* Version 3.14.0 and later */
int (SQLITE_APICALL *trace_v2)(sqlite3*,unsigned,int(SQLITE_CALLBACK *)(unsigned,void*,void*,void*),void*);
char *(SQLITE_APICALL *expanded_sql)(sqlite3_stmt*);
/* Version 3.18.0 and later */
void (SQLITE_APICALL *set_last_insert_rowid)(sqlite3*,sqlite3_int64);
/* Version 3.20.0 and later */
int (SQLITE_APICALL *prepare_v3)(sqlite3*,const char*,int,unsigned int,
sqlite3_stmt**,const char**);
int (SQLITE_APICALL *prepare16_v3)(sqlite3*,const void*,int,unsigned int,
sqlite3_stmt**,const void**);
int (SQLITE_APICALL *bind_pointer)(sqlite3_stmt*,int,void*,const char*,void(SQLITE_CALLBACK *)(void*));
void (SQLITE_APICALL *result_pointer)(sqlite3_context*,void*,const char*,void(SQLITE_CALLBACK *)(void*));
void *(SQLITE_APICALL *value_pointer)(sqlite3_value*,const char*);
int (SQLITE_APICALL *vtab_nochange)(sqlite3_context*);
int (SQLITE_APICALL *value_nochange)(sqlite3_value*);
const char *(SQLITE_APICALL *vtab_collation)(sqlite3_index_info*,int);
/* Version 3.24.0 and later */
int (SQLITE_APICALL *keyword_count)(void);
int (SQLITE_APICALL *keyword_name)(int,const char**,int*);
int (SQLITE_APICALL *keyword_check)(const char*,int);
sqlite3_str *(SQLITE_APICALL *str_new)(sqlite3*);
char *(SQLITE_APICALL *str_finish)(sqlite3_str*);
void (SQLITE_APICALL *str_appendf)(sqlite3_str*, const char *zFormat, ...);
void (SQLITE_APICALL *str_vappendf)(sqlite3_str*, const char *zFormat, va_list);
void (SQLITE_APICALL *str_append)(sqlite3_str*, const char *zIn, int N);
void (SQLITE_APICALL *str_appendall)(sqlite3_str*, const char *zIn);
void (SQLITE_APICALL *str_appendchar)(sqlite3_str*, int N, char C);
void (SQLITE_APICALL *str_reset)(sqlite3_str*);
int (SQLITE_APICALL *str_errcode)(sqlite3_str*);
int (SQLITE_APICALL *str_length)(sqlite3_str*);
char *(SQLITE_APICALL *str_value)(sqlite3_str*);
/* Version 3.25.0 and later */
int (SQLITE_APICALL *create_window_function)(sqlite3*,const char*,int,int,void*,
void (SQLITE_APICALL *xStep)(sqlite3_context*,int,sqlite3_value**),
void (SQLITE_APICALL *xFinal)(sqlite3_context*),
void (SQLITE_APICALL *xValue)(sqlite3_context*),
void (SQLITE_APICALL *xInv)(sqlite3_context*,int,sqlite3_value**),
void(SQLITE_APICALL *xDestroy)(void*));
/* Version 3.26.0 and later */
const char *(SQLITE_APICALL *normalized_sql)(sqlite3_stmt*);
/* Version 3.28.0 and later */
int (SQLITE_APICALL *stmt_isexplain)(sqlite3_stmt*);
int (SQLITE_APICALL *value_frombind)(sqlite3_value*);
/* Version 3.30.0 and later */
int (SQLITE_APICALL *drop_modules)(sqlite3*,const char**);
/* Version 3.31.0 and later */
sqlite3_int64 (SQLITE_APICALL *hard_heap_limit64)(sqlite3_int64);
const char *(SQLITE_APICALL *uri_key)(const char*,int);
const char *(SQLITE_APICALL *filename_database)(const char*);
const char *(SQLITE_APICALL *filename_journal)(const char*);
const char *(SQLITE_APICALL *filename_wal)(const char*);
/* Version 3.32.0 and later */
char *(SQLITE_APICALL *create_filename)(const char*,const char*,const char*,
int,const char**);
void (SQLITE_APICALL *free_filename)(char*);
sqlite3_file *(SQLITE_APICALL *database_file_object)(const char*);
/* Version 3.34.0 and later */
int (SQLITE_APICALL *txn_state)(sqlite3*,const char*);
};
/*
** This is the function signature used for all extension entry points. It
** is also defined in the file "loadext.c".
*/
typedef int (SQLITE_APICALL *sqlite3_loadext_entry)(
sqlite3 *db, /* Handle to the database. */
char **pzErrMsg, /* Used to set error string on failure. */
const sqlite3_api_routines *pThunk /* Extension API function pointers. */
);
/*
** The following macros redefine the API routines so that they are
** redirected through the global sqlite3_api structure.
**
** This header file is also used by the loadext.c source file
** (part of the main SQLite library - not an extension) so that
** it can get access to the sqlite3_api_routines structure
** definition. But the main library does not want to redefine
** the API. So the redefinition macros are only valid if the
** SQLITE_CORE macros is undefined.
*/
#if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
#define sqlite3_aggregate_context sqlite3_api->aggregate_context
#ifndef SQLITE_OMIT_DEPRECATED
#define sqlite3_aggregate_count sqlite3_api->aggregate_count
#endif
#define sqlite3_bind_blob sqlite3_api->bind_blob
#define sqlite3_bind_double sqlite3_api->bind_double
#define sqlite3_bind_int sqlite3_api->bind_int
#define sqlite3_bind_int64 sqlite3_api->bind_int64
#define sqlite3_bind_null sqlite3_api->bind_null
#define sqlite3_bind_parameter_count sqlite3_api->bind_parameter_count
#define sqlite3_bind_parameter_index sqlite3_api->bind_parameter_index
#define sqlite3_bind_parameter_name sqlite3_api->bind_parameter_name
#define sqlite3_bind_text sqlite3_api->bind_text
#define sqlite3_bind_text16 sqlite3_api->bind_text16
#define sqlite3_bind_value sqlite3_api->bind_value
#define sqlite3_busy_handler sqlite3_api->busy_handler
#define sqlite3_busy_timeout sqlite3_api->busy_timeout
#define sqlite3_changes sqlite3_api->changes
#define sqlite3_close sqlite3_api->close
#define sqlite3_collation_needed sqlite3_api->collation_needed
#define sqlite3_collation_needed16 sqlite3_api->collation_needed16
#define sqlite3_column_blob sqlite3_api->column_blob
#define sqlite3_column_bytes sqlite3_api->column_bytes
#define sqlite3_column_bytes16 sqlite3_api->column_bytes16
#define sqlite3_column_count sqlite3_api->column_count
#define sqlite3_column_database_name sqlite3_api->column_database_name
#define sqlite3_column_database_name16 sqlite3_api->column_database_name16
#define sqlite3_column_decltype sqlite3_api->column_decltype
#define sqlite3_column_decltype16 sqlite3_api->column_decltype16
#define sqlite3_column_double sqlite3_api->column_double
#define sqlite3_column_int sqlite3_api->column_int
#define sqlite3_column_int64 sqlite3_api->column_int64
#define sqlite3_column_name sqlite3_api->column_name
#define sqlite3_column_name16 sqlite3_api->column_name16
#define sqlite3_column_origin_name sqlite3_api->column_origin_name
#define sqlite3_column_origin_name16 sqlite3_api->column_origin_name16
#define sqlite3_column_table_name sqlite3_api->column_table_name
#define sqlite3_column_table_name16 sqlite3_api->column_table_name16
#define sqlite3_column_text sqlite3_api->column_text
#define sqlite3_column_text16 sqlite3_api->column_text16
#define sqlite3_column_type sqlite3_api->column_type
#define sqlite3_column_value sqlite3_api->column_value
#define sqlite3_commit_hook sqlite3_api->commit_hook
#define sqlite3_complete sqlite3_api->complete
#define sqlite3_complete16 sqlite3_api->complete16
#define sqlite3_create_collation sqlite3_api->create_collation
#define sqlite3_create_collation16 sqlite3_api->create_collation16
#define sqlite3_create_function sqlite3_api->create_function
#define sqlite3_create_function16 sqlite3_api->create_function16
#define sqlite3_create_module sqlite3_api->create_module
#define sqlite3_create_module_v2 sqlite3_api->create_module_v2
#define sqlite3_data_count sqlite3_api->data_count
#define sqlite3_db_handle sqlite3_api->db_handle
#define sqlite3_declare_vtab sqlite3_api->declare_vtab
#define sqlite3_enable_shared_cache sqlite3_api->enable_shared_cache
#define sqlite3_errcode sqlite3_api->errcode
#define sqlite3_errmsg sqlite3_api->errmsg
#define sqlite3_errmsg16 sqlite3_api->errmsg16
#define sqlite3_exec sqlite3_api->exec
#ifndef SQLITE_OMIT_DEPRECATED
#define sqlite3_expired sqlite3_api->expired
#endif
#define sqlite3_finalize sqlite3_api->finalize
#define sqlite3_free sqlite3_api->free
#define sqlite3_free_table sqlite3_api->free_table
#define sqlite3_get_autocommit sqlite3_api->get_autocommit
#define sqlite3_get_auxdata sqlite3_api->get_auxdata
#define sqlite3_get_table sqlite3_api->get_table
#ifndef SQLITE_OMIT_DEPRECATED
#define sqlite3_global_recover sqlite3_api->global_recover
#endif
#define sqlite3_interrupt sqlite3_api->interruptx
#define sqlite3_last_insert_rowid sqlite3_api->last_insert_rowid
#define sqlite3_libversion sqlite3_api->libversion
#define sqlite3_libversion_number sqlite3_api->libversion_number
#define sqlite3_malloc sqlite3_api->malloc
#define sqlite3_mprintf sqlite3_api->mprintf
#define sqlite3_open sqlite3_api->open
#define sqlite3_open16 sqlite3_api->open16
#define sqlite3_prepare sqlite3_api->prepare
#define sqlite3_prepare16 sqlite3_api->prepare16
#define sqlite3_prepare_v2 sqlite3_api->prepare_v2
#define sqlite3_prepare16_v2 sqlite3_api->prepare16_v2
#define sqlite3_profile sqlite3_api->profile
#define sqlite3_progress_handler sqlite3_api->progress_handler
#define sqlite3_realloc sqlite3_api->realloc
#define sqlite3_reset sqlite3_api->reset
#define sqlite3_result_blob sqlite3_api->result_blob
#define sqlite3_result_double sqlite3_api->result_double
#define sqlite3_result_error sqlite3_api->result_error
#define sqlite3_result_error16 sqlite3_api->result_error16
#define sqlite3_result_int sqlite3_api->result_int
#define sqlite3_result_int64 sqlite3_api->result_int64
#define sqlite3_result_null sqlite3_api->result_null
#define sqlite3_result_text sqlite3_api->result_text
#define sqlite3_result_text16 sqlite3_api->result_text16
#define sqlite3_result_text16be sqlite3_api->result_text16be
#define sqlite3_result_text16le sqlite3_api->result_text16le
#define sqlite3_result_value sqlite3_api->result_value
#define sqlite3_rollback_hook sqlite3_api->rollback_hook
#define sqlite3_set_authorizer sqlite3_api->set_authorizer
#define sqlite3_set_auxdata sqlite3_api->set_auxdata
#define sqlite3_snprintf sqlite3_api->xsnprintf
#define sqlite3_step sqlite3_api->step
#define sqlite3_table_column_metadata sqlite3_api->table_column_metadata
#define sqlite3_thread_cleanup sqlite3_api->thread_cleanup
#define sqlite3_total_changes sqlite3_api->total_changes
#define sqlite3_trace sqlite3_api->trace
#ifndef SQLITE_OMIT_DEPRECATED
#define sqlite3_transfer_bindings sqlite3_api->transfer_bindings
#endif
#define sqlite3_update_hook sqlite3_api->update_hook
#define sqlite3_user_data sqlite3_api->user_data
#define sqlite3_value_blob sqlite3_api->value_blob
#define sqlite3_value_bytes sqlite3_api->value_bytes
#define sqlite3_value_bytes16 sqlite3_api->value_bytes16
#define sqlite3_value_double sqlite3_api->value_double
#define sqlite3_value_int sqlite3_api->value_int
#define sqlite3_value_int64 sqlite3_api->value_int64
#define sqlite3_value_numeric_type sqlite3_api->value_numeric_type
#define sqlite3_value_text sqlite3_api->value_text
#define sqlite3_value_text16 sqlite3_api->value_text16
#define sqlite3_value_text16be sqlite3_api->value_text16be
#define sqlite3_value_text16le sqlite3_api->value_text16le
#define sqlite3_value_type sqlite3_api->value_type
#define sqlite3_vmprintf sqlite3_api->vmprintf
#define sqlite3_vsnprintf sqlite3_api->xvsnprintf
#define sqlite3_overload_function sqlite3_api->overload_function
#define sqlite3_prepare_v2 sqlite3_api->prepare_v2
#define sqlite3_prepare16_v2 sqlite3_api->prepare16_v2
#define sqlite3_clear_bindings sqlite3_api->clear_bindings
#define sqlite3_bind_zeroblob sqlite3_api->bind_zeroblob
#define sqlite3_blob_bytes sqlite3_api->blob_bytes
#define sqlite3_blob_close sqlite3_api->blob_close
#define sqlite3_blob_open sqlite3_api->blob_open
#define sqlite3_blob_read sqlite3_api->blob_read
#define sqlite3_blob_write sqlite3_api->blob_write
#define sqlite3_create_collation_v2 sqlite3_api->create_collation_v2
#define sqlite3_file_control sqlite3_api->file_control
#define sqlite3_memory_highwater sqlite3_api->memory_highwater
#define sqlite3_memory_used sqlite3_api->memory_used
#define sqlite3_mutex_alloc sqlite3_api->mutex_alloc
#define sqlite3_mutex_enter sqlite3_api->mutex_enter
#define sqlite3_mutex_free sqlite3_api->mutex_free
#define sqlite3_mutex_leave sqlite3_api->mutex_leave
#define sqlite3_mutex_try sqlite3_api->mutex_try
#define sqlite3_open_v2 sqlite3_api->open_v2
#define sqlite3_release_memory sqlite3_api->release_memory
#define sqlite3_result_error_nomem sqlite3_api->result_error_nomem
#define sqlite3_result_error_toobig sqlite3_api->result_error_toobig
#define sqlite3_sleep sqlite3_api->sleep
#define sqlite3_soft_heap_limit sqlite3_api->soft_heap_limit
#define sqlite3_vfs_find sqlite3_api->vfs_find
#define sqlite3_vfs_register sqlite3_api->vfs_register
#define sqlite3_vfs_unregister sqlite3_api->vfs_unregister
#define sqlite3_threadsafe sqlite3_api->xthreadsafe
#define sqlite3_result_zeroblob sqlite3_api->result_zeroblob
#define sqlite3_result_error_code sqlite3_api->result_error_code
#define sqlite3_test_control sqlite3_api->test_control
#define sqlite3_randomness sqlite3_api->randomness
#define sqlite3_context_db_handle sqlite3_api->context_db_handle
#define sqlite3_extended_result_codes sqlite3_api->extended_result_codes
#define sqlite3_limit sqlite3_api->limit
#define sqlite3_next_stmt sqlite3_api->next_stmt
#define sqlite3_sql sqlite3_api->sql
#define sqlite3_status sqlite3_api->status
#define sqlite3_backup_finish sqlite3_api->backup_finish
#define sqlite3_backup_init sqlite3_api->backup_init
#define sqlite3_backup_pagecount sqlite3_api->backup_pagecount
#define sqlite3_backup_remaining sqlite3_api->backup_remaining
#define sqlite3_backup_step sqlite3_api->backup_step
#define sqlite3_compileoption_get sqlite3_api->compileoption_get
#define sqlite3_compileoption_used sqlite3_api->compileoption_used
#define sqlite3_create_function_v2 sqlite3_api->create_function_v2
#define sqlite3_db_config sqlite3_api->db_config
#define sqlite3_db_mutex sqlite3_api->db_mutex
#define sqlite3_db_status sqlite3_api->db_status
#define sqlite3_extended_errcode sqlite3_api->extended_errcode
#define sqlite3_log sqlite3_api->log
#define sqlite3_soft_heap_limit64 sqlite3_api->soft_heap_limit64
#define sqlite3_sourceid sqlite3_api->sourceid
#define sqlite3_stmt_status sqlite3_api->stmt_status
#define sqlite3_strnicmp sqlite3_api->strnicmp
#define sqlite3_unlock_notify sqlite3_api->unlock_notify
#define sqlite3_wal_autocheckpoint sqlite3_api->wal_autocheckpoint
#define sqlite3_wal_checkpoint sqlite3_api->wal_checkpoint
#define sqlite3_wal_hook sqlite3_api->wal_hook
#define sqlite3_blob_reopen sqlite3_api->blob_reopen
#define sqlite3_vtab_config sqlite3_api->vtab_config
#define sqlite3_vtab_on_conflict sqlite3_api->vtab_on_conflict
/* Version 3.7.16 and later */
#define sqlite3_close_v2 sqlite3_api->close_v2
#define sqlite3_db_filename sqlite3_api->db_filename
#define sqlite3_db_readonly sqlite3_api->db_readonly
#define sqlite3_db_release_memory sqlite3_api->db_release_memory
#define sqlite3_errstr sqlite3_api->errstr
#define sqlite3_stmt_busy sqlite3_api->stmt_busy
#define sqlite3_stmt_readonly sqlite3_api->stmt_readonly
#define sqlite3_stricmp sqlite3_api->stricmp
#define sqlite3_uri_boolean sqlite3_api->uri_boolean
#define sqlite3_uri_int64 sqlite3_api->uri_int64
#define sqlite3_uri_parameter sqlite3_api->uri_parameter
#define sqlite3_uri_vsnprintf sqlite3_api->xvsnprintf
#define sqlite3_wal_checkpoint_v2 sqlite3_api->wal_checkpoint_v2
/* Version 3.8.7 and later */
#define sqlite3_auto_extension sqlite3_api->auto_extension
#define sqlite3_bind_blob64 sqlite3_api->bind_blob64
#define sqlite3_bind_text64 sqlite3_api->bind_text64
#define sqlite3_cancel_auto_extension sqlite3_api->cancel_auto_extension
#define sqlite3_load_extension sqlite3_api->load_extension
#define sqlite3_malloc64 sqlite3_api->malloc64
#define sqlite3_msize sqlite3_api->msize
#define sqlite3_realloc64 sqlite3_api->realloc64
#define sqlite3_reset_auto_extension sqlite3_api->reset_auto_extension
#define sqlite3_result_blob64 sqlite3_api->result_blob64
#define sqlite3_result_text64 sqlite3_api->result_text64
#define sqlite3_strglob sqlite3_api->strglob
/* Version 3.8.11 and later */
#define sqlite3_value_dup sqlite3_api->value_dup
#define sqlite3_value_free sqlite3_api->value_free
#define sqlite3_result_zeroblob64 sqlite3_api->result_zeroblob64
#define sqlite3_bind_zeroblob64 sqlite3_api->bind_zeroblob64
/* Version 3.9.0 and later */
#define sqlite3_value_subtype sqlite3_api->value_subtype
#define sqlite3_result_subtype sqlite3_api->result_subtype
/* Version 3.10.0 and later */
#define sqlite3_status64 sqlite3_api->status64
#define sqlite3_strlike sqlite3_api->strlike
#define sqlite3_db_cacheflush sqlite3_api->db_cacheflush
/* Version 3.12.0 and later */
#define sqlite3_system_errno sqlite3_api->system_errno
/* Version 3.14.0 and later */
#define sqlite3_trace_v2 sqlite3_api->trace_v2
#define sqlite3_expanded_sql sqlite3_api->expanded_sql
/* Version 3.18.0 and later */
#define sqlite3_set_last_insert_rowid sqlite3_api->set_last_insert_rowid
/* Version 3.20.0 and later */
#define sqlite3_prepare_v3 sqlite3_api->prepare_v3
#define sqlite3_prepare16_v3 sqlite3_api->prepare16_v3
#define sqlite3_bind_pointer sqlite3_api->bind_pointer
#define sqlite3_result_pointer sqlite3_api->result_pointer
#define sqlite3_value_pointer sqlite3_api->value_pointer
/* Version 3.22.0 and later */
#define sqlite3_vtab_nochange sqlite3_api->vtab_nochange
#define sqlite3_value_nochange sqlite3_api->value_nochange
#define sqlite3_vtab_collation sqlite3_api->vtab_collation
/* Version 3.24.0 and later */
#define sqlite3_keyword_count sqlite3_api->keyword_count
#define sqlite3_keyword_name sqlite3_api->keyword_name
#define sqlite3_keyword_check sqlite3_api->keyword_check
#define sqlite3_str_new sqlite3_api->str_new
#define sqlite3_str_finish sqlite3_api->str_finish
#define sqlite3_str_appendf sqlite3_api->str_appendf
#define sqlite3_str_vappendf sqlite3_api->str_vappendf
#define sqlite3_str_append sqlite3_api->str_append
#define sqlite3_str_appendall sqlite3_api->str_appendall
#define sqlite3_str_appendchar sqlite3_api->str_appendchar
#define sqlite3_str_reset sqlite3_api->str_reset
#define sqlite3_str_errcode sqlite3_api->str_errcode
#define sqlite3_str_length sqlite3_api->str_length
#define sqlite3_str_value sqlite3_api->str_value
/* Version 3.25.0 and later */
#define sqlite3_create_window_function sqlite3_api->create_window_function
/* Version 3.26.0 and later */
#define sqlite3_normalized_sql sqlite3_api->normalized_sql
/* Version 3.28.0 and later */
#define sqlite3_stmt_isexplain sqlite3_api->stmt_isexplain
#define sqlite3_value_frombind sqlite3_api->value_frombind
/* Version 3.30.0 and later */
#define sqlite3_drop_modules sqlite3_api->drop_modules
/* Version 3.31.0 and later */
#define sqlite3_hard_heap_limit64 sqlite3_api->hard_heap_limit64
#define sqlite3_uri_key sqlite3_api->uri_key
#define sqlite3_filename_database sqlite3_api->filename_database
#define sqlite3_filename_journal sqlite3_api->filename_journal
#define sqlite3_filename_wal sqlite3_api->filename_wal
/* Version 3.32.0 and later */
#define sqlite3_create_filename sqlite3_api->create_filename
#define sqlite3_free_filename sqlite3_api->free_filename
#define sqlite3_database_file_object sqlite3_api->database_file_object
/* Version 3.34.0 and later */
#define sqlite3_txn_state sqlite3_api->txn_state
#endif /* !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION) */
#if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
/* This case when the file really is being compiled as a loadable
** extension */
# define SQLITE_EXTENSION_INIT1 const sqlite3_api_routines *sqlite3_api=0;
# define SQLITE_EXTENSION_INIT2(v) sqlite3_api=v;
# define SQLITE_EXTENSION_INIT3 \
extern const sqlite3_api_routines *sqlite3_api;
#else
/* This case when the file is being statically linked into the
** application */
# define SQLITE_EXTENSION_INIT1 /*no-op*/
# define SQLITE_EXTENSION_INIT2(v) (void)v; /* unused parameter */
# define SQLITE_EXTENSION_INIT3 /*no-op*/
#endif
#endif /* SQLITE3EXT_H */
/************** End of sqlite3ext.h ******************************************/
/************** Continuing where we left off in loadext.c ********************/
/* #include "sqliteInt.h" */
#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*
** Some API routines are omitted when various features are
** excluded from a build of SQLite. Substitute a NULL pointer
** for any missing APIs.
*/
#ifndef SQLITE_ENABLE_COLUMN_METADATA
# define sqlite3_column_database_name 0
# define sqlite3_column_database_name16 0
# define sqlite3_column_table_name 0
# define sqlite3_column_table_name16 0
# define sqlite3_column_origin_name 0
# define sqlite3_column_origin_name16 0
#endif
#ifdef SQLITE_OMIT_AUTHORIZATION
# define sqlite3_set_authorizer 0
#endif
#ifdef SQLITE_OMIT_UTF16
# define sqlite3_bind_text16 0
# define sqlite3_collation_needed16 0
# define sqlite3_column_decltype16 0
# define sqlite3_column_name16 0
# define sqlite3_column_text16 0
# define sqlite3_complete16 0
# define sqlite3_create_collation16 0
# define sqlite3_create_function16 0
# define sqlite3_errmsg16 0
# define sqlite3_open16 0
# define sqlite3_prepare16 0
# define sqlite3_prepare16_v2 0
# define sqlite3_prepare16_v3 0
# define sqlite3_result_error16 0
# define sqlite3_result_text16 0
# define sqlite3_result_text16be 0
# define sqlite3_result_text16le 0
# define sqlite3_value_text16 0
# define sqlite3_value_text16be 0
# define sqlite3_value_text16le 0
# define sqlite3_column_database_name16 0
# define sqlite3_column_table_name16 0
# define sqlite3_column_origin_name16 0
#endif
#ifdef SQLITE_OMIT_COMPLETE
# define sqlite3_complete 0
# define sqlite3_complete16 0
#endif
#ifdef SQLITE_OMIT_DECLTYPE
# define sqlite3_column_decltype16 0
# define sqlite3_column_decltype 0
#endif
#ifdef SQLITE_OMIT_PROGRESS_CALLBACK
# define sqlite3_progress_handler 0
#endif
#ifdef SQLITE_OMIT_VIRTUALTABLE
# define sqlite3_create_module 0
# define sqlite3_create_module_v2 0
# define sqlite3_declare_vtab 0
# define sqlite3_vtab_config 0
# define sqlite3_vtab_on_conflict 0
# define sqlite3_vtab_collation 0
#endif
#ifdef SQLITE_OMIT_SHARED_CACHE
# define sqlite3_enable_shared_cache 0
#endif
#if defined(SQLITE_OMIT_TRACE) || defined(SQLITE_OMIT_DEPRECATED)
# define sqlite3_profile 0
# define sqlite3_trace 0
#endif
#ifdef SQLITE_OMIT_GET_TABLE
# define sqlite3_free_table 0
# define sqlite3_get_table 0
#endif
#ifdef SQLITE_OMIT_INCRBLOB
#define sqlite3_bind_zeroblob 0
#define sqlite3_blob_bytes 0
#define sqlite3_blob_close 0
#define sqlite3_blob_open 0
#define sqlite3_blob_read 0
#define sqlite3_blob_write 0
#define sqlite3_blob_reopen 0
#endif
#if defined(SQLITE_OMIT_TRACE)
# define sqlite3_trace_v2 0
#endif
/*
** The following structure contains pointers to all SQLite API routines.
** A pointer to this structure is passed into extensions when they are
** loaded so that the extension can make calls back into the SQLite
** library.
**
** When adding new APIs, add them to the bottom of this structure
** in order to preserve backwards compatibility.
**
** Extensions that use newer APIs should first call the
** sqlite3_libversion_number() to make sure that the API they
** intend to use is supported by the library. Extensions should
** also check to make sure that the pointer to the function is
** not NULL before calling it.
*/
static const sqlite3_api_routines sqlite3Apis = {
sqlite3_aggregate_context,
#ifndef SQLITE_OMIT_DEPRECATED
sqlite3_aggregate_count,
#else
0,
#endif
sqlite3_bind_blob,
sqlite3_bind_double,
sqlite3_bind_int,
sqlite3_bind_int64,
sqlite3_bind_null,
sqlite3_bind_parameter_count,
sqlite3_bind_parameter_index,
sqlite3_bind_parameter_name,
sqlite3_bind_text,
sqlite3_bind_text16,
sqlite3_bind_value,
sqlite3_busy_handler,
sqlite3_busy_timeout,
sqlite3_changes,
sqlite3_close,
sqlite3_collation_needed,
sqlite3_collation_needed16,
sqlite3_column_blob,
sqlite3_column_bytes,
sqlite3_column_bytes16,
sqlite3_column_count,
sqlite3_column_database_name,
sqlite3_column_database_name16,
sqlite3_column_decltype,
sqlite3_column_decltype16,
sqlite3_column_double,
sqlite3_column_int,
sqlite3_column_int64,
sqlite3_column_name,
sqlite3_column_name16,
sqlite3_column_origin_name,
sqlite3_column_origin_name16,
sqlite3_column_table_name,
sqlite3_column_table_name16,
sqlite3_column_text,
sqlite3_column_text16,
sqlite3_column_type,
sqlite3_column_value,
sqlite3_commit_hook,
sqlite3_complete,
sqlite3_complete16,
sqlite3_create_collation,
sqlite3_create_collation16,
sqlite3_create_function,
sqlite3_create_function16,
sqlite3_create_module,
sqlite3_data_count,
sqlite3_db_handle,
sqlite3_declare_vtab,
sqlite3_enable_shared_cache,
sqlite3_errcode,
sqlite3_errmsg,
sqlite3_errmsg16,
sqlite3_exec,
#ifndef SQLITE_OMIT_DEPRECATED
sqlite3_expired,
#else
0,
#endif
sqlite3_finalize,
sqlite3_free,
sqlite3_free_table,
sqlite3_get_autocommit,
sqlite3_get_auxdata,
sqlite3_get_table,
0, /* Was sqlite3_global_recover(), but that function is deprecated */
sqlite3_interrupt,
sqlite3_last_insert_rowid,
sqlite3_libversion,
sqlite3_libversion_number,
sqlite3_malloc,
sqlite3_mprintf,
sqlite3_open,
sqlite3_open16,
sqlite3_prepare,
sqlite3_prepare16,
sqlite3_profile,
sqlite3_progress_handler,
sqlite3_realloc,
sqlite3_reset,
sqlite3_result_blob,
sqlite3_result_double,
sqlite3_result_error,
sqlite3_result_error16,
sqlite3_result_int,
sqlite3_result_int64,
sqlite3_result_null,
sqlite3_result_text,
sqlite3_result_text16,
sqlite3_result_text16be,
sqlite3_result_text16le,
sqlite3_result_value,
sqlite3_rollback_hook,
sqlite3_set_authorizer,
sqlite3_set_auxdata,
sqlite3_snprintf,
sqlite3_step,
sqlite3_table_column_metadata,
#ifndef SQLITE_OMIT_DEPRECATED
sqlite3_thread_cleanup,
#else
0,
#endif
sqlite3_total_changes,
sqlite3_trace,
#ifndef SQLITE_OMIT_DEPRECATED
sqlite3_transfer_bindings,
#else
0,
#endif
sqlite3_update_hook,
sqlite3_user_data,
sqlite3_value_blob,
sqlite3_value_bytes,
sqlite3_value_bytes16,
sqlite3_value_double,
sqlite3_value_int,
sqlite3_value_int64,
sqlite3_value_numeric_type,
sqlite3_value_text,
sqlite3_value_text16,
sqlite3_value_text16be,
sqlite3_value_text16le,
sqlite3_value_type,
sqlite3_vmprintf,
/*
** The original API set ends here. All extensions can call any
** of the APIs above provided that the pointer is not NULL. But
** before calling APIs that follow, extension should check the
** sqlite3_libversion_number() to make sure they are dealing with
** a library that is new enough to support that API.
*************************************************************************
*/
sqlite3_overload_function,
/*
** Added after 3.3.13
*/
sqlite3_prepare_v2,
sqlite3_prepare16_v2,
sqlite3_clear_bindings,
/*
** Added for 3.4.1
*/
sqlite3_create_module_v2,
/*
** Added for 3.5.0
*/
sqlite3_bind_zeroblob,
sqlite3_blob_bytes,
sqlite3_blob_close,
sqlite3_blob_open,
sqlite3_blob_read,
sqlite3_blob_write,
sqlite3_create_collation_v2,
sqlite3_file_control,
sqlite3_memory_highwater,
sqlite3_memory_used,
#ifdef SQLITE_MUTEX_OMIT
0,
0,
0,
0,
0,
#else
sqlite3_mutex_alloc,
sqlite3_mutex_enter,
sqlite3_mutex_free,
sqlite3_mutex_leave,
sqlite3_mutex_try,
#endif
sqlite3_open_v2,
sqlite3_release_memory,
sqlite3_result_error_nomem,
sqlite3_result_error_toobig,
sqlite3_sleep,
sqlite3_soft_heap_limit,
sqlite3_vfs_find,
sqlite3_vfs_register,
sqlite3_vfs_unregister,
/*
** Added for 3.5.8
*/
sqlite3_threadsafe,
sqlite3_result_zeroblob,
sqlite3_result_error_code,
sqlite3_test_control,
sqlite3_randomness,
sqlite3_context_db_handle,
/*
** Added for 3.6.0
*/
sqlite3_extended_result_codes,
sqlite3_limit,
sqlite3_next_stmt,
sqlite3_sql,
sqlite3_status,
/*
** Added for 3.7.4
*/
sqlite3_backup_finish,
sqlite3_backup_init,
sqlite3_backup_pagecount,
sqlite3_backup_remaining,
sqlite3_backup_step,
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
sqlite3_compileoption_get,
sqlite3_compileoption_used,
#else
0,
0,
#endif
sqlite3_create_function_v2,
sqlite3_db_config,
sqlite3_db_mutex,
sqlite3_db_status,
sqlite3_extended_errcode,
sqlite3_log,
sqlite3_soft_heap_limit64,
sqlite3_sourceid,
sqlite3_stmt_status,
sqlite3_strnicmp,
#ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
sqlite3_unlock_notify,
#else
0,
#endif
#ifndef SQLITE_OMIT_WAL
sqlite3_wal_autocheckpoint,
sqlite3_wal_checkpoint,
sqlite3_wal_hook,
#else
0,
0,
0,
#endif
sqlite3_blob_reopen,
sqlite3_vtab_config,
sqlite3_vtab_on_conflict,
sqlite3_close_v2,
sqlite3_db_filename,
sqlite3_db_readonly,
sqlite3_db_release_memory,
sqlite3_errstr,
sqlite3_stmt_busy,
sqlite3_stmt_readonly,
sqlite3_stricmp,
sqlite3_uri_boolean,
sqlite3_uri_int64,
sqlite3_uri_parameter,
sqlite3_vsnprintf,
sqlite3_wal_checkpoint_v2,
/* Version 3.8.7 and later */
sqlite3_auto_extension,
sqlite3_bind_blob64,
sqlite3_bind_text64,
sqlite3_cancel_auto_extension,
sqlite3_load_extension,
sqlite3_malloc64,
sqlite3_msize,
sqlite3_realloc64,
sqlite3_reset_auto_extension,
sqlite3_result_blob64,
sqlite3_result_text64,
sqlite3_strglob,
/* Version 3.8.11 and later */
(sqlite3_value*(*)(const sqlite3_value*))sqlite3_value_dup,
sqlite3_value_free,
sqlite3_result_zeroblob64,
sqlite3_bind_zeroblob64,
/* Version 3.9.0 and later */
sqlite3_value_subtype,
sqlite3_result_subtype,
/* Version 3.10.0 and later */
sqlite3_status64,
sqlite3_strlike,
sqlite3_db_cacheflush,
/* Version 3.12.0 and later */
sqlite3_system_errno,
/* Version 3.14.0 and later */
sqlite3_trace_v2,
sqlite3_expanded_sql,
/* Version 3.18.0 and later */
sqlite3_set_last_insert_rowid,
/* Version 3.20.0 and later */
sqlite3_prepare_v3,
sqlite3_prepare16_v3,
sqlite3_bind_pointer,
sqlite3_result_pointer,
sqlite3_value_pointer,
/* Version 3.22.0 and later */
sqlite3_vtab_nochange,
sqlite3_value_nochange,
sqlite3_vtab_collation,
/* Version 3.24.0 and later */
sqlite3_keyword_count,
sqlite3_keyword_name,
sqlite3_keyword_check,
sqlite3_str_new,
sqlite3_str_finish,
sqlite3_str_appendf,
sqlite3_str_vappendf,
sqlite3_str_append,
sqlite3_str_appendall,
sqlite3_str_appendchar,
sqlite3_str_reset,
sqlite3_str_errcode,
sqlite3_str_length,
sqlite3_str_value,
/* Version 3.25.0 and later */
sqlite3_create_window_function,
/* Version 3.26.0 and later */
#ifdef SQLITE_ENABLE_NORMALIZE
sqlite3_normalized_sql,
#else
0,
#endif
/* Version 3.28.0 and later */
sqlite3_stmt_isexplain,
sqlite3_value_frombind,
/* Version 3.30.0 and later */
#ifndef SQLITE_OMIT_VIRTUALTABLE
sqlite3_drop_modules,
#else
0,
#endif
/* Version 3.31.0 and later */
sqlite3_hard_heap_limit64,
sqlite3_uri_key,
sqlite3_filename_database,
sqlite3_filename_journal,
sqlite3_filename_wal,
/* Version 3.32.0 and later */
sqlite3_create_filename,
sqlite3_free_filename,
sqlite3_database_file_object,
/* Version 3.34.0 and later */
sqlite3_txn_state,
};
/* True if x is the directory separator character
*/
#if SQLITE_OS_WIN
# define DirSep(X) ((X)=='/'||(X)=='\\')
#else
# define DirSep(X) ((X)=='/')
#endif
/*
** Attempt to load an SQLite extension library contained in the file
** zFile. The entry point is zProc. zProc may be 0 in which case a
** default entry point name (sqlite3_extension_init) is used. Use
** of the default name is recommended.
**
** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
**
** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
** error message text. The calling function should free this memory
** by calling sqlite3DbFree(db, ).
*/
static int sqlite3LoadExtension(
sqlite3 *db, /* Load the extension into this database connection */
const char *zFile, /* Name of the shared library containing extension */
const char *zProc, /* Entry point. Use "sqlite3_extension_init" if 0 */
char **pzErrMsg /* Put error message here if not 0 */
){
sqlite3_vfs *pVfs = db->pVfs;
void *handle;
sqlite3_loadext_entry xInit;
char *zErrmsg = 0;
const char *zEntry;
char *zAltEntry = 0;
void **aHandle;
u64 nMsg = 300 + sqlite3Strlen30(zFile);
int ii;
int rc;
/* Shared library endings to try if zFile cannot be loaded as written */
static const char *azEndings[] = {
#if SQLITE_OS_WIN
"dll"
#elif defined(__APPLE__)
"dylib"
#else
"so"
#endif
};
if( pzErrMsg ) *pzErrMsg = 0;
/* Ticket #1863. To avoid a creating security problems for older
** applications that relink against newer versions of SQLite, the
** ability to run load_extension is turned off by default. One
** must call either sqlite3_enable_load_extension(db) or
** sqlite3_db_config(db, SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, 1, 0)
** to turn on extension loading.
*/
if( (db->flags & SQLITE_LoadExtension)==0 ){
if( pzErrMsg ){
*pzErrMsg = sqlite3_mprintf("not authorized");
}
return SQLITE_ERROR;
}
zEntry = zProc ? zProc : "sqlite3_extension_init";
handle = sqlite3OsDlOpen(pVfs, zFile);
#if SQLITE_OS_UNIX || SQLITE_OS_WIN
for(ii=0; ii<ArraySize(azEndings) && handle==0; ii++){
char *zAltFile = sqlite3_mprintf("%s.%s", zFile, azEndings[ii]);
if( zAltFile==0 ) return SQLITE_NOMEM_BKPT;
handle = sqlite3OsDlOpen(pVfs, zAltFile);
sqlite3_free(zAltFile);
}
#endif
if( handle==0 ){
if( pzErrMsg ){
*pzErrMsg = zErrmsg = sqlite3_malloc64(nMsg);
if( zErrmsg ){
sqlite3_snprintf(nMsg, zErrmsg,
"unable to open shared library [%s]", zFile);
sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
}
}
return SQLITE_ERROR;
}
xInit = (sqlite3_loadext_entry)sqlite3OsDlSym(pVfs, handle, zEntry);
/* If no entry point was specified and the default legacy
** entry point name "sqlite3_extension_init" was not found, then
** construct an entry point name "sqlite3_X_init" where the X is
** replaced by the lowercase value of every ASCII alphabetic
** character in the filename after the last "/" upto the first ".",
** and eliding the first three characters if they are "lib".
** Examples:
**
** /usr/local/lib/libExample5.4.3.so ==> sqlite3_example_init
** C:/lib/mathfuncs.dll ==> sqlite3_mathfuncs_init
*/
if( xInit==0 && zProc==0 ){
int iFile, iEntry, c;
int ncFile = sqlite3Strlen30(zFile);
zAltEntry = sqlite3_malloc64(ncFile+30);
if( zAltEntry==0 ){
sqlite3OsDlClose(pVfs, handle);
return SQLITE_NOMEM_BKPT;
}
memcpy(zAltEntry, "sqlite3_", 8);
for(iFile=ncFile-1; iFile>=0 && !DirSep(zFile[iFile]); iFile--){}
iFile++;
if( sqlite3_strnicmp(zFile+iFile, "lib", 3)==0 ) iFile += 3;
for(iEntry=8; (c = zFile[iFile])!=0 && c!='.'; iFile++){
if( sqlite3Isalpha(c) ){
zAltEntry[iEntry++] = (char)sqlite3UpperToLower[(unsigned)c];
}
}
memcpy(zAltEntry+iEntry, "_init", 6);
zEntry = zAltEntry;
xInit = (sqlite3_loadext_entry)sqlite3OsDlSym(pVfs, handle, zEntry);
}
if( xInit==0 ){
if( pzErrMsg ){
nMsg += sqlite3Strlen30(zEntry);
*pzErrMsg = zErrmsg = sqlite3_malloc64(nMsg);
if( zErrmsg ){
sqlite3_snprintf(nMsg, zErrmsg,
"no entry point [%s] in shared library [%s]", zEntry, zFile);
sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
}
}
sqlite3OsDlClose(pVfs, handle);
sqlite3_free(zAltEntry);
return SQLITE_ERROR;
}
sqlite3_free(zAltEntry);
rc = xInit(db, &zErrmsg, &sqlite3Apis);
if( rc ){
if( rc==SQLITE_OK_LOAD_PERMANENTLY ) return SQLITE_OK;
if( pzErrMsg ){
*pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
}
sqlite3_free(zErrmsg);
sqlite3OsDlClose(pVfs, handle);
return SQLITE_ERROR;
}
/* Append the new shared library handle to the db->aExtension array. */
aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1));
if( aHandle==0 ){
return SQLITE_NOMEM_BKPT;
}
if( db->nExtension>0 ){
memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension);
}
sqlite3DbFree(db, db->aExtension);
db->aExtension = aHandle;
db->aExtension[db->nExtension++] = handle;
return SQLITE_OK;
}
SQLITE_API int SQLITE_APICALL sqlite3_load_extension(
sqlite3 *db, /* Load the extension into this database connection */
const char *zFile, /* Name of the shared library containing extension */
const char *zProc, /* Entry point. Use "sqlite3_extension_init" if 0 */
char **pzErrMsg /* Put error message here if not 0 */
){
int rc;
sqlite3_mutex_enter(db->mutex);
rc = sqlite3LoadExtension(db, zFile, zProc, pzErrMsg);
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** Call this routine when the database connection is closing in order
** to clean up loaded extensions
*/
SQLITE_PRIVATE void sqlite3CloseExtensions(sqlite3 *db){
int i;
assert( sqlite3_mutex_held(db->mutex) );
for(i=0; i<db->nExtension; i++){
sqlite3OsDlClose(db->pVfs, db->aExtension[i]);
}
sqlite3DbFree(db, db->aExtension);
}
/*
** Enable or disable extension loading. Extension loading is disabled by
** default so as not to open security holes in older applications.
*/
SQLITE_API int SQLITE_APICALL sqlite3_enable_load_extension(sqlite3 *db, int onoff){
sqlite3_mutex_enter(db->mutex);
if( onoff ){
db->flags |= SQLITE_LoadExtension|SQLITE_LoadExtFunc;
}else{
db->flags &= ~(u64)(SQLITE_LoadExtension|SQLITE_LoadExtFunc);
}
sqlite3_mutex_leave(db->mutex);
return SQLITE_OK;
}
#endif /* !defined(SQLITE_OMIT_LOAD_EXTENSION) */
/*
** The following object holds the list of automatically loaded
** extensions.
**
** This list is shared across threads. The SQLITE_MUTEX_STATIC_MAIN
** mutex must be held while accessing this list.
*/
typedef struct sqlite3AutoExtList sqlite3AutoExtList;
static SQLITE_WSD struct sqlite3AutoExtList {
u32 nExt; /* Number of entries in aExt[] */
void (**aExt)(void); /* Pointers to the extension init functions */
} sqlite3Autoext = { 0, 0 };
/* The "wsdAutoext" macro will resolve to the autoextension
** state vector. If writable static data is unsupported on the target,
** we have to locate the state vector at run-time. In the more common
** case where writable static data is supported, wsdStat can refer directly
** to the "sqlite3Autoext" state vector declared above.
*/
#ifdef SQLITE_OMIT_WSD
# define wsdAutoextInit \
sqlite3AutoExtList *x = &GLOBAL(sqlite3AutoExtList,sqlite3Autoext)
# define wsdAutoext x[0]
#else
# define wsdAutoextInit
# define wsdAutoext sqlite3Autoext
#endif
/*
** Register a statically linked extension that is automatically
** loaded by every new database connection.
*/
SQLITE_API int SQLITE_APICALL sqlite3_auto_extension(
void (*xInit)(void)
){
int rc = SQLITE_OK;
#ifndef SQLITE_OMIT_AUTOINIT
rc = sqlite3_initialize();
if( rc ){
return rc;
}else
#endif
{
u32 i;
#if SQLITE_THREADSAFE
sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
wsdAutoextInit;
sqlite3_mutex_enter(mutex);
for(i=0; i<wsdAutoext.nExt; i++){
if( wsdAutoext.aExt[i]==xInit ) break;
}
if( i==wsdAutoext.nExt ){
u64 nByte = (wsdAutoext.nExt+1)*sizeof(wsdAutoext.aExt[0]);
void (**aNew)(void);
aNew = sqlite3_realloc64(wsdAutoext.aExt, nByte);
if( aNew==0 ){
rc = SQLITE_NOMEM_BKPT;
}else{
wsdAutoext.aExt = aNew;
wsdAutoext.aExt[wsdAutoext.nExt] = xInit;
wsdAutoext.nExt++;
}
}
sqlite3_mutex_leave(mutex);
assert( (rc&0xff)==rc );
return rc;
}
}
/*
** Cancel a prior call to sqlite3_auto_extension. Remove xInit from the
** set of routines that is invoked for each new database connection, if it
** is currently on the list. If xInit is not on the list, then this
** routine is a no-op.
**
** Return 1 if xInit was found on the list and removed. Return 0 if xInit
** was not on the list.
*/
SQLITE_API int SQLITE_APICALL sqlite3_cancel_auto_extension(
void (*xInit)(void)
){
#if SQLITE_THREADSAFE
sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
int i;
int n = 0;
wsdAutoextInit;
sqlite3_mutex_enter(mutex);
for(i=(int)wsdAutoext.nExt-1; i>=0; i--){
if( wsdAutoext.aExt[i]==xInit ){
wsdAutoext.nExt--;
wsdAutoext.aExt[i] = wsdAutoext.aExt[wsdAutoext.nExt];
n++;
break;
}
}
sqlite3_mutex_leave(mutex);
return n;
}
/*
** Reset the automatic extension loading mechanism.
*/
SQLITE_API void SQLITE_APICALL sqlite3_reset_auto_extension(void){
#ifndef SQLITE_OMIT_AUTOINIT
if( sqlite3_initialize()==SQLITE_OK )
#endif
{
#if SQLITE_THREADSAFE
sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
wsdAutoextInit;
sqlite3_mutex_enter(mutex);
sqlite3_free(wsdAutoext.aExt);
wsdAutoext.aExt = 0;
wsdAutoext.nExt = 0;
sqlite3_mutex_leave(mutex);
}
}
/*
** Load all automatic extensions.
**
** If anything goes wrong, set an error in the database connection.
*/
SQLITE_PRIVATE void sqlite3AutoLoadExtensions(sqlite3 *db){
u32 i;
int go = 1;
int rc;
sqlite3_loadext_entry xInit;
wsdAutoextInit;
if( wsdAutoext.nExt==0 ){
/* Common case: early out without every having to acquire a mutex */
return;
}
for(i=0; go; i++){
char *zErrmsg;
#if SQLITE_THREADSAFE
sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN);
#endif
#ifdef SQLITE_OMIT_LOAD_EXTENSION
const sqlite3_api_routines *pThunk = 0;
#else
const sqlite3_api_routines *pThunk = &sqlite3Apis;
#endif
sqlite3_mutex_enter(mutex);
if( i>=wsdAutoext.nExt ){
xInit = 0;
go = 0;
}else{
xInit = (sqlite3_loadext_entry)wsdAutoext.aExt[i];
}
sqlite3_mutex_leave(mutex);
zErrmsg = 0;
if( xInit && (rc = xInit(db, &zErrmsg, pThunk))!=0 ){
sqlite3ErrorWithMsg(db, rc,
"automatic extension loading failed: %s", zErrmsg);
go = 0;
}
sqlite3_free(zErrmsg);
}
}
/************** End of loadext.c *********************************************/
/************** Begin file pragma.c ******************************************/
/*
** 2003 April 6
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
*/
/* #include "sqliteInt.h" */
#if !defined(SQLITE_ENABLE_LOCKING_STYLE)
# if defined(__APPLE__)
# define SQLITE_ENABLE_LOCKING_STYLE 1
# else
# define SQLITE_ENABLE_LOCKING_STYLE 0
# endif
#endif
/***************************************************************************
** The "pragma.h" include file is an automatically generated file that
** that includes the PragType_XXXX macro definitions and the aPragmaName[]
** object. This ensures that the aPragmaName[] table is arranged in
** lexicographical order to facility a binary search of the pragma name.
** Do not edit pragma.h directly. Edit and rerun the script in at
** ../tool/mkpragmatab.tcl. */
/************** Include pragma.h in the middle of pragma.c *******************/
/************** Begin file pragma.h ******************************************/
/* DO NOT EDIT!
** This file is automatically generated by the script at
** ../tool/mkpragmatab.tcl. To update the set of pragmas, edit
** that script and rerun it.
*/
/* The various pragma types */
#define PragTyp_ACTIVATE_EXTENSIONS 0
#define PragTyp_ANALYSIS_LIMIT 1
#define PragTyp_HEADER_VALUE 2
#define PragTyp_AUTO_VACUUM 3
#define PragTyp_FLAG 4
#define PragTyp_BUSY_TIMEOUT 5
#define PragTyp_CACHE_SIZE 6
#define PragTyp_CACHE_SPILL 7
#define PragTyp_CASE_SENSITIVE_LIKE 8
#define PragTyp_COLLATION_LIST 9
#define PragTyp_COMPILE_OPTIONS 10
#define PragTyp_DATA_STORE_DIRECTORY 11
#define PragTyp_DATABASE_LIST 12
#define PragTyp_DEFAULT_CACHE_SIZE 13
#define PragTyp_ENCODING 14
#define PragTyp_FOREIGN_KEY_CHECK 15
#define PragTyp_FOREIGN_KEY_LIST 16
#define PragTyp_FUNCTION_LIST 17
#define PragTyp_HARD_HEAP_LIMIT 18
#define PragTyp_INCREMENTAL_VACUUM 19
#define PragTyp_INDEX_INFO 20
#define PragTyp_INDEX_LIST 21
#define PragTyp_INTEGRITY_CHECK 22
#define PragTyp_JOURNAL_MODE 23
#define PragTyp_JOURNAL_SIZE_LIMIT 24
#define PragTyp_LOCK_PROXY_FILE 25
#define PragTyp_LOCKING_MODE 26
#define PragTyp_PAGE_COUNT 27
#define PragTyp_MMAP_SIZE 28
#define PragTyp_MODULE_LIST 29
#define PragTyp_OPTIMIZE 30
#define PragTyp_PAGE_SIZE 31
#define PragTyp_PRAGMA_LIST 32
#define PragTyp_SECURE_DELETE 33
#define PragTyp_SHRINK_MEMORY 34
#define PragTyp_SOFT_HEAP_LIMIT 35
#define PragTyp_SYNCHRONOUS 36
#define PragTyp_TABLE_INFO 37
#define PragTyp_TEMP_STORE 38
#define PragTyp_TEMP_STORE_DIRECTORY 39
#define PragTyp_THREADS 40
#define PragTyp_WAL_AUTOCHECKPOINT 41
#define PragTyp_WAL_CHECKPOINT 42
#define PragTyp_LOCK_STATUS 43
#define PragTyp_STATS 44
/* Property flags associated with various pragma. */
#define PragFlg_NeedSchema 0x01 /* Force schema load before running */
#define PragFlg_NoColumns 0x02 /* OP_ResultRow called with zero columns */
#define PragFlg_NoColumns1 0x04 /* zero columns if RHS argument is present */
#define PragFlg_ReadOnly 0x08 /* Read-only HEADER_VALUE */
#define PragFlg_Result0 0x10 /* Acts as query when no argument */
#define PragFlg_Result1 0x20 /* Acts as query when has one argument */
#define PragFlg_SchemaOpt 0x40 /* Schema restricts name search if present */
#define PragFlg_SchemaReq 0x80 /* Schema required - "main" is default */
/* Names of columns for pragmas that return multi-column result
** or that return single-column results where the name of the
** result column is different from the name of the pragma
*/
static const char *const pragCName[] = {
/* 0 */ "id", /* Used by: foreign_key_list */
/* 1 */ "seq",
/* 2 */ "table",
/* 3 */ "from",
/* 4 */ "to",
/* 5 */ "on_update",
/* 6 */ "on_delete",
/* 7 */ "match",
/* 8 */ "cid", /* Used by: table_xinfo */
/* 9 */ "name",
/* 10 */ "type",
/* 11 */ "notnull",
/* 12 */ "dflt_value",
/* 13 */ "pk",
/* 14 */ "hidden",
/* table_info reuses 8 */
/* 15 */ "seqno", /* Used by: index_xinfo */
/* 16 */ "cid",
/* 17 */ "name",
/* 18 */ "desc",
/* 19 */ "coll",
/* 20 */ "key",
/* 21 */ "name", /* Used by: function_list */
/* 22 */ "builtin",
/* 23 */ "type",
/* 24 */ "enc",
/* 25 */ "narg",
/* 26 */ "flags",
/* 27 */ "tbl", /* Used by: stats */
/* 28 */ "idx",
/* 29 */ "wdth",
/* 30 */ "hght",
/* 31 */ "flgs",
/* 32 */ "seq", /* Used by: index_list */
/* 33 */ "name",
/* 34 */ "unique",
/* 35 */ "origin",
/* 36 */ "partial",
/* 37 */ "table", /* Used by: foreign_key_check */
/* 38 */ "rowid",
/* 39 */ "parent",
/* 40 */ "fkid",
/* index_info reuses 15 */
/* 41 */ "seq", /* Used by: database_list */
/* 42 */ "name",
/* 43 */ "file",
/* 44 */ "busy", /* Used by: wal_checkpoint */
/* 45 */ "log",
/* 46 */ "checkpointed",
/* collation_list reuses 32 */
/* 47 */ "database", /* Used by: lock_status */
/* 48 */ "status",
/* 49 */ "cache_size", /* Used by: default_cache_size */
/* module_list pragma_list reuses 9 */
/* 50 */ "timeout", /* Used by: busy_timeout */
};
/* Definitions of all built-in pragmas */
typedef struct PragmaName {
const char *const zName; /* Name of pragma */
u8 ePragTyp; /* PragTyp_XXX value */
u8 mPragFlg; /* Zero or more PragFlg_XXX values */
u8 iPragCName; /* Start of column names in pragCName[] */
u8 nPragCName; /* Num of col names. 0 means use pragma name */
u64 iArg; /* Extra argument */
} PragmaName;
static const PragmaName aPragmaName[] = {
#if defined(SQLITE_ENABLE_CEROD)
{/* zName: */ "activate_extensions",
/* ePragTyp: */ PragTyp_ACTIVATE_EXTENSIONS,
/* ePragFlg: */ 0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
{/* zName: */ "analysis_limit",
/* ePragTyp: */ PragTyp_ANALYSIS_LIMIT,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
{/* zName: */ "application_id",
/* ePragTyp: */ PragTyp_HEADER_VALUE,
/* ePragFlg: */ PragFlg_NoColumns1|PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ BTREE_APPLICATION_ID },
#endif
#if !defined(SQLITE_OMIT_AUTOVACUUM)
{/* zName: */ "auto_vacuum",
/* ePragTyp: */ PragTyp_AUTO_VACUUM,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
#if !defined(SQLITE_OMIT_AUTOMATIC_INDEX)
{/* zName: */ "automatic_index",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_AutoIndex },
#endif
#endif
{/* zName: */ "busy_timeout",
/* ePragTyp: */ PragTyp_BUSY_TIMEOUT,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 50, 1,
/* iArg: */ 0 },
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
{/* zName: */ "cache_size",
/* ePragTyp: */ PragTyp_CACHE_SIZE,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "cache_spill",
/* ePragTyp: */ PragTyp_CACHE_SPILL,
/* ePragFlg: */ PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_CASE_SENSITIVE_LIKE_PRAGMA)
{/* zName: */ "case_sensitive_like",
/* ePragTyp: */ PragTyp_CASE_SENSITIVE_LIKE,
/* ePragFlg: */ PragFlg_NoColumns,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
{/* zName: */ "cell_size_check",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_CellSizeCk },
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "checkpoint_fullfsync",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_CkptFullFSync },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
{/* zName: */ "collation_list",
/* ePragTyp: */ PragTyp_COLLATION_LIST,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 32, 2,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_COMPILEOPTION_DIAGS)
{/* zName: */ "compile_options",
/* ePragTyp: */ PragTyp_COMPILE_OPTIONS,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "count_changes",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_CountRows },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_OS_WIN
{/* zName: */ "data_store_directory",
/* ePragTyp: */ PragTyp_DATA_STORE_DIRECTORY,
/* ePragFlg: */ PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
{/* zName: */ "data_version",
/* ePragTyp: */ PragTyp_HEADER_VALUE,
/* ePragFlg: */ PragFlg_ReadOnly|PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ BTREE_DATA_VERSION },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
{/* zName: */ "database_list",
/* ePragTyp: */ PragTyp_DATABASE_LIST,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0,
/* ColNames: */ 41, 3,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
{/* zName: */ "default_cache_size",
/* ePragTyp: */ PragTyp_DEFAULT_CACHE_SIZE,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
/* ColNames: */ 49, 1,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
{/* zName: */ "defer_foreign_keys",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_DeferFKs },
#endif
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "empty_result_callbacks",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_NullCallback },
#endif
#if !defined(SQLITE_OMIT_UTF16)
{/* zName: */ "encoding",
/* ePragTyp: */ PragTyp_ENCODING,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
{/* zName: */ "foreign_key_check",
/* ePragTyp: */ PragTyp_FOREIGN_KEY_CHECK,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_Result1|PragFlg_SchemaOpt,
/* ColNames: */ 37, 4,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FOREIGN_KEY)
{/* zName: */ "foreign_key_list",
/* ePragTyp: */ PragTyp_FOREIGN_KEY_LIST,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
/* ColNames: */ 0, 8,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
#if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
{/* zName: */ "foreign_keys",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_ForeignKeys },
#endif
#endif
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
{/* zName: */ "freelist_count",
/* ePragTyp: */ PragTyp_HEADER_VALUE,
/* ePragFlg: */ PragFlg_ReadOnly|PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ BTREE_FREE_PAGE_COUNT },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "full_column_names",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_FullColNames },
{/* zName: */ "fullfsync",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_FullFSync },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
#if !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
{/* zName: */ "function_list",
/* ePragTyp: */ PragTyp_FUNCTION_LIST,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 21, 6,
/* iArg: */ 0 },
#endif
#endif
{/* zName: */ "hard_heap_limit",
/* ePragTyp: */ PragTyp_HARD_HEAP_LIMIT,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
#if !defined(SQLITE_OMIT_CHECK)
{/* zName: */ "ignore_check_constraints",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_IgnoreChecks },
#endif
#endif
#if !defined(SQLITE_OMIT_AUTOVACUUM)
{/* zName: */ "incremental_vacuum",
/* ePragTyp: */ PragTyp_INCREMENTAL_VACUUM,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_NoColumns,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
{/* zName: */ "index_info",
/* ePragTyp: */ PragTyp_INDEX_INFO,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
/* ColNames: */ 15, 3,
/* iArg: */ 0 },
{/* zName: */ "index_list",
/* ePragTyp: */ PragTyp_INDEX_LIST,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
/* ColNames: */ 32, 5,
/* iArg: */ 0 },
{/* zName: */ "index_xinfo",
/* ePragTyp: */ PragTyp_INDEX_INFO,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
/* ColNames: */ 15, 6,
/* iArg: */ 1 },
#endif
#if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
{/* zName: */ "integrity_check",
/* ePragTyp: */ PragTyp_INTEGRITY_CHECK,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_Result1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
{/* zName: */ "journal_mode",
/* ePragTyp: */ PragTyp_JOURNAL_MODE,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
{/* zName: */ "journal_size_limit",
/* ePragTyp: */ PragTyp_JOURNAL_SIZE_LIMIT,
/* ePragFlg: */ PragFlg_Result0|PragFlg_SchemaReq,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "legacy_alter_table",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_LegacyAlter },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_ENABLE_LOCKING_STYLE
{/* zName: */ "lock_proxy_file",
/* ePragTyp: */ PragTyp_LOCK_PROXY_FILE,
/* ePragFlg: */ PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
{/* zName: */ "lock_status",
/* ePragTyp: */ PragTyp_LOCK_STATUS,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 47, 2,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
{/* zName: */ "locking_mode",
/* ePragTyp: */ PragTyp_LOCKING_MODE,
/* ePragFlg: */ PragFlg_Result0|PragFlg_SchemaReq,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
{/* zName: */ "max_page_count",
/* ePragTyp: */ PragTyp_PAGE_COUNT,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
{/* zName: */ "mmap_size",
/* ePragTyp: */ PragTyp_MMAP_SIZE,
/* ePragFlg: */ 0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
#if !defined(SQLITE_OMIT_VIRTUALTABLE)
#if !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
{/* zName: */ "module_list",
/* ePragTyp: */ PragTyp_MODULE_LIST,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 9, 1,
/* iArg: */ 0 },
#endif
#endif
#endif
{/* zName: */ "optimize",
/* ePragTyp: */ PragTyp_OPTIMIZE,
/* ePragFlg: */ PragFlg_Result1|PragFlg_NeedSchema,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
{/* zName: */ "page_count",
/* ePragTyp: */ PragTyp_PAGE_COUNT,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
{/* zName: */ "page_size",
/* ePragTyp: */ PragTyp_PAGE_SIZE,
/* ePragFlg: */ PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
#if defined(SQLITE_DEBUG)
{/* zName: */ "parser_trace",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_ParserTrace },
#endif
#endif
#if !defined(SQLITE_OMIT_INTROSPECTION_PRAGMAS)
{/* zName: */ "pragma_list",
/* ePragTyp: */ PragTyp_PRAGMA_LIST,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 9, 1,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "query_only",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_QueryOnly },
#endif
#if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
{/* zName: */ "quick_check",
/* ePragTyp: */ PragTyp_INTEGRITY_CHECK,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_Result1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "read_uncommitted",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_ReadUncommit },
{/* zName: */ "recursive_triggers",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_RecTriggers },
{/* zName: */ "reverse_unordered_selects",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_ReverseOrder },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
{/* zName: */ "schema_version",
/* ePragTyp: */ PragTyp_HEADER_VALUE,
/* ePragFlg: */ PragFlg_NoColumns1|PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ BTREE_SCHEMA_VERSION },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
{/* zName: */ "secure_delete",
/* ePragTyp: */ PragTyp_SECURE_DELETE,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "short_column_names",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_ShortColNames },
#endif
{/* zName: */ "shrink_memory",
/* ePragTyp: */ PragTyp_SHRINK_MEMORY,
/* ePragFlg: */ PragFlg_NoColumns,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
{/* zName: */ "soft_heap_limit",
/* ePragTyp: */ PragTyp_SOFT_HEAP_LIMIT,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
#if defined(SQLITE_DEBUG)
{/* zName: */ "sql_trace",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_SqlTrace },
#endif
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS) && defined(SQLITE_DEBUG)
{/* zName: */ "stats",
/* ePragTyp: */ PragTyp_STATS,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq,
/* ColNames: */ 27, 5,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
{/* zName: */ "synchronous",
/* ePragTyp: */ PragTyp_SYNCHRONOUS,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result0|PragFlg_SchemaReq|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
{/* zName: */ "table_info",
/* ePragTyp: */ PragTyp_TABLE_INFO,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
/* ColNames: */ 8, 6,
/* iArg: */ 0 },
{/* zName: */ "table_xinfo",
/* ePragTyp: */ PragTyp_TABLE_INFO,
/* ePragFlg: */ PragFlg_NeedSchema|PragFlg_Result1|PragFlg_SchemaOpt,
/* ColNames: */ 8, 7,
/* iArg: */ 1 },
#endif
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
{/* zName: */ "temp_store",
/* ePragTyp: */ PragTyp_TEMP_STORE,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
{/* zName: */ "temp_store_directory",
/* ePragTyp: */ PragTyp_TEMP_STORE_DIRECTORY,
/* ePragFlg: */ PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#endif
{/* zName: */ "threads",
/* ePragTyp: */ PragTyp_THREADS,
/* ePragFlg: */ PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "trusted_schema",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_TrustedSchema },
#endif
#if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
{/* zName: */ "user_version",
/* ePragTyp: */ PragTyp_HEADER_VALUE,
/* ePragFlg: */ PragFlg_NoColumns1|PragFlg_Result0,
/* ColNames: */ 0, 0,
/* iArg: */ BTREE_USER_VERSION },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
#if defined(SQLITE_DEBUG)
{/* zName: */ "vdbe_addoptrace",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_VdbeAddopTrace },
{/* zName: */ "vdbe_debug",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_SqlTrace|SQLITE_VdbeListing|SQLITE_VdbeTrace },
{/* zName: */ "vdbe_eqp",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_VdbeEQP },
{/* zName: */ "vdbe_listing",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_VdbeListing },
{/* zName: */ "vdbe_trace",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_VdbeTrace },
#endif
#endif
#if !defined(SQLITE_OMIT_WAL)
{/* zName: */ "wal_autocheckpoint",
/* ePragTyp: */ PragTyp_WAL_AUTOCHECKPOINT,
/* ePragFlg: */ 0,
/* ColNames: */ 0, 0,
/* iArg: */ 0 },
{/* zName: */ "wal_checkpoint",
/* ePragTyp: */ PragTyp_WAL_CHECKPOINT,
/* ePragFlg: */ PragFlg_NeedSchema,
/* ColNames: */ 44, 3,
/* iArg: */ 0 },
#endif
#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
{/* zName: */ "writable_schema",
/* ePragTyp: */ PragTyp_FLAG,
/* ePragFlg: */ PragFlg_Result0|PragFlg_NoColumns1,
/* ColNames: */ 0, 0,
/* iArg: */ SQLITE_WriteSchema|SQLITE_NoSchemaError },
#endif
};
/* Number of pragmas: 67 on by default, 77 total. */
/************** End of pragma.h **********************************************/
/************** Continuing where we left off in pragma.c *********************/
/*
** Interpret the given string as a safety level. Return 0 for OFF,
** 1 for ON or NORMAL, 2 for FULL, and 3 for EXTRA. Return 1 for an empty or
** unrecognized string argument. The FULL and EXTRA option is disallowed
** if the omitFull parameter it 1.
**
** Note that the values returned are one less that the values that
** should be passed into sqlite3BtreeSetSafetyLevel(). The is done
** to support legacy SQL code. The safety level used to be boolean
** and older scripts may have used numbers 0 for OFF and 1 for ON.
*/
static u8 getSafetyLevel(const char *z, int omitFull, u8 dflt){
/* 123456789 123456789 123 */
static const char zText[] = "onoffalseyestruextrafull";
static const u8 iOffset[] = {0, 1, 2, 4, 9, 12, 15, 20};
static const u8 iLength[] = {2, 2, 3, 5, 3, 4, 5, 4};
static const u8 iValue[] = {1, 0, 0, 0, 1, 1, 3, 2};
/* on no off false yes true extra full */
int i, n;
if( sqlite3Isdigit(*z) ){
return (u8)sqlite3Atoi(z);
}
n = sqlite3Strlen30(z);
for(i=0; i<ArraySize(iLength); i++){
if( iLength[i]==n && sqlite3StrNICmp(&zText[iOffset[i]],z,n)==0
&& (!omitFull || iValue[i]<=1)
){
return iValue[i];
}
}
return dflt;
}
/*
** Interpret the given string as a boolean value.
*/
SQLITE_PRIVATE u8 sqlite3GetBoolean(const char *z, u8 dflt){
return getSafetyLevel(z,1,dflt)!=0;
}
/* The sqlite3GetBoolean() function is used by other modules but the
** remainder of this file is specific to PRAGMA processing. So omit
** the rest of the file if PRAGMAs are omitted from the build.
*/
#if !defined(SQLITE_OMIT_PRAGMA)
/*
** Interpret the given string as a locking mode value.
*/
static int getLockingMode(const char *z){
if( z ){
if( 0==sqlite3StrICmp(z, "exclusive") ) return PAGER_LOCKINGMODE_EXCLUSIVE;
if( 0==sqlite3StrICmp(z, "normal") ) return PAGER_LOCKINGMODE_NORMAL;
}
return PAGER_LOCKINGMODE_QUERY;
}
#ifndef SQLITE_OMIT_AUTOVACUUM
/*
** Interpret the given string as an auto-vacuum mode value.
**
** The following strings, "none", "full" and "incremental" are
** acceptable, as are their numeric equivalents: 0, 1 and 2 respectively.
*/
static int getAutoVacuum(const char *z){
int i;
if( 0==sqlite3StrICmp(z, "none") ) return BTREE_AUTOVACUUM_NONE;
if( 0==sqlite3StrICmp(z, "full") ) return BTREE_AUTOVACUUM_FULL;
if( 0==sqlite3StrICmp(z, "incremental") ) return BTREE_AUTOVACUUM_INCR;
i = sqlite3Atoi(z);
return (u8)((i>=0&&i<=2)?i:0);
}
#endif /* ifndef SQLITE_OMIT_AUTOVACUUM */
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
/*
** Interpret the given string as a temp db location. Return 1 for file
** backed temporary databases, 2 for the Red-Black tree in memory database
** and 0 to use the compile-time default.
*/
static int getTempStore(const char *z){
if( z[0]>='0' && z[0]<='2' ){
return z[0] - '0';
}else if( sqlite3StrICmp(z, "file")==0 ){
return 1;
}else if( sqlite3StrICmp(z, "memory")==0 ){
return 2;
}else{
return 0;
}
}
#endif /* SQLITE_PAGER_PRAGMAS */
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
/*
** Invalidate temp storage, either when the temp storage is changed
** from default, or when 'file' and the temp_store_directory has changed
*/
static int invalidateTempStorage(Parse *pParse){
sqlite3 *db = pParse->db;
if( db->aDb[1].pBt!=0 ){
if( !db->autoCommit
|| sqlite3BtreeTxnState(db->aDb[1].pBt)!=SQLITE_TXN_NONE
){
sqlite3ErrorMsg(pParse, "temporary storage cannot be changed "
"from within a transaction");
return SQLITE_ERROR;
}
sqlite3BtreeClose(db->aDb[1].pBt);
db->aDb[1].pBt = 0;
sqlite3ResetAllSchemasOfConnection(db);
}
return SQLITE_OK;
}
#endif /* SQLITE_PAGER_PRAGMAS */
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
/*
** If the TEMP database is open, close it and mark the database schema
** as needing reloading. This must be done when using the SQLITE_TEMP_STORE
** or DEFAULT_TEMP_STORE pragmas.
*/
static int changeTempStorage(Parse *pParse, const char *zStorageType){
int ts = getTempStore(zStorageType);
sqlite3 *db = pParse->db;
if( db->temp_store==ts ) return SQLITE_OK;
if( invalidateTempStorage( pParse ) != SQLITE_OK ){
return SQLITE_ERROR;
}
db->temp_store = (u8)ts;
return SQLITE_OK;
}
#endif /* SQLITE_PAGER_PRAGMAS */
/*
** Set result column names for a pragma.
*/
static void setPragmaResultColumnNames(
Vdbe *v, /* The query under construction */
const PragmaName *pPragma /* The pragma */
){
u8 n = pPragma->nPragCName;
sqlite3VdbeSetNumCols(v, n==0 ? 1 : n);
if( n==0 ){
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, pPragma->zName, SQLITE_STATIC);
}else{
int i, j;
for(i=0, j=pPragma->iPragCName; i<n; i++, j++){
sqlite3VdbeSetColName(v, i, COLNAME_NAME, pragCName[j], SQLITE_STATIC);
}
}
}
/*
** Generate code to return a single integer value.
*/
static void returnSingleInt(Vdbe *v, i64 value){
sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, 1, 0, (const u8*)&value, P4_INT64);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
}
/*
** Generate code to return a single text value.
*/
static void returnSingleText(
Vdbe *v, /* Prepared statement under construction */
const char *zValue /* Value to be returned */
){
if( zValue ){
sqlite3VdbeLoadString(v, 1, (const char*)zValue);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
}
}
/*
** Set the safety_level and pager flags for pager iDb. Or if iDb<0
** set these values for all pagers.
*/
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
static void setAllPagerFlags(sqlite3 *db){
if( db->autoCommit ){
Db *pDb = db->aDb;
int n = db->nDb;
assert( SQLITE_FullFSync==PAGER_FULLFSYNC );
assert( SQLITE_CkptFullFSync==PAGER_CKPT_FULLFSYNC );
assert( SQLITE_CacheSpill==PAGER_CACHESPILL );
assert( (PAGER_FULLFSYNC | PAGER_CKPT_FULLFSYNC | PAGER_CACHESPILL)
== PAGER_FLAGS_MASK );
assert( (pDb->safety_level & PAGER_SYNCHRONOUS_MASK)==pDb->safety_level );
while( (n--) > 0 ){
if( pDb->pBt ){
sqlite3BtreeSetPagerFlags(pDb->pBt,
pDb->safety_level | (db->flags & PAGER_FLAGS_MASK) );
}
pDb++;
}
}
}
#else
# define setAllPagerFlags(X) /* no-op */
#endif
/*
** Return a human-readable name for a constraint resolution action.
*/
#ifndef SQLITE_OMIT_FOREIGN_KEY
static const char *actionName(u8 action){
const char *zName;
switch( action ){
case OE_SetNull: zName = "SET NULL"; break;
case OE_SetDflt: zName = "SET DEFAULT"; break;
case OE_Cascade: zName = "CASCADE"; break;
case OE_Restrict: zName = "RESTRICT"; break;
default: zName = "NO ACTION";
assert( action==OE_None ); break;
}
return zName;
}
#endif
/*
** Parameter eMode must be one of the PAGER_JOURNALMODE_XXX constants
** defined in pager.h. This function returns the associated lowercase
** journal-mode name.
*/
SQLITE_PRIVATE const char *sqlite3JournalModename(int eMode){
static char * const azModeName[] = {
"delete", "persist", "off", "truncate", "memory"
#ifndef SQLITE_OMIT_WAL
, "wal"
#endif
};
assert( PAGER_JOURNALMODE_DELETE==0 );
assert( PAGER_JOURNALMODE_PERSIST==1 );
assert( PAGER_JOURNALMODE_OFF==2 );
assert( PAGER_JOURNALMODE_TRUNCATE==3 );
assert( PAGER_JOURNALMODE_MEMORY==4 );
assert( PAGER_JOURNALMODE_WAL==5 );
assert( eMode>=0 && eMode<=ArraySize(azModeName) );
if( eMode==ArraySize(azModeName) ) return 0;
return azModeName[eMode];
}
/*
** Locate a pragma in the aPragmaName[] array.
*/
static const PragmaName *pragmaLocate(const char *zName){
int upr, lwr, mid = 0, rc;
lwr = 0;
upr = ArraySize(aPragmaName)-1;
while( lwr<=upr ){
mid = (lwr+upr)/2;
rc = sqlite3_stricmp(zName, aPragmaName[mid].zName);
if( rc==0 ) break;
if( rc<0 ){
upr = mid - 1;
}else{
lwr = mid + 1;
}
}
return lwr>upr ? 0 : &aPragmaName[mid];
}
/*
** Create zero or more entries in the output for the SQL functions
** defined by FuncDef p.
*/
static void pragmaFunclistLine(
Vdbe *v, /* The prepared statement being created */
FuncDef *p, /* A particular function definition */
int isBuiltin, /* True if this is a built-in function */
int showInternFuncs /* True if showing internal functions */
){
for(; p; p=p->pNext){
const char *zType;
static const u32 mask =
SQLITE_DETERMINISTIC |
SQLITE_DIRECTONLY |
SQLITE_SUBTYPE |
SQLITE_INNOCUOUS |
SQLITE_FUNC_INTERNAL
;
static const char *azEnc[] = { 0, "utf8", "utf16le", "utf16be" };
assert( SQLITE_FUNC_ENCMASK==0x3 );
assert( strcmp(azEnc[SQLITE_UTF8],"utf8")==0 );
assert( strcmp(azEnc[SQLITE_UTF16LE],"utf16le")==0 );
assert( strcmp(azEnc[SQLITE_UTF16BE],"utf16be")==0 );
if( p->xSFunc==0 ) continue;
if( (p->funcFlags & SQLITE_FUNC_INTERNAL)!=0
&& showInternFuncs==0
){
continue;
}
if( p->xValue!=0 ){
zType = "w";
}else if( p->xFinalize!=0 ){
zType = "a";
}else{
zType = "s";
}
sqlite3VdbeMultiLoad(v, 1, "sissii",
p->zName, isBuiltin,
zType, azEnc[p->funcFlags&SQLITE_FUNC_ENCMASK],
p->nArg,
(p->funcFlags & mask) ^ SQLITE_INNOCUOUS
);
}
}
/*
** Helper subroutine for PRAGMA integrity_check:
**
** Generate code to output a single-column result row with a value of the
** string held in register 3. Decrement the result count in register 1
** and halt if the maximum number of result rows have been issued.
*/
static int integrityCheckResultRow(Vdbe *v){
int addr;
sqlite3VdbeAddOp2(v, OP_ResultRow, 3, 1);
addr = sqlite3VdbeAddOp3(v, OP_IfPos, 1, sqlite3VdbeCurrentAddr(v)+2, 1);
VdbeCoverage(v);
sqlite3VdbeAddOp0(v, OP_Halt);
return addr;
}
/*
** Process a pragma statement.
**
** Pragmas are of this form:
**
** PRAGMA [schema.]id [= value]
**
** The identifier might also be a string. The value is a string, and
** identifier, or a number. If minusFlag is true, then the value is
** a number that was preceded by a minus sign.
**
** If the left side is "database.id" then pId1 is the database name
** and pId2 is the id. If the left side is just "id" then pId1 is the
** id and pId2 is any empty string.
*/
SQLITE_PRIVATE void sqlite3Pragma(
Parse *pParse,
Token *pId1, /* First part of [schema.]id field */
Token *pId2, /* Second part of [schema.]id field, or NULL */
Token *pValue, /* Token for <value>, or NULL */
int minusFlag /* True if a '-' sign preceded <value> */
){
char *zLeft = 0; /* Nul-terminated UTF-8 string <id> */
char *zRight = 0; /* Nul-terminated UTF-8 string <value>, or NULL */
const char *zDb = 0; /* The database name */
Token *pId; /* Pointer to <id> token */
char *aFcntl[4]; /* Argument to SQLITE_FCNTL_PRAGMA */
int iDb; /* Database index for <database> */
int rc; /* return value form SQLITE_FCNTL_PRAGMA */
sqlite3 *db = pParse->db; /* The database connection */
Db *pDb; /* The specific database being pragmaed */
Vdbe *v = sqlite3GetVdbe(pParse); /* Prepared statement */
const PragmaName *pPragma; /* The pragma */
if( v==0 ) return;
sqlite3VdbeRunOnlyOnce(v);
pParse->nMem = 2;
/* Interpret the [schema.] part of the pragma statement. iDb is the
** index of the database this pragma is being applied to in db.aDb[]. */
iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
if( iDb<0 ) return;
pDb = &db->aDb[iDb];
/* If the temp database has been explicitly named as part of the
** pragma, make sure it is open.
*/
if( iDb==1 && sqlite3OpenTempDatabase(pParse) ){
return;
}
zLeft = sqlite3NameFromToken(db, pId);
if( !zLeft ) return;
if( minusFlag ){
zRight = sqlite3MPrintf(db, "-%T", pValue);
}else{
zRight = sqlite3NameFromToken(db, pValue);
}
assert( pId2 );
zDb = pId2->n>0 ? pDb->zDbSName : 0;
if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){
goto pragma_out;
}
/* Send an SQLITE_FCNTL_PRAGMA file-control to the underlying VFS
** connection. If it returns SQLITE_OK, then assume that the VFS
** handled the pragma and generate a no-op prepared statement.
**
** IMPLEMENTATION-OF: R-12238-55120 Whenever a PRAGMA statement is parsed,
** an SQLITE_FCNTL_PRAGMA file control is sent to the open sqlite3_file
** object corresponding to the database file to which the pragma
** statement refers.
**
** IMPLEMENTATION-OF: R-29875-31678 The argument to the SQLITE_FCNTL_PRAGMA
** file control is an array of pointers to strings (char**) in which the
** second element of the array is the name of the pragma and the third
** element is the argument to the pragma or NULL if the pragma has no
** argument.
*/
aFcntl[0] = 0;
aFcntl[1] = zLeft;
aFcntl[2] = zRight;
aFcntl[3] = 0;
db->busyHandler.nBusy = 0;
rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_PRAGMA, (void*)aFcntl);
if( rc==SQLITE_OK ){
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, aFcntl[0], SQLITE_TRANSIENT);
returnSingleText(v, aFcntl[0]);
sqlite3_free(aFcntl[0]);
goto pragma_out;
}
if( rc!=SQLITE_NOTFOUND ){
if( aFcntl[0] ){
sqlite3ErrorMsg(pParse, "%s", aFcntl[0]);
sqlite3_free(aFcntl[0]);
}
pParse->nErr++;
pParse->rc = rc;
goto pragma_out;
}
/* Locate the pragma in the lookup table */
pPragma = pragmaLocate(zLeft);
if( pPragma==0 ) goto pragma_out;
/* Make sure the database schema is loaded if the pragma requires that */
if( (pPragma->mPragFlg & PragFlg_NeedSchema)!=0 ){
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
}
/* Register the result column names for pragmas that return results */
if( (pPragma->mPragFlg & PragFlg_NoColumns)==0
&& ((pPragma->mPragFlg & PragFlg_NoColumns1)==0 || zRight==0)
){
setPragmaResultColumnNames(v, pPragma);
}
/* Jump to the appropriate pragma handler */
switch( pPragma->ePragTyp ){
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && !defined(SQLITE_OMIT_DEPRECATED)
/*
** PRAGMA [schema.]default_cache_size
** PRAGMA [schema.]default_cache_size=N
**
** The first form reports the current persistent setting for the
** page cache size. The value returned is the maximum number of
** pages in the page cache. The second form sets both the current
** page cache size value and the persistent page cache size value
** stored in the database file.
**
** Older versions of SQLite would set the default cache size to a
** negative number to indicate synchronous=OFF. These days, synchronous
** is always on by default regardless of the sign of the default cache
** size. But continue to take the absolute value of the default cache
** size of historical compatibility.
*/
case PragTyp_DEFAULT_CACHE_SIZE: {
static const int iLn = VDBE_OFFSET_LINENO(2);
static const VdbeOpList getCacheSize[] = {
{ OP_Transaction, 0, 0, 0}, /* 0 */
{ OP_ReadCookie, 0, 1, BTREE_DEFAULT_CACHE_SIZE}, /* 1 */
{ OP_IfPos, 1, 8, 0},
{ OP_Integer, 0, 2, 0},
{ OP_Subtract, 1, 2, 1},
{ OP_IfPos, 1, 8, 0},
{ OP_Integer, 0, 1, 0}, /* 6 */
{ OP_Noop, 0, 0, 0},
{ OP_ResultRow, 1, 1, 0},
};
VdbeOp *aOp;
sqlite3VdbeUsesBtree(v, iDb);
if( !zRight ){
pParse->nMem += 2;
sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(getCacheSize));
aOp = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize, iLn);
if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
aOp[0].p1 = iDb;
aOp[1].p1 = iDb;
aOp[6].p1 = SQLITE_DEFAULT_CACHE_SIZE;
}else{
int size = sqlite3AbsInt32(sqlite3Atoi(zRight));
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, size);
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
pDb->pSchema->cache_size = size;
sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
}
break;
}
#endif /* !SQLITE_OMIT_PAGER_PRAGMAS && !SQLITE_OMIT_DEPRECATED */
#if !defined(SQLITE_OMIT_PAGER_PRAGMAS)
/*
** PRAGMA [schema.]page_size
** PRAGMA [schema.]page_size=N
**
** The first form reports the current setting for the
** database page size in bytes. The second form sets the
** database page size value. The value can only be set if
** the database has not yet been created.
*/
case PragTyp_PAGE_SIZE: {
Btree *pBt = pDb->pBt;
assert( pBt!=0 );
if( !zRight ){
int size = ALWAYS(pBt) ? sqlite3BtreeGetPageSize(pBt) : 0;
returnSingleInt(v, size);
}else{
/* Malloc may fail when setting the page-size, as there is an internal
** buffer that the pager module resizes using sqlite3_realloc().
*/
db->nextPagesize = sqlite3Atoi(zRight);
if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize,0,0) ){
sqlite3OomFault(db);
}
}
break;
}
/*
** PRAGMA [schema.]secure_delete
** PRAGMA [schema.]secure_delete=ON/OFF/FAST
**
** The first form reports the current setting for the
** secure_delete flag. The second form changes the secure_delete
** flag setting and reports the new value.
*/
case PragTyp_SECURE_DELETE: {
Btree *pBt = pDb->pBt;
int b = -1;
assert( pBt!=0 );
if( zRight ){
if( sqlite3_stricmp(zRight, "fast")==0 ){
b = 2;
}else{
b = sqlite3GetBoolean(zRight, 0);
}
}
if( pId2->n==0 && b>=0 ){
int ii;
for(ii=0; ii<db->nDb; ii++){
sqlite3BtreeSecureDelete(db->aDb[ii].pBt, b);
}
}
b = sqlite3BtreeSecureDelete(pBt, b);
returnSingleInt(v, b);
break;
}
/*
** PRAGMA [schema.]max_page_count
** PRAGMA [schema.]max_page_count=N
**
** The first form reports the current setting for the
** maximum number of pages in the database file. The
** second form attempts to change this setting. Both
** forms return the current setting.
**
** The absolute value of N is used. This is undocumented and might
** change. The only purpose is to provide an easy way to test
** the sqlite3AbsInt32() function.
**
** PRAGMA [schema.]page_count
**
** Return the number of pages in the specified database.
*/
case PragTyp_PAGE_COUNT: {
int iReg;
i64 x = 0;
sqlite3CodeVerifySchema(pParse, iDb);
iReg = ++pParse->nMem;
if( sqlite3Tolower(zLeft[0])=='p' ){
sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg);
}else{
if( zRight && sqlite3DecOrHexToI64(zRight,&x)==0 ){
if( x<0 ) x = 0;
else if( x>0xfffffffe ) x = 0xfffffffe;
}else{
x = 0;
}
sqlite3VdbeAddOp3(v, OP_MaxPgcnt, iDb, iReg, (int)x);
}
sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1);
break;
}
/*
** PRAGMA [schema.]locking_mode
** PRAGMA [schema.]locking_mode = (normal|exclusive)
*/
case PragTyp_LOCKING_MODE: {
const char *zRet = "normal";
int eMode = getLockingMode(zRight);
if( pId2->n==0 && eMode==PAGER_LOCKINGMODE_QUERY ){
/* Simple "PRAGMA locking_mode;" statement. This is a query for
** the current default locking mode (which may be different to
** the locking-mode of the main database).
*/
eMode = db->dfltLockMode;
}else{
Pager *pPager;
if( pId2->n==0 ){
/* This indicates that no database name was specified as part
** of the PRAGMA command. In this case the locking-mode must be
** set on all attached databases, as well as the main db file.
**
** Also, the sqlite3.dfltLockMode variable is set so that
** any subsequently attached databases also use the specified
** locking mode.
*/
int ii;
assert(pDb==&db->aDb[0]);
for(ii=2; ii<db->nDb; ii++){
pPager = sqlite3BtreePager(db->aDb[ii].pBt);
sqlite3PagerLockingMode(pPager, eMode);
}
db->dfltLockMode = (u8)eMode;
}
pPager = sqlite3BtreePager(pDb->pBt);
eMode = sqlite3PagerLockingMode(pPager, eMode);
}
assert( eMode==PAGER_LOCKINGMODE_NORMAL
|| eMode==PAGER_LOCKINGMODE_EXCLUSIVE );
if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
zRet = "exclusive";
}
returnSingleText(v, zRet);
break;
}
/*
** PRAGMA [schema.]journal_mode
** PRAGMA [schema.]journal_mode =
** (delete|persist|off|truncate|memory|wal|off)
*/
case PragTyp_JOURNAL_MODE: {
int eMode; /* One of the PAGER_JOURNALMODE_XXX symbols */
int ii; /* Loop counter */
if( zRight==0 ){
/* If there is no "=MODE" part of the pragma, do a query for the
** current mode */
eMode = PAGER_JOURNALMODE_QUERY;
}else{
const char *zMode;
int n = sqlite3Strlen30(zRight);
for(eMode=0; (zMode = sqlite3JournalModename(eMode))!=0; eMode++){
if( sqlite3StrNICmp(zRight, zMode, n)==0 ) break;
}
if( !zMode ){
/* If the "=MODE" part does not match any known journal mode,
** then do a query */
eMode = PAGER_JOURNALMODE_QUERY;
}
if( eMode==PAGER_JOURNALMODE_OFF && (db->flags & SQLITE_Defensive)!=0 ){
/* Do not allow journal-mode "OFF" in defensive since the database
** can become corrupted using ordinary SQL when the journal is off */
eMode = PAGER_JOURNALMODE_QUERY;
}
}
if( eMode==PAGER_JOURNALMODE_QUERY && pId2->n==0 ){
/* Convert "PRAGMA journal_mode" into "PRAGMA main.journal_mode" */
iDb = 0;
pId2->n = 1;
}
for(ii=db->nDb-1; ii>=0; ii--){
if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
sqlite3VdbeUsesBtree(v, ii);
sqlite3VdbeAddOp3(v, OP_JournalMode, ii, 1, eMode);
}
}
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
break;
}
/*
** PRAGMA [schema.]journal_size_limit
** PRAGMA [schema.]journal_size_limit=N
**
** Get or set the size limit on rollback journal files.
*/
case PragTyp_JOURNAL_SIZE_LIMIT: {
Pager *pPager = sqlite3BtreePager(pDb->pBt);
i64 iLimit = -2;
if( zRight ){
sqlite3DecOrHexToI64(zRight, &iLimit);
if( iLimit<-1 ) iLimit = -1;
}
iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit);
returnSingleInt(v, iLimit);
break;
}
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */
/*
** PRAGMA [schema.]auto_vacuum
** PRAGMA [schema.]auto_vacuum=N
**
** Get or set the value of the database 'auto-vacuum' parameter.
** The value is one of: 0 NONE 1 FULL 2 INCREMENTAL
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
case PragTyp_AUTO_VACUUM: {
Btree *pBt = pDb->pBt;
assert( pBt!=0 );
if( !zRight ){
returnSingleInt(v, sqlite3BtreeGetAutoVacuum(pBt));
}else{
int eAuto = getAutoVacuum(zRight);
assert( eAuto>=0 && eAuto<=2 );
db->nextAutovac = (u8)eAuto;
/* Call SetAutoVacuum() to set initialize the internal auto and
** incr-vacuum flags. This is required in case this connection
** creates the database file. It is important that it is created
** as an auto-vacuum capable db.
*/
rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto);
if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){
/* When setting the auto_vacuum mode to either "full" or
** "incremental", write the value of meta[6] in the database
** file. Before writing to meta[6], check that meta[3] indicates
** that this really is an auto-vacuum capable database.
*/
static const int iLn = VDBE_OFFSET_LINENO(2);
static const VdbeOpList setMeta6[] = {
{ OP_Transaction, 0, 1, 0}, /* 0 */
{ OP_ReadCookie, 0, 1, BTREE_LARGEST_ROOT_PAGE},
{ OP_If, 1, 0, 0}, /* 2 */
{ OP_Halt, SQLITE_OK, OE_Abort, 0}, /* 3 */
{ OP_SetCookie, 0, BTREE_INCR_VACUUM, 0}, /* 4 */
};
VdbeOp *aOp;
int iAddr = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setMeta6));
aOp = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn);
if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
aOp[0].p1 = iDb;
aOp[1].p1 = iDb;
aOp[2].p2 = iAddr+4;
aOp[4].p1 = iDb;
aOp[4].p3 = eAuto - 1;
sqlite3VdbeUsesBtree(v, iDb);
}
}
break;
}
#endif
/*
** PRAGMA [schema.]incremental_vacuum(N)
**
** Do N steps of incremental vacuuming on a database.
*/
#ifndef SQLITE_OMIT_AUTOVACUUM
case PragTyp_INCREMENTAL_VACUUM: {
int iLimit, addr;
if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
iLimit = 0x7fffffff;
}
sqlite3BeginWriteOperation(pParse, 0, iDb);
sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);
addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb); VdbeCoverage(v);
sqlite3VdbeAddOp1(v, OP_ResultRow, 1);
sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addr);
break;
}
#endif
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
/*
** PRAGMA [schema.]cache_size
** PRAGMA [schema.]cache_size=N
**
** The first form reports the current local setting for the
** page cache size. The second form sets the local
** page cache size value. If N is positive then that is the
** number of pages in the cache. If N is negative, then the
** number of pages is adjusted so that the cache uses -N kibibytes
** of memory.
*/
case PragTyp_CACHE_SIZE: {
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( !zRight ){
returnSingleInt(v, pDb->pSchema->cache_size);
}else{
int size = sqlite3Atoi(zRight);
pDb->pSchema->cache_size = size;
sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
}
break;
}
/*
** PRAGMA [schema.]cache_spill
** PRAGMA cache_spill=BOOLEAN
** PRAGMA [schema.]cache_spill=N
**
** The first form reports the current local setting for the
** page cache spill size. The second form turns cache spill on
** or off. When turnning cache spill on, the size is set to the
** current cache_size. The third form sets a spill size that
** may be different form the cache size.
** If N is positive then that is the
** number of pages in the cache. If N is negative, then the
** number of pages is adjusted so that the cache uses -N kibibytes
** of memory.
**
** If the number of cache_spill pages is less then the number of
** cache_size pages, no spilling occurs until the page count exceeds
** the number of cache_size pages.
**
** The cache_spill=BOOLEAN setting applies to all attached schemas,
** not just the schema specified.
*/
case PragTyp_CACHE_SPILL: {
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( !zRight ){
returnSingleInt(v,
(db->flags & SQLITE_CacheSpill)==0 ? 0 :
sqlite3BtreeSetSpillSize(pDb->pBt,0));
}else{
int size = 1;
if( sqlite3GetInt32(zRight, &size) ){
sqlite3BtreeSetSpillSize(pDb->pBt, size);
}
if( sqlite3GetBoolean(zRight, size!=0) ){
db->flags |= SQLITE_CacheSpill;
}else{
db->flags &= ~(u64)SQLITE_CacheSpill;
}
setAllPagerFlags(db);
}
break;
}
/*
** PRAGMA [schema.]mmap_size(N)
**
** Used to set mapping size limit. The mapping size limit is
** used to limit the aggregate size of all memory mapped regions of the
** database file. If this parameter is set to zero, then memory mapping
** is not used at all. If N is negative, then the default memory map
** limit determined by sqlite3_config(SQLITE_CONFIG_MMAP_SIZE) is set.
** The parameter N is measured in bytes.
**
** This value is advisory. The underlying VFS is free to memory map
** as little or as much as it wants. Except, if N is set to 0 then the
** upper layers will never invoke the xFetch interfaces to the VFS.
*/
case PragTyp_MMAP_SIZE: {
sqlite3_int64 sz;
#if SQLITE_MAX_MMAP_SIZE>0
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( zRight ){
int ii;
sqlite3DecOrHexToI64(zRight, &sz);
if( sz<0 ) sz = sqlite3GlobalConfig.szMmap;
if( pId2->n==0 ) db->szMmap = sz;
for(ii=db->nDb-1; ii>=0; ii--){
if( db->aDb[ii].pBt && (ii==iDb || pId2->n==0) ){
sqlite3BtreeSetMmapLimit(db->aDb[ii].pBt, sz);
}
}
}
sz = -1;
rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_MMAP_SIZE, &sz);
#else
sz = 0;
rc = SQLITE_OK;
#endif
if( rc==SQLITE_OK ){
returnSingleInt(v, sz);
}else if( rc!=SQLITE_NOTFOUND ){
pParse->nErr++;
pParse->rc = rc;
}
break;
}
/*
** PRAGMA temp_store
** PRAGMA temp_store = "default"|"memory"|"file"
**
** Return or set the local value of the temp_store flag. Changing
** the local value does not make changes to the disk file and the default
** value will be restored the next time the database is opened.
**
** Note that it is possible for the library compile-time options to
** override this setting
*/
case PragTyp_TEMP_STORE: {
if( !zRight ){
returnSingleInt(v, db->temp_store);
}else{
changeTempStorage(pParse, zRight);
}
break;
}
/*
** PRAGMA temp_store_directory
** PRAGMA temp_store_directory = ""|"directory_name"
**
** Return or set the local value of the temp_store_directory flag. Changing
** the value sets a specific directory to be used for temporary files.
** Setting to a null string reverts to the default temporary directory search.
** If temporary directory is changed, then invalidateTempStorage.
**
*/
case PragTyp_TEMP_STORE_DIRECTORY: {
if( !zRight ){
returnSingleText(v, sqlite3_temp_directory);
}else{
#ifndef SQLITE_OMIT_WSD
if( zRight[0] ){
int res;
rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
if( rc!=SQLITE_OK || res==0 ){
sqlite3ErrorMsg(pParse, "not a writable directory");
goto pragma_out;
}
}
if( SQLITE_TEMP_STORE==0
|| (SQLITE_TEMP_STORE==1 && db->temp_store<=1)
|| (SQLITE_TEMP_STORE==2 && db->temp_store==1)
){
invalidateTempStorage(pParse);
}
sqlite3_free(sqlite3_temp_directory);
if( zRight[0] ){
sqlite3_temp_directory = sqlite3_mprintf("%s", zRight);
}else{
sqlite3_temp_directory = 0;
}
#endif /* SQLITE_OMIT_WSD */
}
break;
}
#if SQLITE_OS_WIN
/*
** PRAGMA data_store_directory
** PRAGMA data_store_directory = ""|"directory_name"
**
** Return or set the local value of the data_store_directory flag. Changing
** the value sets a specific directory to be used for database files that
** were specified with a relative pathname. Setting to a null string reverts
** to the default database directory, which for database files specified with
** a relative path will probably be based on the current directory for the
** process. Database file specified with an absolute path are not impacted
** by this setting, regardless of its value.
**
*/
case PragTyp_DATA_STORE_DIRECTORY: {
if( !zRight ){
returnSingleText(v, sqlite3_data_directory);
}else{
#ifndef SQLITE_OMIT_WSD
if( zRight[0] ){
int res;
rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res);
if( rc!=SQLITE_OK || res==0 ){
sqlite3ErrorMsg(pParse, "not a writable directory");
goto pragma_out;
}
}
sqlite3_free(sqlite3_data_directory);
if( zRight[0] ){
sqlite3_data_directory = sqlite3_mprintf("%s", zRight);
}else{
sqlite3_data_directory = 0;
}
#endif /* SQLITE_OMIT_WSD */
}
break;
}
#endif
#if SQLITE_ENABLE_LOCKING_STYLE
/*
** PRAGMA [schema.]lock_proxy_file
** PRAGMA [schema.]lock_proxy_file = ":auto:"|"lock_file_path"
**
** Return or set the value of the lock_proxy_file flag. Changing
** the value sets a specific file to be used for database access locks.
**
*/
case PragTyp_LOCK_PROXY_FILE: {
if( !zRight ){
Pager *pPager = sqlite3BtreePager(pDb->pBt);
char *proxy_file_path = NULL;
sqlite3_file *pFile = sqlite3PagerFile(pPager);
sqlite3OsFileControlHint(pFile, SQLITE_GET_LOCKPROXYFILE,
&proxy_file_path);
returnSingleText(v, proxy_file_path);
}else{
Pager *pPager = sqlite3BtreePager(pDb->pBt);
sqlite3_file *pFile = sqlite3PagerFile(pPager);
int res;
if( zRight[0] ){
res=sqlite3OsFileControl(pFile, SQLITE_SET_LOCKPROXYFILE,
zRight);
} else {
res=sqlite3OsFileControl(pFile, SQLITE_SET_LOCKPROXYFILE,
NULL);
}
if( res!=SQLITE_OK ){
sqlite3ErrorMsg(pParse, "failed to set lock proxy file");
goto pragma_out;
}
}
break;
}
#endif /* SQLITE_ENABLE_LOCKING_STYLE */
/*
** PRAGMA [schema.]synchronous
** PRAGMA [schema.]synchronous=OFF|ON|NORMAL|FULL|EXTRA
**
** Return or set the local value of the synchronous flag. Changing
** the local value does not make changes to the disk file and the
** default value will be restored the next time the database is
** opened.
*/
case PragTyp_SYNCHRONOUS: {
if( !zRight ){
returnSingleInt(v, pDb->safety_level-1);
}else{
if( !db->autoCommit ){
sqlite3ErrorMsg(pParse,
"Safety level may not be changed inside a transaction");
}else if( iDb!=1 ){
int iLevel = (getSafetyLevel(zRight,0,1)+1) & PAGER_SYNCHRONOUS_MASK;
if( iLevel==0 ) iLevel = 1;
pDb->safety_level = iLevel;
pDb->bSyncSet = 1;
setAllPagerFlags(db);
}
}
break;
}
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */
#ifndef SQLITE_OMIT_FLAG_PRAGMAS
case PragTyp_FLAG: {
if( zRight==0 ){
setPragmaResultColumnNames(v, pPragma);
returnSingleInt(v, (db->flags & pPragma->iArg)!=0 );
}else{
u64 mask = pPragma->iArg; /* Mask of bits to set or clear. */
if( db->autoCommit==0 ){
/* Foreign key support may not be enabled or disabled while not
** in auto-commit mode. */
mask &= ~(SQLITE_ForeignKeys);
}
#if SQLITE_USER_AUTHENTICATION
if( db->auth.authLevel==UAUTH_User ){
/* Do not allow non-admin users to modify the schema arbitrarily */
mask &= ~(SQLITE_WriteSchema);
}
#endif
if( sqlite3GetBoolean(zRight, 0) ){
db->flags |= mask;
}else{
db->flags &= ~mask;
if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
}
/* Many of the flag-pragmas modify the code generated by the SQL
** compiler (eg. count_changes). So add an opcode to expire all
** compiled SQL statements after modifying a pragma value.
*/
sqlite3VdbeAddOp0(v, OP_Expire);
setAllPagerFlags(db);
}
break;
}
#endif /* SQLITE_OMIT_FLAG_PRAGMAS */
#ifndef SQLITE_OMIT_SCHEMA_PRAGMAS
/*
** PRAGMA table_info(<table>)
**
** Return a single row for each column of the named table. The columns of
** the returned data set are:
**
** cid: Column id (numbered from left to right, starting at 0)
** name: Column name
** type: Column declaration type.
** notnull: True if 'NOT NULL' is part of column declaration
** dflt_value: The default value for the column, if any.
** pk: Non-zero for PK fields.
*/
case PragTyp_TABLE_INFO: if( zRight ){
Table *pTab;
sqlite3CodeVerifyNamedSchema(pParse, zDb);
pTab = sqlite3LocateTable(pParse, LOCATE_NOERR, zRight, zDb);
if( pTab ){
int i, k;
int nHidden = 0;
Column *pCol;
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
pParse->nMem = 7;
sqlite3ViewGetColumnNames(pParse, pTab);
for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
int isHidden = 0;
if( pCol->colFlags & COLFLAG_NOINSERT ){
if( pPragma->iArg==0 ){
nHidden++;
continue;
}
if( pCol->colFlags & COLFLAG_VIRTUAL ){
isHidden = 2; /* GENERATED ALWAYS AS ... VIRTUAL */
}else if( pCol->colFlags & COLFLAG_STORED ){
isHidden = 3; /* GENERATED ALWAYS AS ... STORED */
}else{ assert( pCol->colFlags & COLFLAG_HIDDEN );
isHidden = 1; /* HIDDEN */
}
}
if( (pCol->colFlags & COLFLAG_PRIMKEY)==0 ){
k = 0;
}else if( pPk==0 ){
k = 1;
}else{
for(k=1; k<=pTab->nCol && pPk->aiColumn[k-1]!=i; k++){}
}
assert( pCol->pDflt==0 || pCol->pDflt->op==TK_SPAN || isHidden>=2 );
sqlite3VdbeMultiLoad(v, 1, pPragma->iArg ? "issisii" : "issisi",
i-nHidden,
pCol->zName,
sqlite3ColumnType(pCol,""),
pCol->notNull ? 1 : 0,
pCol->pDflt && isHidden<2 ? pCol->pDflt->u.zToken : 0,
k,
isHidden);
}
}
}
break;
#ifdef SQLITE_DEBUG
case PragTyp_STATS: {
Index *pIdx;
HashElem *i;
pParse->nMem = 5;
sqlite3CodeVerifySchema(pParse, iDb);
for(i=sqliteHashFirst(&pDb->pSchema->tblHash); i; i=sqliteHashNext(i)){
Table *pTab = sqliteHashData(i);
sqlite3VdbeMultiLoad(v, 1, "ssiii",
pTab->zName,
0,
pTab->szTabRow,
pTab->nRowLogEst,
pTab->tabFlags);
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
sqlite3VdbeMultiLoad(v, 2, "siiiX",
pIdx->zName,
pIdx->szIdxRow,
pIdx->aiRowLogEst[0],
pIdx->hasStat1);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 5);
}
}
}
break;
#endif
case PragTyp_INDEX_INFO: if( zRight ){
Index *pIdx;
Table *pTab;
pIdx = sqlite3FindIndex(db, zRight, zDb);
if( pIdx==0 ){
/* If there is no index named zRight, check to see if there is a
** WITHOUT ROWID table named zRight, and if there is, show the
** structure of the PRIMARY KEY index for that table. */
pTab = sqlite3LocateTable(pParse, LOCATE_NOERR, zRight, zDb);
if( pTab && !HasRowid(pTab) ){
pIdx = sqlite3PrimaryKeyIndex(pTab);
}
}
if( pIdx ){
int iIdxDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
int i;
int mx;
if( pPragma->iArg ){
/* PRAGMA index_xinfo (newer version with more rows and columns) */
mx = pIdx->nColumn;
pParse->nMem = 6;
}else{
/* PRAGMA index_info (legacy version) */
mx = pIdx->nKeyCol;
pParse->nMem = 3;
}
pTab = pIdx->pTable;
sqlite3CodeVerifySchema(pParse, iIdxDb);
assert( pParse->nMem<=pPragma->nPragCName );
for(i=0; i<mx; i++){
i16 cnum = pIdx->aiColumn[i];
sqlite3VdbeMultiLoad(v, 1, "iisX", i, cnum,
cnum<0 ? 0 : pTab->aCol[cnum].zName);
if( pPragma->iArg ){
sqlite3VdbeMultiLoad(v, 4, "isiX",
pIdx->aSortOrder[i],
pIdx->azColl[i],
i<pIdx->nKeyCol);
}
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, pParse->nMem);
}
}
}
break;
case PragTyp_INDEX_LIST: if( zRight ){
Index *pIdx;
Table *pTab;
int i;
pTab = sqlite3FindTable(db, zRight, zDb);
if( pTab ){
int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
pParse->nMem = 5;
sqlite3CodeVerifySchema(pParse, iTabDb);
for(pIdx=pTab->pIndex, i=0; pIdx; pIdx=pIdx->pNext, i++){
const char *azOrigin[] = { "c", "u", "pk" };
sqlite3VdbeMultiLoad(v, 1, "isisi",
i,
pIdx->zName,
IsUniqueIndex(pIdx),
azOrigin[pIdx->idxType],
pIdx->pPartIdxWhere!=0);
}
}
}
break;
case PragTyp_DATABASE_LIST: {
int i;
pParse->nMem = 3;
for(i=0; i<db->nDb; i++){
if( db->aDb[i].pBt==0 ) continue;
assert( db->aDb[i].zDbSName!=0 );
sqlite3VdbeMultiLoad(v, 1, "iss",
i,
db->aDb[i].zDbSName,
sqlite3BtreeGetFilename(db->aDb[i].pBt));
}
}
break;
case PragTyp_COLLATION_LIST: {
int i = 0;
HashElem *p;
pParse->nMem = 2;
for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
CollSeq *pColl = (CollSeq *)sqliteHashData(p);
sqlite3VdbeMultiLoad(v, 1, "is", i++, pColl->zName);
}
}
break;
#ifndef SQLITE_OMIT_INTROSPECTION_PRAGMAS
case PragTyp_FUNCTION_LIST: {
int i;
HashElem *j;
FuncDef *p;
int showInternFunc = (db->mDbFlags & DBFLAG_InternalFunc)!=0;
pParse->nMem = 6;
for(i=0; i<SQLITE_FUNC_HASH_SZ; i++){
for(p=sqlite3BuiltinFunctions.a[i]; p; p=p->u.pHash ){
pragmaFunclistLine(v, p, 1, showInternFunc);
}
}
for(j=sqliteHashFirst(&db->aFunc); j; j=sqliteHashNext(j)){
p = (FuncDef*)sqliteHashData(j);
pragmaFunclistLine(v, p, 0, showInternFunc);
}
}
break;
#ifndef SQLITE_OMIT_VIRTUALTABLE
case PragTyp_MODULE_LIST: {
HashElem *j;
pParse->nMem = 1;
for(j=sqliteHashFirst(&db->aModule); j; j=sqliteHashNext(j)){
Module *pMod = (Module*)sqliteHashData(j);
sqlite3VdbeMultiLoad(v, 1, "s", pMod->zName);
}
}
break;
#endif /* SQLITE_OMIT_VIRTUALTABLE */
case PragTyp_PRAGMA_LIST: {
int i;
for(i=0; i<ArraySize(aPragmaName); i++){
sqlite3VdbeMultiLoad(v, 1, "s", aPragmaName[i].zName);
}
}
break;
#endif /* SQLITE_INTROSPECTION_PRAGMAS */
#endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */
#ifndef SQLITE_OMIT_FOREIGN_KEY
case PragTyp_FOREIGN_KEY_LIST: if( zRight ){
FKey *pFK;
Table *pTab;
pTab = sqlite3FindTable(db, zRight, zDb);
if( pTab ){
pFK = pTab->pFKey;
if( pFK ){
int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
int i = 0;
pParse->nMem = 8;
sqlite3CodeVerifySchema(pParse, iTabDb);
while(pFK){
int j;
for(j=0; j<pFK->nCol; j++){
sqlite3VdbeMultiLoad(v, 1, "iissssss",
i,
j,
pFK->zTo,
pTab->aCol[pFK->aCol[j].iFrom].zName,
pFK->aCol[j].zCol,
actionName(pFK->aAction[1]), /* ON UPDATE */
actionName(pFK->aAction[0]), /* ON DELETE */
"NONE");
}
++i;
pFK = pFK->pNextFrom;
}
}
}
}
break;
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
#ifndef SQLITE_OMIT_FOREIGN_KEY
#ifndef SQLITE_OMIT_TRIGGER
case PragTyp_FOREIGN_KEY_CHECK: {
FKey *pFK; /* A foreign key constraint */
Table *pTab; /* Child table contain "REFERENCES" keyword */
Table *pParent; /* Parent table that child points to */
Index *pIdx; /* Index in the parent table */
int i; /* Loop counter: Foreign key number for pTab */
int j; /* Loop counter: Field of the foreign key */
HashElem *k; /* Loop counter: Next table in schema */
int x; /* result variable */
int regResult; /* 3 registers to hold a result row */
int regKey; /* Register to hold key for checking the FK */
int regRow; /* Registers to hold a row from pTab */
int addrTop; /* Top of a loop checking foreign keys */
int addrOk; /* Jump here if the key is OK */
int *aiCols; /* child to parent column mapping */
regResult = pParse->nMem+1;
pParse->nMem += 4;
regKey = ++pParse->nMem;
regRow = ++pParse->nMem;
k = sqliteHashFirst(&db->aDb[iDb].pSchema->tblHash);
while( k ){
if( zRight ){
pTab = sqlite3LocateTable(pParse, 0, zRight, zDb);
k = 0;
}else{
pTab = (Table*)sqliteHashData(k);
k = sqliteHashNext(k);
}
if( pTab==0 || pTab->pFKey==0 ) continue;
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
zDb = db->aDb[iDb].zDbSName;
sqlite3CodeVerifySchema(pParse, iDb);
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
if( pTab->nCol+regRow>pParse->nMem ) pParse->nMem = pTab->nCol + regRow;
sqlite3OpenTable(pParse, 0, iDb, pTab, OP_OpenRead);
sqlite3VdbeLoadString(v, regResult, pTab->zName);
for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
pParent = sqlite3FindTable(db, pFK->zTo, zDb);
if( pParent==0 ) continue;
pIdx = 0;
sqlite3TableLock(pParse, iDb, pParent->tnum, 0, pParent->zName);
x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, 0);
if( x==0 ){
if( pIdx==0 ){
sqlite3OpenTable(pParse, i, iDb, pParent, OP_OpenRead);
}else{
sqlite3VdbeAddOp3(v, OP_OpenRead, i, pIdx->tnum, iDb);
sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
}
}else{
k = 0;
break;
}
}
assert( pParse->nErr>0 || pFK==0 );
if( pFK ) break;
if( pParse->nTab<i ) pParse->nTab = i;
addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, 0); VdbeCoverage(v);
for(i=1, pFK=pTab->pFKey; pFK; i++, pFK=pFK->pNextFrom){
pParent = sqlite3FindTable(db, pFK->zTo, zDb);
pIdx = 0;
aiCols = 0;
if( pParent ){
x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, &aiCols);
assert( x==0 || db->mallocFailed );
}
addrOk = sqlite3VdbeMakeLabel(pParse);
/* Generate code to read the child key values into registers
** regRow..regRow+n. If any of the child key values are NULL, this
** row cannot cause an FK violation. Jump directly to addrOk in
** this case. */
for(j=0; j<pFK->nCol; j++){
int iCol = aiCols ? aiCols[j] : pFK->aCol[j].iFrom;
sqlite3ExprCodeGetColumnOfTable(v, pTab, 0, iCol, regRow+j);
sqlite3VdbeAddOp2(v, OP_IsNull, regRow+j, addrOk); VdbeCoverage(v);
}
/* Generate code to query the parent index for a matching parent
** key. If a match is found, jump to addrOk. */
if( pIdx ){
sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, pFK->nCol, regKey,
sqlite3IndexAffinityStr(db,pIdx), pFK->nCol);
sqlite3VdbeAddOp4Int(v, OP_Found, i, addrOk, regKey, 0);
VdbeCoverage(v);
}else if( pParent ){
int jmp = sqlite3VdbeCurrentAddr(v)+2;
sqlite3VdbeAddOp3(v, OP_SeekRowid, i, jmp, regRow); VdbeCoverage(v);
sqlite3VdbeGoto(v, addrOk);
assert( pFK->nCol==1 || db->mallocFailed );
}
/* Generate code to report an FK violation to the caller. */
if( HasRowid(pTab) ){
sqlite3VdbeAddOp2(v, OP_Rowid, 0, regResult+1);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, regResult+1);
}
sqlite3VdbeMultiLoad(v, regResult+2, "siX", pFK->zTo, i-1);
sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, 4);
sqlite3VdbeResolveLabel(v, addrOk);
sqlite3DbFree(db, aiCols);
}
sqlite3VdbeAddOp2(v, OP_Next, 0, addrTop+1); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addrTop);
}
}
break;
#endif /* !defined(SQLITE_OMIT_TRIGGER) */
#endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */
#ifndef SQLITE_OMIT_CASE_SENSITIVE_LIKE_PRAGMA
/* Reinstall the LIKE and GLOB functions. The variant of LIKE
** used will be case sensitive or not depending on the RHS.
*/
case PragTyp_CASE_SENSITIVE_LIKE: {
if( zRight ){
sqlite3RegisterLikeFunctions(db, sqlite3GetBoolean(zRight, 0));
}
}
break;
#endif /* SQLITE_OMIT_CASE_SENSITIVE_LIKE_PRAGMA */
#ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
# define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
#endif
#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/* PRAGMA integrity_check
** PRAGMA integrity_check(N)
** PRAGMA quick_check
** PRAGMA quick_check(N)
**
** Verify the integrity of the database.
**
** The "quick_check" is reduced version of
** integrity_check designed to detect most database corruption
** without the overhead of cross-checking indexes. Quick_check
** is linear time wherease integrity_check is O(NlogN).
**
** The maximum nubmer of errors is 100 by default. A different default
** can be specified using a numeric parameter N.
**
** Or, the parameter N can be the name of a table. In that case, only
** the one table named is verified. The freelist is only verified if
** the named table is "sqlite_schema" (or one of its aliases).
**
** All schemas are checked by default. To check just a single
** schema, use the form:
**
** PRAGMA schema.integrity_check;
*/
case PragTyp_INTEGRITY_CHECK: {
int i, j, addr, mxErr;
Table *pObjTab = 0; /* Check only this one table, if not NULL */
int isQuick = (sqlite3Tolower(zLeft[0])=='q');
/* If the PRAGMA command was of the form "PRAGMA <db>.integrity_check",
** then iDb is set to the index of the database identified by <db>.
** In this case, the integrity of database iDb only is verified by
** the VDBE created below.
**
** Otherwise, if the command was simply "PRAGMA integrity_check" (or
** "PRAGMA quick_check"), then iDb is set to 0. In this case, set iDb
** to -1 here, to indicate that the VDBE should verify the integrity
** of all attached databases. */
assert( iDb>=0 );
assert( iDb==0 || pId2->z );
if( pId2->z==0 ) iDb = -1;
/* Initialize the VDBE program */
pParse->nMem = 6;
/* Set the maximum error count */
mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
if( zRight ){
if( sqlite3GetInt32(zRight, &mxErr) ){
if( mxErr<=0 ){
mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
}
}else{
pObjTab = sqlite3LocateTable(pParse, 0, zRight,
iDb>=0 ? db->aDb[iDb].zDbSName : 0);
}
}
sqlite3VdbeAddOp2(v, OP_Integer, mxErr-1, 1); /* reg[1] holds errors left */
/* Do an integrity check on each database file */
for(i=0; i<db->nDb; i++){
HashElem *x; /* For looping over tables in the schema */
Hash *pTbls; /* Set of all tables in the schema */
int *aRoot; /* Array of root page numbers of all btrees */
int cnt = 0; /* Number of entries in aRoot[] */
int mxIdx = 0; /* Maximum number of indexes for any table */
if( OMIT_TEMPDB && i==1 ) continue;
if( iDb>=0 && i!=iDb ) continue;
sqlite3CodeVerifySchema(pParse, i);
/* Do an integrity check of the B-Tree
**
** Begin by finding the root pages numbers
** for all tables and indices in the database.
*/
assert( sqlite3SchemaMutexHeld(db, i, 0) );
pTbls = &db->aDb[i].pSchema->tblHash;
for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
Table *pTab = sqliteHashData(x); /* Current table */
Index *pIdx; /* An index on pTab */
int nIdx; /* Number of indexes on pTab */
if( pObjTab && pObjTab!=pTab ) continue;
if( HasRowid(pTab) ) cnt++;
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ cnt++; }
if( nIdx>mxIdx ) mxIdx = nIdx;
}
if( cnt==0 ) continue;
if( pObjTab ) cnt++;
aRoot = sqlite3DbMallocRawNN(db, sizeof(int)*(cnt+1));
if( aRoot==0 ) break;
cnt = 0;
if( pObjTab ) aRoot[++cnt] = 0;
for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
Table *pTab = sqliteHashData(x);
Index *pIdx;
if( pObjTab && pObjTab!=pTab ) continue;
if( HasRowid(pTab) ) aRoot[++cnt] = pTab->tnum;
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
aRoot[++cnt] = pIdx->tnum;
}
}
aRoot[0] = cnt;
/* Make sure sufficient number of registers have been allocated */
pParse->nMem = MAX( pParse->nMem, 8+mxIdx );
sqlite3ClearTempRegCache(pParse);
/* Do the b-tree integrity checks */
sqlite3VdbeAddOp4(v, OP_IntegrityCk, 2, cnt, 1, (char*)aRoot,P4_INTARRAY);
sqlite3VdbeChangeP5(v, (u8)i);
addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2); VdbeCoverage(v);
sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zDbSName),
P4_DYNAMIC);
sqlite3VdbeAddOp3(v, OP_Concat, 2, 3, 3);
integrityCheckResultRow(v);
sqlite3VdbeJumpHere(v, addr);
/* Make sure all the indices are constructed correctly.
*/
for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
Table *pTab = sqliteHashData(x);
Index *pIdx, *pPk;
Index *pPrior = 0;
int loopTop;
int iDataCur, iIdxCur;
int r1 = -1;
if( pTab->tnum<1 ) continue; /* Skip VIEWs or VIRTUAL TABLEs */
if( pObjTab && pObjTab!=pTab ) continue;
pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenRead, 0,
1, 0, &iDataCur, &iIdxCur);
/* reg[7] counts the number of entries in the table.
** reg[8+i] counts the number of entries in the i-th index
*/
sqlite3VdbeAddOp2(v, OP_Integer, 0, 7);
for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
sqlite3VdbeAddOp2(v, OP_Integer, 0, 8+j); /* index entries counter */
}
assert( pParse->nMem>=8+j );
assert( sqlite3NoTempsInRange(pParse,1,7+j) );
sqlite3VdbeAddOp2(v, OP_Rewind, iDataCur, 0); VdbeCoverage(v);
loopTop = sqlite3VdbeAddOp2(v, OP_AddImm, 7, 1);
if( !isQuick ){
/* Sanity check on record header decoding */
sqlite3VdbeAddOp3(v, OP_Column, iDataCur, pTab->nNVCol-1,3);
sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
}
/* Verify that all NOT NULL columns really are NOT NULL */
for(j=0; j<pTab->nCol; j++){
char *zErr;
int jmp2;
if( j==pTab->iPKey ) continue;
if( pTab->aCol[j].notNull==0 ) continue;
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, j, 3);
if( sqlite3VdbeGetOp(v,-1)->opcode==OP_Column ){
sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
}
jmp2 = sqlite3VdbeAddOp1(v, OP_NotNull, 3); VdbeCoverage(v);
zErr = sqlite3MPrintf(db, "NULL value in %s.%s", pTab->zName,
pTab->aCol[j].zName);
sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
integrityCheckResultRow(v);
sqlite3VdbeJumpHere(v, jmp2);
}
/* Verify CHECK constraints */
if( pTab->pCheck && (db->flags & SQLITE_IgnoreChecks)==0 ){
ExprList *pCheck = sqlite3ExprListDup(db, pTab->pCheck, 0);
if( db->mallocFailed==0 ){
int addrCkFault = sqlite3VdbeMakeLabel(pParse);
int addrCkOk = sqlite3VdbeMakeLabel(pParse);
char *zErr;
int k;
pParse->iSelfTab = iDataCur + 1;
for(k=pCheck->nExpr-1; k>0; k--){
sqlite3ExprIfFalse(pParse, pCheck->a[k].pExpr, addrCkFault, 0);
}
sqlite3ExprIfTrue(pParse, pCheck->a[0].pExpr, addrCkOk,
SQLITE_JUMPIFNULL);
sqlite3VdbeResolveLabel(v, addrCkFault);
pParse->iSelfTab = 0;
zErr = sqlite3MPrintf(db, "CHECK constraint failed in %s",
pTab->zName);
sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
integrityCheckResultRow(v);
sqlite3VdbeResolveLabel(v, addrCkOk);
}
sqlite3ExprListDelete(db, pCheck);
}
if( !isQuick ){ /* Omit the remaining tests for quick_check */
/* Validate index entries for the current row */
for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
int jmp2, jmp3, jmp4, jmp5;
int ckUniq = sqlite3VdbeMakeLabel(pParse);
if( pPk==pIdx ) continue;
r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 0, &jmp3,
pPrior, r1);
pPrior = pIdx;
sqlite3VdbeAddOp2(v, OP_AddImm, 8+j, 1);/* increment entry count */
/* Verify that an index entry exists for the current table row */
jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, iIdxCur+j, ckUniq, r1,
pIdx->nColumn); VdbeCoverage(v);
sqlite3VdbeLoadString(v, 3, "row ");
sqlite3VdbeAddOp3(v, OP_Concat, 7, 3, 3);
sqlite3VdbeLoadString(v, 4, " missing from index ");
sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
jmp5 = sqlite3VdbeLoadString(v, 4, pIdx->zName);
sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
jmp4 = integrityCheckResultRow(v);
sqlite3VdbeJumpHere(v, jmp2);
/* For UNIQUE indexes, verify that only one entry exists with the
** current key. The entry is unique if (1) any column is NULL
** or (2) the next entry has a different key */
if( IsUniqueIndex(pIdx) ){
int uniqOk = sqlite3VdbeMakeLabel(pParse);
int jmp6;
int kk;
for(kk=0; kk<pIdx->nKeyCol; kk++){
int iCol = pIdx->aiColumn[kk];
assert( iCol!=XN_ROWID && iCol<pTab->nCol );
if( iCol>=0 && pTab->aCol[iCol].notNull ) continue;
sqlite3VdbeAddOp2(v, OP_IsNull, r1+kk, uniqOk);
VdbeCoverage(v);
}
jmp6 = sqlite3VdbeAddOp1(v, OP_Next, iIdxCur+j); VdbeCoverage(v);
sqlite3VdbeGoto(v, uniqOk);
sqlite3VdbeJumpHere(v, jmp6);
sqlite3VdbeAddOp4Int(v, OP_IdxGT, iIdxCur+j, uniqOk, r1,
pIdx->nKeyCol); VdbeCoverage(v);
sqlite3VdbeLoadString(v, 3, "non-unique entry in index ");
sqlite3VdbeGoto(v, jmp5);
sqlite3VdbeResolveLabel(v, uniqOk);
}
sqlite3VdbeJumpHere(v, jmp4);
sqlite3ResolvePartIdxLabel(pParse, jmp3);
}
}
sqlite3VdbeAddOp2(v, OP_Next, iDataCur, loopTop); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, loopTop-1);
if( !isQuick ){
sqlite3VdbeLoadString(v, 2, "wrong # of entries in index ");
for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
if( pPk==pIdx ) continue;
sqlite3VdbeAddOp2(v, OP_Count, iIdxCur+j, 3);
addr = sqlite3VdbeAddOp3(v, OP_Eq, 8+j, 0, 3); VdbeCoverage(v);
sqlite3VdbeChangeP5(v, SQLITE_NOTNULL);
sqlite3VdbeLoadString(v, 4, pIdx->zName);
sqlite3VdbeAddOp3(v, OP_Concat, 4, 2, 3);
integrityCheckResultRow(v);
sqlite3VdbeJumpHere(v, addr);
}
}
}
}
{
static const int iLn = VDBE_OFFSET_LINENO(2);
static const VdbeOpList endCode[] = {
{ OP_AddImm, 1, 0, 0}, /* 0 */
{ OP_IfNotZero, 1, 4, 0}, /* 1 */
{ OP_String8, 0, 3, 0}, /* 2 */
{ OP_ResultRow, 3, 1, 0}, /* 3 */
{ OP_Halt, 0, 0, 0}, /* 4 */
{ OP_String8, 0, 3, 0}, /* 5 */
{ OP_Goto, 0, 3, 0}, /* 6 */
};
VdbeOp *aOp;
aOp = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode, iLn);
if( aOp ){
aOp[0].p2 = 1-mxErr;
aOp[2].p4type = P4_STATIC;
aOp[2].p4.z = "ok";
aOp[5].p4type = P4_STATIC;
aOp[5].p4.z = (char*)sqlite3ErrStr(SQLITE_CORRUPT);
}
sqlite3VdbeChangeP3(v, 0, sqlite3VdbeCurrentAddr(v)-2);
}
}
break;
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */
#ifndef SQLITE_OMIT_UTF16
/*
** PRAGMA encoding
** PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"
**
** In its first form, this pragma returns the encoding of the main
** database. If the database is not initialized, it is initialized now.
**
** The second form of this pragma is a no-op if the main database file
** has not already been initialized. In this case it sets the default
** encoding that will be used for the main database file if a new file
** is created. If an existing main database file is opened, then the
** default text encoding for the existing database is used.
**
** In all cases new databases created using the ATTACH command are
** created to use the same default text encoding as the main database. If
** the main database has not been initialized and/or created when ATTACH
** is executed, this is done before the ATTACH operation.
**
** In the second form this pragma sets the text encoding to be used in
** new database files created using this database handle. It is only
** useful if invoked immediately after the main database i
*/
case PragTyp_ENCODING: {
static const struct EncName {
char *zName;
u8 enc;
} encnames[] = {
{ "UTF8", SQLITE_UTF8 },
{ "UTF-8", SQLITE_UTF8 }, /* Must be element [1] */
{ "UTF-16le", SQLITE_UTF16LE }, /* Must be element [2] */
{ "UTF-16be", SQLITE_UTF16BE }, /* Must be element [3] */
{ "UTF16le", SQLITE_UTF16LE },
{ "UTF16be", SQLITE_UTF16BE },
{ "UTF-16", 0 }, /* SQLITE_UTF16NATIVE */
{ "UTF16", 0 }, /* SQLITE_UTF16NATIVE */
{ 0, 0 }
};
const struct EncName *pEnc;
if( !zRight ){ /* "PRAGMA encoding" */
if( sqlite3ReadSchema(pParse) ) goto pragma_out;
assert( encnames[SQLITE_UTF8].enc==SQLITE_UTF8 );
assert( encnames[SQLITE_UTF16LE].enc==SQLITE_UTF16LE );
assert( encnames[SQLITE_UTF16BE].enc==SQLITE_UTF16BE );
returnSingleText(v, encnames[ENC(pParse->db)].zName);
}else{ /* "PRAGMA encoding = XXX" */
/* Only change the value of sqlite.enc if the database handle is not
** initialized. If the main database exists, the new sqlite.enc value
** will be overwritten when the schema is next loaded. If it does not
** already exists, it will be created to use the new encoding value.
*/
if( (db->mDbFlags & DBFLAG_EncodingFixed)==0 ){
for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){
u8 enc = pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
SCHEMA_ENC(db) = enc;
sqlite3SetTextEncoding(db, enc);
break;
}
}
if( !pEnc->zName ){
sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);
}
}
}
}
break;
#endif /* SQLITE_OMIT_UTF16 */
#ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS
/*
** PRAGMA [schema.]schema_version
** PRAGMA [schema.]schema_version = <integer>
**
** PRAGMA [schema.]user_version
** PRAGMA [schema.]user_version = <integer>
**
** PRAGMA [schema.]freelist_count
**
** PRAGMA [schema.]data_version
**
** PRAGMA [schema.]application_id
** PRAGMA [schema.]application_id = <integer>
**
** The pragma's schema_version and user_version are used to set or get
** the value of the schema-version and user-version, respectively. Both
** the schema-version and the user-version are 32-bit signed integers
** stored in the database header.
**
** The schema-cookie is usually only manipulated internally by SQLite. It
** is incremented by SQLite whenever the database schema is modified (by
** creating or dropping a table or index). The schema version is used by
** SQLite each time a query is executed to ensure that the internal cache
** of the schema used when compiling the SQL query matches the schema of
** the database against which the compiled query is actually executed.
** Subverting this mechanism by using "PRAGMA schema_version" to modify
** the schema-version is potentially dangerous and may lead to program
** crashes or database corruption. Use with caution!
**
** The user-version is not used internally by SQLite. It may be used by
** applications for any purpose.
*/
case PragTyp_HEADER_VALUE: {
int iCookie = pPragma->iArg; /* Which cookie to read or write */
sqlite3VdbeUsesBtree(v, iDb);
if( zRight && (pPragma->mPragFlg & PragFlg_ReadOnly)==0 ){
/* Write the specified cookie value */
static const VdbeOpList setCookie[] = {
{ OP_Transaction, 0, 1, 0}, /* 0 */
{ OP_SetCookie, 0, 0, 0}, /* 1 */
};
VdbeOp *aOp;
sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setCookie));
aOp = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0);
if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
aOp[0].p1 = iDb;
aOp[1].p1 = iDb;
aOp[1].p2 = iCookie;
aOp[1].p3 = sqlite3Atoi(zRight);
aOp[1].p5 = 1;
}else{
/* Read the specified cookie value */
static const VdbeOpList readCookie[] = {
{ OP_Transaction, 0, 0, 0}, /* 0 */
{ OP_ReadCookie, 0, 1, 0}, /* 1 */
{ OP_ResultRow, 1, 1, 0}
};
VdbeOp *aOp;
sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(readCookie));
aOp = sqlite3VdbeAddOpList(v, ArraySize(readCookie),readCookie,0);
if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
aOp[0].p1 = iDb;
aOp[1].p1 = iDb;
aOp[1].p3 = iCookie;
sqlite3VdbeReusable(v);
}
}
break;
#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
/*
** PRAGMA compile_options
**
** Return the names of all compile-time options used in this build,
** one option per row.
*/
case PragTyp_COMPILE_OPTIONS: {
int i = 0;
const char *zOpt;
pParse->nMem = 1;
while( (zOpt = sqlite3_compileoption_get(i++))!=0 ){
sqlite3VdbeLoadString(v, 1, zOpt);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1);
}
sqlite3VdbeReusable(v);
}
break;
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */
#ifndef SQLITE_OMIT_WAL
/*
** PRAGMA [schema.]wal_checkpoint = passive|full|restart|truncate
**
** Checkpoint the database.
*/
case PragTyp_WAL_CHECKPOINT: {
int iBt = (pId2->z?iDb:SQLITE_MAX_ATTACHED);
int eMode = SQLITE_CHECKPOINT_PASSIVE;
if( zRight ){
if( sqlite3StrICmp(zRight, "full")==0 ){
eMode = SQLITE_CHECKPOINT_FULL;
}else if( sqlite3StrICmp(zRight, "restart")==0 ){
eMode = SQLITE_CHECKPOINT_RESTART;
}else if( sqlite3StrICmp(zRight, "truncate")==0 ){
eMode = SQLITE_CHECKPOINT_TRUNCATE;
}
}
pParse->nMem = 3;
sqlite3VdbeAddOp3(v, OP_Checkpoint, iBt, eMode, 1);
sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3);
}
break;
/*
** PRAGMA wal_autocheckpoint
** PRAGMA wal_autocheckpoint = N
**
** Configure a database connection to automatically checkpoint a database
** after accumulating N frames in the log. Or query for the current value
** of N.
*/
case PragTyp_WAL_AUTOCHECKPOINT: {
if( zRight ){
sqlite3_wal_autocheckpoint(db, sqlite3Atoi(zRight));
}
returnSingleInt(v,
db->xWalCallback==sqlite3WalDefaultHook ?
SQLITE_PTR_TO_INT(db->pWalArg) : 0);
}
break;
#endif
/*
** PRAGMA shrink_memory
**
** IMPLEMENTATION-OF: R-23445-46109 This pragma causes the database
** connection on which it is invoked to free up as much memory as it
** can, by calling sqlite3_db_release_memory().
*/
case PragTyp_SHRINK_MEMORY: {
sqlite3_db_release_memory(db);
break;
}
/*
** PRAGMA optimize
** PRAGMA optimize(MASK)
** PRAGMA schema.optimize
** PRAGMA schema.optimize(MASK)
**
** Attempt to optimize the database. All schemas are optimized in the first
** two forms, and only the specified schema is optimized in the latter two.
**
** The details of optimizations performed by this pragma are expected
** to change and improve over time. Applications should anticipate that
** this pragma will perform new optimizations in future releases.
**
** The optional argument is a bitmask of optimizations to perform:
**
** 0x0001 Debugging mode. Do not actually perform any optimizations
** but instead return one line of text for each optimization
** that would have been done. Off by default.
**
** 0x0002 Run ANALYZE on tables that might benefit. On by default.
** See below for additional information.
**
** 0x0004 (Not yet implemented) Record usage and performance
** information from the current session in the
** database file so that it will be available to "optimize"
** pragmas run by future database connections.
**
** 0x0008 (Not yet implemented) Create indexes that might have
** been helpful to recent queries
**
** The default MASK is and always shall be 0xfffe. 0xfffe means perform all
** of the optimizations listed above except Debug Mode, including new
** optimizations that have not yet been invented. If new optimizations are
** ever added that should be off by default, those off-by-default
** optimizations will have bitmasks of 0x10000 or larger.
**
** DETERMINATION OF WHEN TO RUN ANALYZE
**
** In the current implementation, a table is analyzed if only if all of
** the following are true:
**
** (1) MASK bit 0x02 is set.
**
** (2) The query planner used sqlite_stat1-style statistics for one or
** more indexes of the table at some point during the lifetime of
** the current connection.
**
** (3) One or more indexes of the table are currently unanalyzed OR
** the number of rows in the table has increased by 25 times or more
** since the last time ANALYZE was run.
**
** The rules for when tables are analyzed are likely to change in
** future releases.
*/
case PragTyp_OPTIMIZE: {
int iDbLast; /* Loop termination point for the schema loop */
int iTabCur; /* Cursor for a table whose size needs checking */
HashElem *k; /* Loop over tables of a schema */
Schema *pSchema; /* The current schema */
Table *pTab; /* A table in the schema */
Index *pIdx; /* An index of the table */
LogEst szThreshold; /* Size threshold above which reanalysis is needd */
char *zSubSql; /* SQL statement for the OP_SqlExec opcode */
u32 opMask; /* Mask of operations to perform */
if( zRight ){
opMask = (u32)sqlite3Atoi(zRight);
if( (opMask & 0x02)==0 ) break;
}else{
opMask = 0xfffe;
}
iTabCur = pParse->nTab++;
for(iDbLast = zDb?iDb:db->nDb-1; iDb<=iDbLast; iDb++){
if( iDb==1 ) continue;
sqlite3CodeVerifySchema(pParse, iDb);
pSchema = db->aDb[iDb].pSchema;
for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){
pTab = (Table*)sqliteHashData(k);
/* If table pTab has not been used in a way that would benefit from
** having analysis statistics during the current session, then skip it.
** This also has the effect of skipping virtual tables and views */
if( (pTab->tabFlags & TF_StatsUsed)==0 ) continue;
/* Reanalyze if the table is 25 times larger than the last analysis */
szThreshold = pTab->nRowLogEst + 46; assert( sqlite3LogEst(25)==46 );
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( !pIdx->hasStat1 ){
szThreshold = 0; /* Always analyze if any index lacks statistics */
break;
}
}
if( szThreshold ){
sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead);
sqlite3VdbeAddOp3(v, OP_IfSmaller, iTabCur,
sqlite3VdbeCurrentAddr(v)+2+(opMask&1), szThreshold);
VdbeCoverage(v);
}
zSubSql = sqlite3MPrintf(db, "ANALYZE \"%w\".\"%w\"",
db->aDb[iDb].zDbSName, pTab->zName);
if( opMask & 0x01 ){
int r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp4(v, OP_String8, 0, r1, 0, zSubSql, P4_DYNAMIC);
sqlite3VdbeAddOp2(v, OP_ResultRow, r1, 1);
}else{
sqlite3VdbeAddOp4(v, OP_SqlExec, 0, 0, 0, zSubSql, P4_DYNAMIC);
}
}
}
sqlite3VdbeAddOp0(v, OP_Expire);
break;
}
/*
** PRAGMA busy_timeout
** PRAGMA busy_timeout = N
**
** Call sqlite3_busy_timeout(db, N). Return the current timeout value
** if one is set. If no busy handler or a different busy handler is set
** then 0 is returned. Setting the busy_timeout to 0 or negative
** disables the timeout.
*/
/*case PragTyp_BUSY_TIMEOUT*/ default: {
assert( pPragma->ePragTyp==PragTyp_BUSY_TIMEOUT );
if( zRight ){
sqlite3_busy_timeout(db, sqlite3Atoi(zRight));
}
returnSingleInt(v, db->busyTimeout);
break;
}
/*
** PRAGMA soft_heap_limit
** PRAGMA soft_heap_limit = N
**
** IMPLEMENTATION-OF: R-26343-45930 This pragma invokes the
** sqlite3_soft_heap_limit64() interface with the argument N, if N is
** specified and is a non-negative integer.
** IMPLEMENTATION-OF: R-64451-07163 The soft_heap_limit pragma always
** returns the same integer that would be returned by the
** sqlite3_soft_heap_limit64(-1) C-language function.
*/
case PragTyp_SOFT_HEAP_LIMIT: {
sqlite3_int64 N;
if( zRight && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK ){
sqlite3_soft_heap_limit64(N);
}
returnSingleInt(v, sqlite3_soft_heap_limit64(-1));
break;
}
/*
** PRAGMA hard_heap_limit
** PRAGMA hard_heap_limit = N
**
** Invoke sqlite3_hard_heap_limit64() to query or set the hard heap
** limit. The hard heap limit can be activated or lowered by this
** pragma, but not raised or deactivated. Only the
** sqlite3_hard_heap_limit64() C-language API can raise or deactivate
** the hard heap limit. This allows an application to set a heap limit
** constraint that cannot be relaxed by an untrusted SQL script.
*/
case PragTyp_HARD_HEAP_LIMIT: {
sqlite3_int64 N;
if( zRight && sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK ){
sqlite3_int64 iPrior = sqlite3_hard_heap_limit64(-1);
if( N>0 && (iPrior==0 || iPrior>N) ) sqlite3_hard_heap_limit64(N);
}
returnSingleInt(v, sqlite3_hard_heap_limit64(-1));
break;
}
/*
** PRAGMA threads
** PRAGMA threads = N
**
** Configure the maximum number of worker threads. Return the new
** maximum, which might be less than requested.
*/
case PragTyp_THREADS: {
sqlite3_int64 N;
if( zRight
&& sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK
&& N>=0
){
sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, (int)(N&0x7fffffff));
}
returnSingleInt(v, sqlite3_limit(db, SQLITE_LIMIT_WORKER_THREADS, -1));
break;
}
/*
** PRAGMA analysis_limit
** PRAGMA analysis_limit = N
**
** Configure the maximum number of rows that ANALYZE will examine
** in each index that it looks at. Return the new limit.
*/
case PragTyp_ANALYSIS_LIMIT: {
sqlite3_int64 N;
if( zRight
&& sqlite3DecOrHexToI64(zRight, &N)==SQLITE_OK
&& N>=0
){
db->nAnalysisLimit = (int)(N&0x7fffffff);
}
returnSingleInt(v, db->nAnalysisLimit);
break;
}
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
/*
** Report the current state of file logs for all databases
*/
case PragTyp_LOCK_STATUS: {
static const char *const azLockName[] = {
"unlocked", "shared", "reserved", "pending", "exclusive"
};
int i;
pParse->nMem = 2;
for(i=0; i<db->nDb; i++){
Btree *pBt;
const char *zState = "unknown";
int j;
if( db->aDb[i].zDbSName==0 ) continue;
pBt = db->aDb[i].pBt;
if( pBt==0 || sqlite3BtreePager(pBt)==0 ){
zState = "closed";
}else if( sqlite3_file_control(db, i ? db->aDb[i].zDbSName : 0,
SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
zState = azLockName[j];
}
sqlite3VdbeMultiLoad(v, 1, "ss", db->aDb[i].zDbSName, zState);
}
break;
}
#endif
#if defined(SQLITE_ENABLE_CEROD)
case PragTyp_ACTIVATE_EXTENSIONS: if( zRight ){
if( sqlite3StrNICmp(zRight, "cerod-", 6)==0 ){
sqlite3_activate_cerod(&zRight[6]);
}
}
break;
#endif
} /* End of the PRAGMA switch */
/* The following block is a no-op unless SQLITE_DEBUG is defined. Its only
** purpose is to execute assert() statements to verify that if the
** PragFlg_NoColumns1 flag is set and the caller specified an argument
** to the PRAGMA, the implementation has not added any OP_ResultRow
** instructions to the VM. */
if( (pPragma->mPragFlg & PragFlg_NoColumns1) && zRight ){
sqlite3VdbeVerifyNoResultRow(v);
}
pragma_out:
sqlite3DbFree(db, zLeft);
sqlite3DbFree(db, zRight);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*****************************************************************************
** Implementation of an eponymous virtual table that runs a pragma.
**
*/
typedef struct PragmaVtab PragmaVtab;
typedef struct PragmaVtabCursor PragmaVtabCursor;
struct PragmaVtab {
sqlite3_vtab base; /* Base class. Must be first */
sqlite3 *db; /* The database connection to which it belongs */
const PragmaName *pName; /* Name of the pragma */
u8 nHidden; /* Number of hidden columns */
u8 iHidden; /* Index of the first hidden column */
};
struct PragmaVtabCursor {
sqlite3_vtab_cursor base; /* Base class. Must be first */
sqlite3_stmt *pPragma; /* The pragma statement to run */
sqlite_int64 iRowid; /* Current rowid */
char *azArg[2]; /* Value of the argument and schema */
};
/*
** Pragma virtual table module xConnect method.
*/
static int pragmaVtabConnect(
sqlite3 *db,
void *pAux,
int argc, const char *const*argv,
sqlite3_vtab **ppVtab,
char **pzErr
){
const PragmaName *pPragma = (const PragmaName*)pAux;
PragmaVtab *pTab = 0;
int rc;
int i, j;
char cSep = '(';
StrAccum acc;
char zBuf[200];
UNUSED_PARAMETER(argc);
UNUSED_PARAMETER(argv);
sqlite3StrAccumInit(&acc, 0, zBuf, sizeof(zBuf), 0);
sqlite3_str_appendall(&acc, "CREATE TABLE x");
for(i=0, j=pPragma->iPragCName; i<pPragma->nPragCName; i++, j++){
sqlite3_str_appendf(&acc, "%c\"%s\"", cSep, pragCName[j]);
cSep = ',';
}
if( i==0 ){
sqlite3_str_appendf(&acc, "(\"%s\"", pPragma->zName);
i++;
}
j = 0;
if( pPragma->mPragFlg & PragFlg_Result1 ){
sqlite3_str_appendall(&acc, ",arg HIDDEN");
j++;
}
if( pPragma->mPragFlg & (PragFlg_SchemaOpt|PragFlg_SchemaReq) ){
sqlite3_str_appendall(&acc, ",schema HIDDEN");
j++;
}
sqlite3_str_append(&acc, ")", 1);
sqlite3StrAccumFinish(&acc);
assert( strlen(zBuf) < sizeof(zBuf)-1 );
rc = sqlite3_declare_vtab(db, zBuf);
if( rc==SQLITE_OK ){
pTab = (PragmaVtab*)sqlite3_malloc(sizeof(PragmaVtab));
if( pTab==0 ){
rc = SQLITE_NOMEM;
}else{
memset(pTab, 0, sizeof(PragmaVtab));
pTab->pName = pPragma;
pTab->db = db;
pTab->iHidden = i;
pTab->nHidden = j;
}
}else{
*pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
}
*ppVtab = (sqlite3_vtab*)pTab;
return rc;
}
/*
** Pragma virtual table module xDisconnect method.
*/
static int pragmaVtabDisconnect(sqlite3_vtab *pVtab){
PragmaVtab *pTab = (PragmaVtab*)pVtab;
sqlite3_free(pTab);
return SQLITE_OK;
}
/* Figure out the best index to use to search a pragma virtual table.
**
** There are not really any index choices. But we want to encourage the
** query planner to give == constraints on as many hidden parameters as
** possible, and especially on the first hidden parameter. So return a
** high cost if hidden parameters are unconstrained.
*/
static int pragmaVtabBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
PragmaVtab *pTab = (PragmaVtab*)tab;
const struct sqlite3_index_constraint *pConstraint;
int i, j;
int seen[2];
pIdxInfo->estimatedCost = (double)1;
if( pTab->nHidden==0 ){ return SQLITE_OK; }
pConstraint = pIdxInfo->aConstraint;
seen[0] = 0;
seen[1] = 0;
for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
if( pConstraint->usable==0 ) continue;
if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
if( pConstraint->iColumn < pTab->iHidden ) continue;
j = pConstraint->iColumn - pTab->iHidden;
assert( j < 2 );
seen[j] = i+1;
}
if( seen[0]==0 ){
pIdxInfo->estimatedCost = (double)2147483647;
pIdxInfo->estimatedRows = 2147483647;
return SQLITE_OK;
}
j = seen[0]-1;
pIdxInfo->aConstraintUsage[j].argvIndex = 1;
pIdxInfo->aConstraintUsage[j].omit = 1;
if( seen[1]==0 ) return SQLITE_OK;
pIdxInfo->estimatedCost = (double)20;
pIdxInfo->estimatedRows = 20;
j = seen[1]-1;
pIdxInfo->aConstraintUsage[j].argvIndex = 2;
pIdxInfo->aConstraintUsage[j].omit = 1;
return SQLITE_OK;
}
/* Create a new cursor for the pragma virtual table */
static int pragmaVtabOpen(sqlite3_vtab *pVtab, sqlite3_vtab_cursor **ppCursor){
PragmaVtabCursor *pCsr;
pCsr = (PragmaVtabCursor*)sqlite3_malloc(sizeof(*pCsr));
if( pCsr==0 ) return SQLITE_NOMEM;
memset(pCsr, 0, sizeof(PragmaVtabCursor));
pCsr->base.pVtab = pVtab;
*ppCursor = &pCsr->base;
return SQLITE_OK;
}
/* Clear all content from pragma virtual table cursor. */
static void pragmaVtabCursorClear(PragmaVtabCursor *pCsr){
int i;
sqlite3_finalize(pCsr->pPragma);
pCsr->pPragma = 0;
for(i=0; i<ArraySize(pCsr->azArg); i++){
sqlite3_free(pCsr->azArg[i]);
pCsr->azArg[i] = 0;
}
}
/* Close a pragma virtual table cursor */
static int pragmaVtabClose(sqlite3_vtab_cursor *cur){
PragmaVtabCursor *pCsr = (PragmaVtabCursor*)cur;
pragmaVtabCursorClear(pCsr);
sqlite3_free(pCsr);
return SQLITE_OK;
}
/* Advance the pragma virtual table cursor to the next row */
static int pragmaVtabNext(sqlite3_vtab_cursor *pVtabCursor){
PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
int rc = SQLITE_OK;
/* Increment the xRowid value */
pCsr->iRowid++;
assert( pCsr->pPragma );
if( SQLITE_ROW!=sqlite3_step(pCsr->pPragma) ){
rc = sqlite3_finalize(pCsr->pPragma);
pCsr->pPragma = 0;
pragmaVtabCursorClear(pCsr);
}
return rc;
}
/*
** Pragma virtual table module xFilter method.
*/
static int pragmaVtabFilter(
sqlite3_vtab_cursor *pVtabCursor,
int idxNum, const char *idxStr,
int argc, sqlite3_value **argv
){
PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
PragmaVtab *pTab = (PragmaVtab*)(pVtabCursor->pVtab);
int rc;
int i, j;
StrAccum acc;
char *zSql;
UNUSED_PARAMETER(idxNum);
UNUSED_PARAMETER(idxStr);
pragmaVtabCursorClear(pCsr);
j = (pTab->pName->mPragFlg & PragFlg_Result1)!=0 ? 0 : 1;
for(i=0; i<argc; i++, j++){
const char *zText = (const char*)sqlite3_value_text(argv[i]);
assert( j<ArraySize(pCsr->azArg) );
assert( pCsr->azArg[j]==0 );
if( zText ){
pCsr->azArg[j] = sqlite3_mprintf("%s", zText);
if( pCsr->azArg[j]==0 ){
return SQLITE_NOMEM;
}
}
}
sqlite3StrAccumInit(&acc, 0, 0, 0, pTab->db->aLimit[SQLITE_LIMIT_SQL_LENGTH]);
sqlite3_str_appendall(&acc, "PRAGMA ");
if( pCsr->azArg[1] ){
sqlite3_str_appendf(&acc, "%Q.", pCsr->azArg[1]);
}
sqlite3_str_appendall(&acc, pTab->pName->zName);
if( pCsr->azArg[0] ){
sqlite3_str_appendf(&acc, "=%Q", pCsr->azArg[0]);
}
zSql = sqlite3StrAccumFinish(&acc);
if( zSql==0 ) return SQLITE_NOMEM;
rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pPragma, 0);
sqlite3_free(zSql);
if( rc!=SQLITE_OK ){
pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
return rc;
}
return pragmaVtabNext(pVtabCursor);
}
/*
** Pragma virtual table module xEof method.
*/
static int pragmaVtabEof(sqlite3_vtab_cursor *pVtabCursor){
PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
return (pCsr->pPragma==0);
}
/* The xColumn method simply returns the corresponding column from
** the PRAGMA.
*/
static int pragmaVtabColumn(
sqlite3_vtab_cursor *pVtabCursor,
sqlite3_context *ctx,
int i
){
PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
PragmaVtab *pTab = (PragmaVtab*)(pVtabCursor->pVtab);
if( i<pTab->iHidden ){
sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pPragma, i));
}else{
sqlite3_result_text(ctx, pCsr->azArg[i-pTab->iHidden],-1,SQLITE_TRANSIENT);
}
return SQLITE_OK;
}
/*
** Pragma virtual table module xRowid method.
*/
static int pragmaVtabRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *p){
PragmaVtabCursor *pCsr = (PragmaVtabCursor*)pVtabCursor;
*p = pCsr->iRowid;
return SQLITE_OK;
}
/* The pragma virtual table object */
static const sqlite3_module pragmaVtabModule = {
0, /* iVersion */
0, /* xCreate - create a table */
pragmaVtabConnect, /* xConnect - connect to an existing table */
pragmaVtabBestIndex, /* xBestIndex - Determine search strategy */
pragmaVtabDisconnect, /* xDisconnect - Disconnect from a table */
0, /* xDestroy - Drop a table */
pragmaVtabOpen, /* xOpen - open a cursor */
pragmaVtabClose, /* xClose - close a cursor */
pragmaVtabFilter, /* xFilter - configure scan constraints */
pragmaVtabNext, /* xNext - advance a cursor */
pragmaVtabEof, /* xEof */
pragmaVtabColumn, /* xColumn - read data */
pragmaVtabRowid, /* xRowid - read data */
0, /* xUpdate - write data */
0, /* xBegin - begin transaction */
0, /* xSync - sync transaction */
0, /* xCommit - commit transaction */
0, /* xRollback - rollback transaction */
0, /* xFindFunction - function overloading */
0, /* xRename - rename the table */
0, /* xSavepoint */
0, /* xRelease */
0, /* xRollbackTo */
0 /* xShadowName */
};
/*
** Check to see if zTabName is really the name of a pragma. If it is,
** then register an eponymous virtual table for that pragma and return
** a pointer to the Module object for the new virtual table.
*/
SQLITE_PRIVATE Module *sqlite3PragmaVtabRegister(sqlite3 *db, const char *zName){
const PragmaName *pName;
assert( sqlite3_strnicmp(zName, "pragma_", 7)==0 );
pName = pragmaLocate(zName+7);
if( pName==0 ) return 0;
if( (pName->mPragFlg & (PragFlg_Result0|PragFlg_Result1))==0 ) return 0;
assert( sqlite3HashFind(&db->aModule, zName)==0 );
return sqlite3VtabCreateModule(db, zName, &pragmaVtabModule, (void*)pName, 0);
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
#endif /* SQLITE_OMIT_PRAGMA */
/************** End of pragma.c **********************************************/
/************** Begin file prepare.c *****************************************/
/*
** 2005 May 25
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
*/
/* #include "sqliteInt.h" */
/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
*/
static void corruptSchema(
InitData *pData, /* Initialization context */
const char *zObj, /* Object being parsed at the point of error */
const char *zExtra /* Error information */
){
sqlite3 *db = pData->db;
if( db->mallocFailed ){
pData->rc = SQLITE_NOMEM_BKPT;
}else if( pData->pzErrMsg[0]!=0 ){
/* A error message has already been generated. Do not overwrite it */
}else if( pData->mInitFlags & INITFLAG_AlterTable ){
*pData->pzErrMsg = sqlite3DbStrDup(db, zExtra);
pData->rc = SQLITE_ERROR;
}else if( db->flags & SQLITE_WriteSchema ){
pData->rc = SQLITE_CORRUPT_BKPT;
}else{
char *z;
if( zObj==0 ) zObj = "?";
z = sqlite3MPrintf(db, "malformed database schema (%s)", zObj);
if( zExtra && zExtra[0] ) z = sqlite3MPrintf(db, "%z - %s", z, zExtra);
*pData->pzErrMsg = z;
pData->rc = SQLITE_CORRUPT_BKPT;
}
}
/*
** Check to see if any sibling index (another index on the same table)
** of pIndex has the same root page number, and if it does, return true.
** This would indicate a corrupt schema.
*/
SQLITE_PRIVATE int sqlite3IndexHasDuplicateRootPage(Index *pIndex){
Index *p;
for(p=pIndex->pTable->pIndex; p; p=p->pNext){
if( p->tnum==pIndex->tnum && p!=pIndex ) return 1;
}
return 0;
}
/* forward declaration */
static int sqlite3Prepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
u32 prepFlags, /* Zero or more SQLITE_PREPARE_* flags */
Vdbe *pReprepare, /* VM being reprepared */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
);
/*
** This is the callback routine for the code that initializes the
** database. See sqlite3Init() below for additional information.
** This routine is also called from the OP_ParseSchema opcode of the VDBE.
**
** Each callback contains the following information:
**
** argv[0] = type of object: "table", "index", "trigger", or "view".
** argv[1] = name of thing being created
** argv[2] = associated table if an index or trigger
** argv[3] = root page number for table or index. 0 for trigger or view.
** argv[4] = SQL text for the CREATE statement.
**
*/
SQLITE_PRIVATE int sqlite3InitCallback(void *pInit, int argc, char **argv, char **NotUsed){
InitData *pData = (InitData*)pInit;
sqlite3 *db = pData->db;
int iDb = pData->iDb;
assert( argc==5 );
UNUSED_PARAMETER2(NotUsed, argc);
assert( sqlite3_mutex_held(db->mutex) );
db->mDbFlags |= DBFLAG_EncodingFixed;
pData->nInitRow++;
if( db->mallocFailed ){
corruptSchema(pData, argv[1], 0);
return 1;
}
assert( iDb>=0 && iDb<db->nDb );
if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */
if( argv[3]==0 ){
corruptSchema(pData, argv[1], 0);
}else if( sqlite3_strnicmp(argv[4],"create ",7)==0 ){
/* Call the parser to process a CREATE TABLE, INDEX or VIEW.
** But because db->init.busy is set to 1, no VDBE code is generated
** or executed. All the parser does is build the internal data
** structures that describe the table, index, or view.
*/
int rc;
u8 saved_iDb = db->init.iDb;
sqlite3_stmt *pStmt;
TESTONLY(int rcp); /* Return code from sqlite3_prepare() */
assert( db->init.busy );
db->init.iDb = iDb;
if( sqlite3GetUInt32(argv[3], &db->init.newTnum)==0
|| (db->init.newTnum>pData->mxPage && pData->mxPage>0)
){
if( sqlite3Config.bExtraSchemaChecks ){
corruptSchema(pData, argv[1], "invalid rootpage");
}
}
db->init.orphanTrigger = 0;
db->init.azInit = argv;
pStmt = 0;
TESTONLY(rcp = ) sqlite3Prepare(db, argv[4], -1, 0, 0, &pStmt, 0);
rc = db->errCode;
assert( (rc&0xFF)==(rcp&0xFF) );
db->init.iDb = saved_iDb;
/* assert( saved_iDb==0 || (db->mDbFlags & DBFLAG_Vacuum)!=0 ); */
if( SQLITE_OK!=rc ){
if( db->init.orphanTrigger ){
assert( iDb==1 );
}else{
if( rc > pData->rc ) pData->rc = rc;
if( rc==SQLITE_NOMEM ){
sqlite3OomFault(db);
}else if( rc!=SQLITE_INTERRUPT && (rc&0xFF)!=SQLITE_LOCKED ){
corruptSchema(pData, argv[1], sqlite3_errmsg(db));
}
}
}
sqlite3_finalize(pStmt);
}else if( argv[1]==0 || (argv[4]!=0 && argv[4][0]!=0) ){
corruptSchema(pData, argv[1], 0);
}else{
/* If the SQL column is blank it means this is an index that
** was created to be the PRIMARY KEY or to fulfill a UNIQUE
** constraint for a CREATE TABLE. The index should have already
** been created when we processed the CREATE TABLE. All we have
** to do here is record the root page number for that index.
*/
Index *pIndex;
pIndex = sqlite3FindIndex(db, argv[1], db->aDb[iDb].zDbSName);
if( pIndex==0 ){
corruptSchema(pData, argv[1], "orphan index");
}else
if( sqlite3GetUInt32(argv[3],&pIndex->tnum)==0
|| pIndex->tnum<2
|| pIndex->tnum>pData->mxPage
|| sqlite3IndexHasDuplicateRootPage(pIndex)
){
if( sqlite3Config.bExtraSchemaChecks ){
corruptSchema(pData, argv[1], "invalid rootpage");
}
}
}
return 0;
}
/*
** Attempt to read the database schema and initialize internal
** data structures for a single database file. The index of the
** database file is given by iDb. iDb==0 is used for the main
** database. iDb==1 should never be used. iDb>=2 is used for
** auxiliary databases. Return one of the SQLITE_ error codes to
** indicate success or failure.
*/
SQLITE_PRIVATE int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
int rc;
int i;
#ifndef SQLITE_OMIT_DEPRECATED
int size;
#endif
Db *pDb;
char const *azArg[6];
int meta[5];
InitData initData;
const char *zSchemaTabName;
int openedTransaction = 0;
int mask = ((db->mDbFlags & DBFLAG_EncodingFixed) | ~DBFLAG_EncodingFixed);
assert( (db->mDbFlags & DBFLAG_SchemaKnownOk)==0 );
assert( iDb>=0 && iDb<db->nDb );
assert( db->aDb[iDb].pSchema );
assert( sqlite3_mutex_held(db->mutex) );
assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
db->init.busy = 1;
/* Construct the in-memory representation schema tables (sqlite_schema or
** sqlite_temp_schema) by invoking the parser directly. The appropriate
** table name will be inserted automatically by the parser so we can just
** use the abbreviation "x" here. The parser will also automatically tag
** the schema table as read-only. */
azArg[0] = "table";
azArg[1] = zSchemaTabName = SCHEMA_TABLE(iDb);
azArg[2] = azArg[1];
azArg[3] = "1";
azArg[4] = "CREATE TABLE x(type text,name text,tbl_name text,"
"rootpage int,sql text)";
azArg[5] = 0;
initData.db = db;
initData.iDb = iDb;
initData.rc = SQLITE_OK;
initData.pzErrMsg = pzErrMsg;
initData.mInitFlags = mFlags;
initData.nInitRow = 0;
initData.mxPage = 0;
sqlite3InitCallback(&initData, 5, (char **)azArg, 0);
db->mDbFlags &= mask;
if( initData.rc ){
rc = initData.rc;
goto error_out;
}
/* Create a cursor to hold the database open
*/
pDb = &db->aDb[iDb];
if( pDb->pBt==0 ){
assert( iDb==1 );
DbSetProperty(db, 1, DB_SchemaLoaded);
rc = SQLITE_OK;
goto error_out;
}
/* If there is not already a read-only (or read-write) transaction opened
** on the b-tree database, open one now. If a transaction is opened, it
** will be closed before this function returns. */
sqlite3BtreeEnter(pDb->pBt);
if( sqlite3BtreeTxnState(pDb->pBt)==SQLITE_TXN_NONE ){
rc = sqlite3BtreeBeginTrans(pDb->pBt, 0, 0);
if( rc!=SQLITE_OK ){
sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc));
goto initone_error_out;
}
openedTransaction = 1;
}
/* Get the database meta information.
**
** Meta values are as follows:
** meta[0] Schema cookie. Changes with each schema change.
** meta[1] File format of schema layer.
** meta[2] Size of the page cache.
** meta[3] Largest rootpage (auto/incr_vacuum mode)
** meta[4] Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE
** meta[5] User version
** meta[6] Incremental vacuum mode
** meta[7] unused
** meta[8] unused
** meta[9] unused
**
** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to
** the possible values of meta[4].
*/
for(i=0; i<ArraySize(meta); i++){
sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]);
}
if( (db->flags & SQLITE_ResetDatabase)!=0 ){
memset(meta, 0, sizeof(meta));
}
pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1];
/* If opening a non-empty database, check the text encoding. For the
** main database, set sqlite3.enc to the encoding of the main database.
** For an attached db, it is an error if the encoding is not the same
** as sqlite3.enc.
*/
if( meta[BTREE_TEXT_ENCODING-1] ){ /* text encoding */
if( iDb==0 && (db->mDbFlags & DBFLAG_EncodingFixed)==0 ){
u8 encoding;
#ifndef SQLITE_OMIT_UTF16
/* If opening the main database, set ENC(db). */
encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3;
if( encoding==0 ) encoding = SQLITE_UTF8;
#else
encoding = SQLITE_UTF8;
#endif
sqlite3SetTextEncoding(db, encoding);
}else{
/* If opening an attached database, the encoding much match ENC(db) */
if( (meta[BTREE_TEXT_ENCODING-1] & 3)!=ENC(db) ){
sqlite3SetString(pzErrMsg, db, "attached databases must use the same"
" text encoding as main database");
rc = SQLITE_ERROR;
goto initone_error_out;
}
}
}
pDb->pSchema->enc = ENC(db);
if( pDb->pSchema->cache_size==0 ){
#ifndef SQLITE_OMIT_DEPRECATED
size = sqlite3AbsInt32(meta[BTREE_DEFAULT_CACHE_SIZE-1]);
if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }
pDb->pSchema->cache_size = size;
#else
pDb->pSchema->cache_size = SQLITE_DEFAULT_CACHE_SIZE;
#endif
sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
}
/*
** file_format==1 Version 3.0.0.
** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN
** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults
** file_format==4 Version 3.3.0. // DESC indices. Boolean constants
*/
pDb->pSchema->file_format = (u8)meta[BTREE_FILE_FORMAT-1];
if( pDb->pSchema->file_format==0 ){
pDb->pSchema->file_format = 1;
}
if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){
sqlite3SetString(pzErrMsg, db, "unsupported file format");
rc = SQLITE_ERROR;
goto initone_error_out;
}
/* Ticket #2804: When we open a database in the newer file format,
** clear the legacy_file_format pragma flag so that a VACUUM will
** not downgrade the database and thus invalidate any descending
** indices that the user might have created.
*/
if( iDb==0 && meta[BTREE_FILE_FORMAT-1]>=4 ){
db->flags &= ~(u64)SQLITE_LegacyFileFmt;
}
/* Read the schema information out of the schema tables
*/
assert( db->init.busy );
initData.mxPage = sqlite3BtreeLastPage(pDb->pBt);
{
char *zSql;
zSql = sqlite3MPrintf(db,
"SELECT*FROM\"%w\".%s ORDER BY rowid",
db->aDb[iDb].zDbSName, zSchemaTabName);
#ifndef SQLITE_OMIT_AUTHORIZATION
{
sqlite3_xauth xAuth;
xAuth = db->xAuth;
db->xAuth = 0;
#endif
rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
#ifndef SQLITE_OMIT_AUTHORIZATION
db->xAuth = xAuth;
}
#endif
if( rc==SQLITE_OK ) rc = initData.rc;
sqlite3DbFree(db, zSql);
#ifndef SQLITE_OMIT_ANALYZE
if( rc==SQLITE_OK ){
sqlite3AnalysisLoad(db, iDb);
}
#endif
}
if( db->mallocFailed ){
rc = SQLITE_NOMEM_BKPT;
sqlite3ResetAllSchemasOfConnection(db);
}
if( rc==SQLITE_OK || (db->flags&SQLITE_NoSchemaError)){
/* Black magic: If the SQLITE_NoSchemaError flag is set, then consider
** the schema loaded, even if errors occurred. In this situation the
** current sqlite3_prepare() operation will fail, but the following one
** will attempt to compile the supplied statement against whatever subset
** of the schema was loaded before the error occurred. The primary
** purpose of this is to allow access to the sqlite_schema table
** even when its contents have been corrupted.
*/
DbSetProperty(db, iDb, DB_SchemaLoaded);
rc = SQLITE_OK;
}
/* Jump here for an error that occurs after successfully allocating
** curMain and calling sqlite3BtreeEnter(). For an error that occurs
** before that point, jump to error_out.
*/
initone_error_out:
if( openedTransaction ){
sqlite3BtreeCommit(pDb->pBt);
}
sqlite3BtreeLeave(pDb->pBt);
error_out:
if( rc ){
if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
sqlite3OomFault(db);
}
sqlite3ResetOneSchema(db, iDb);
}
db->init.busy = 0;
return rc;
}
/*
** Initialize all database files - the main database file, the file
** used to store temporary tables, and any additional database files
** created using ATTACH statements. Return a success code. If an
** error occurs, write an error message into *pzErrMsg.
**
** After a database is initialized, the DB_SchemaLoaded bit is set
** bit is set in the flags field of the Db structure.
*/
SQLITE_PRIVATE int sqlite3Init(sqlite3 *db, char **pzErrMsg){
int i, rc;
int commit_internal = !(db->mDbFlags&DBFLAG_SchemaChange);
assert( sqlite3_mutex_held(db->mutex) );
assert( sqlite3BtreeHoldsMutex(db->aDb[0].pBt) );
assert( db->init.busy==0 );
ENC(db) = SCHEMA_ENC(db);
assert( db->nDb>0 );
/* Do the main schema first */
if( !DbHasProperty(db, 0, DB_SchemaLoaded) ){
rc = sqlite3InitOne(db, 0, pzErrMsg, 0);
if( rc ) return rc;
}
/* All other schemas after the main schema. The "temp" schema must be last */
for(i=db->nDb-1; i>0; i--){
assert( i==1 || sqlite3BtreeHoldsMutex(db->aDb[i].pBt) );
if( !DbHasProperty(db, i, DB_SchemaLoaded) ){
rc = sqlite3InitOne(db, i, pzErrMsg, 0);
if( rc ) return rc;
}
}
if( commit_internal ){
sqlite3CommitInternalChanges(db);
}
return SQLITE_OK;
}
/*
** This routine is a no-op if the database schema is already initialized.
** Otherwise, the schema is loaded. An error code is returned.
*/
SQLITE_PRIVATE int sqlite3ReadSchema(Parse *pParse){
int rc = SQLITE_OK;
sqlite3 *db = pParse->db;
assert( sqlite3_mutex_held(db->mutex) );
if( !db->init.busy ){
rc = sqlite3Init(db, &pParse->zErrMsg);
if( rc!=SQLITE_OK ){
pParse->rc = rc;
pParse->nErr++;
}else if( db->noSharedCache ){
db->mDbFlags |= DBFLAG_SchemaKnownOk;
}
}
return rc;
}
/*
** Check schema cookies in all databases. If any cookie is out
** of date set pParse->rc to SQLITE_SCHEMA. If all schema cookies
** make no changes to pParse->rc.
*/
static void schemaIsValid(Parse *pParse){
sqlite3 *db = pParse->db;
int iDb;
int rc;
int cookie;
assert( pParse->checkSchema );
assert( sqlite3_mutex_held(db->mutex) );
for(iDb=0; iDb<db->nDb; iDb++){
int openedTransaction = 0; /* True if a transaction is opened */
Btree *pBt = db->aDb[iDb].pBt; /* Btree database to read cookie from */
if( pBt==0 ) continue;
/* If there is not already a read-only (or read-write) transaction opened
** on the b-tree database, open one now. If a transaction is opened, it
** will be closed immediately after reading the meta-value. */
if( sqlite3BtreeTxnState(pBt)==SQLITE_TXN_NONE ){
rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
sqlite3OomFault(db);
}
if( rc!=SQLITE_OK ) return;
openedTransaction = 1;
}
/* Read the schema cookie from the database. If it does not match the
** value stored as part of the in-memory schema representation,
** set Parse.rc to SQLITE_SCHEMA. */
sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie);
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){
sqlite3ResetOneSchema(db, iDb);
pParse->rc = SQLITE_SCHEMA;
}
/* Close the transaction, if one was opened. */
if( openedTransaction ){
sqlite3BtreeCommit(pBt);
}
}
}
/*
** Convert a schema pointer into the iDb index that indicates
** which database file in db->aDb[] the schema refers to.
**
** If the same database is attached more than once, the first
** attached database is returned.
*/
SQLITE_PRIVATE int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){
int i = -32768;
/* If pSchema is NULL, then return -32768. This happens when code in
** expr.c is trying to resolve a reference to a transient table (i.e. one
** created by a sub-select). In this case the return value of this
** function should never be used.
**
** We return -32768 instead of the more usual -1 simply because using
** -32768 as the incorrect index into db->aDb[] is much
** more likely to cause a segfault than -1 (of course there are assert()
** statements too, but it never hurts to play the odds) and
** -32768 will still fit into a 16-bit signed integer.
*/
assert( sqlite3_mutex_held(db->mutex) );
if( pSchema ){
for(i=0; 1; i++){
assert( i<db->nDb );
if( db->aDb[i].pSchema==pSchema ){
break;
}
}
assert( i>=0 && i<db->nDb );
}
return i;
}
/*
** Deallocate a single AggInfo object
*/
static void agginfoFree(sqlite3 *db, AggInfo *p){
sqlite3DbFree(db, p->aCol);
sqlite3DbFree(db, p->aFunc);
sqlite3DbFree(db, p);
}
/*
** Free all memory allocations in the pParse object
*/
SQLITE_PRIVATE void sqlite3ParserReset(Parse *pParse){
sqlite3 *db = pParse->db;
AggInfo *pThis = pParse->pAggList;
while( pThis ){
AggInfo *pNext = pThis->pNext;
agginfoFree(db, pThis);
pThis = pNext;
}
sqlite3DbFree(db, pParse->aLabel);
sqlite3ExprListDelete(db, pParse->pConstExpr);
if( db ){
assert( db->lookaside.bDisable >= pParse->disableLookaside );
db->lookaside.bDisable -= pParse->disableLookaside;
db->lookaside.sz = db->lookaside.bDisable ? 0 : db->lookaside.szTrue;
}
pParse->disableLookaside = 0;
}
/*
** Compile the UTF-8 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
u32 prepFlags, /* Zero or more SQLITE_PREPARE_* flags */
Vdbe *pReprepare, /* VM being reprepared */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
char *zErrMsg = 0; /* Error message */
int rc = SQLITE_OK; /* Result code */
int i; /* Loop counter */
Parse sParse; /* Parsing context */
memset(&sParse, 0, PARSE_HDR_SZ);
memset(PARSE_TAIL(&sParse), 0, PARSE_TAIL_SZ);
sParse.pReprepare = pReprepare;
assert( ppStmt && *ppStmt==0 );
/* assert( !db->mallocFailed ); // not true with SQLITE_USE_ALLOCA */
assert( sqlite3_mutex_held(db->mutex) );
/* For a long-term use prepared statement avoid the use of
** lookaside memory.
*/
if( prepFlags & SQLITE_PREPARE_PERSISTENT ){
sParse.disableLookaside++;
DisableLookaside;
}
sParse.disableVtab = (prepFlags & SQLITE_PREPARE_NO_VTAB)!=0;
/* Check to verify that it is possible to get a read lock on all
** database schemas. The inability to get a read lock indicates that
** some other database connection is holding a write-lock, which in
** turn means that the other connection has made uncommitted changes
** to the schema.
**
** Were we to proceed and prepare the statement against the uncommitted
** schema changes and if those schema changes are subsequently rolled
** back and different changes are made in their place, then when this
** prepared statement goes to run the schema cookie would fail to detect
** the schema change. Disaster would follow.
**
** This thread is currently holding mutexes on all Btrees (because
** of the sqlite3BtreeEnterAll() in sqlite3LockAndPrepare()) so it
** is not possible for another thread to start a new schema change
** while this routine is running. Hence, we do not need to hold
** locks on the schema, we just need to make sure nobody else is
** holding them.
**
** Note that setting READ_UNCOMMITTED overrides most lock detection,
** but it does *not* override schema lock detection, so this all still
** works even if READ_UNCOMMITTED is set.
*/
if( !db->noSharedCache ){
for(i=0; i<db->nDb; i++) {
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
assert( sqlite3BtreeHoldsMutex(pBt) );
rc = sqlite3BtreeSchemaLocked(pBt);
if( rc ){
const char *zDb = db->aDb[i].zDbSName;
sqlite3ErrorWithMsg(db, rc, "database schema is locked: %s", zDb);
testcase( db->flags & SQLITE_ReadUncommit );
goto end_prepare;
}
}
}
}
sqlite3VtabUnlockList(db);
sParse.db = db;
if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
char *zSqlCopy;
int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
testcase( nBytes==mxLen );
testcase( nBytes==mxLen+1 );
if( nBytes>mxLen ){
sqlite3ErrorWithMsg(db, SQLITE_TOOBIG, "statement too long");
rc = sqlite3ApiExit(db, SQLITE_TOOBIG);
goto end_prepare;
}
zSqlCopy = sqlite3DbStrNDup(db, zSql, nBytes);
if( zSqlCopy ){
sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);
sParse.zTail = &zSql[sParse.zTail-zSqlCopy];
sqlite3DbFree(db, zSqlCopy);
}else{
sParse.zTail = &zSql[nBytes];
}
}else{
sqlite3RunParser(&sParse, zSql, &zErrMsg);
}
assert( 0==sParse.nQueryLoop );
if( sParse.rc==SQLITE_DONE ){
sParse.rc = SQLITE_OK;
}
if( sParse.checkSchema ){
schemaIsValid(&sParse);
}
if( pzTail ){
*pzTail = sParse.zTail;
}
if( db->init.busy==0 ){
sqlite3VdbeSetSql(sParse.pVdbe, zSql, (int)(sParse.zTail-zSql), prepFlags);
}
if( db->mallocFailed ){
sParse.rc = SQLITE_NOMEM_BKPT;
}
rc = sParse.rc;
if( rc!=SQLITE_OK ){
if( sParse.pVdbe ) sqlite3VdbeFinalize(sParse.pVdbe);
assert(!(*ppStmt));
}else{
*ppStmt = (sqlite3_stmt*)sParse.pVdbe;
}
if( zErrMsg ){
sqlite3ErrorWithMsg(db, rc, "%s", zErrMsg);
sqlite3DbFree(db, zErrMsg);
}else{
sqlite3Error(db, rc);
}
/* Delete any TriggerPrg structures allocated while parsing this statement. */
while( sParse.pTriggerPrg ){
TriggerPrg *pT = sParse.pTriggerPrg;
sParse.pTriggerPrg = pT->pNext;
sqlite3DbFree(db, pT);
}
end_prepare:
sqlite3ParserReset(&sParse);
return rc;
}
static int sqlite3LockAndPrepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
u32 prepFlags, /* Zero or more SQLITE_PREPARE_* flags */
Vdbe *pOld, /* VM being reprepared */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
int rc;
int cnt = 0;
#ifdef SQLITE_ENABLE_API_ARMOR
if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
#endif
*ppStmt = 0;
if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
return SQLITE_MISUSE_BKPT;
}
sqlite3_mutex_enter(db->mutex);
sqlite3BtreeEnterAll(db);
do{
/* Make multiple attempts to compile the SQL, until it either succeeds
** or encounters a permanent error. A schema problem after one schema
** reset is considered a permanent error. */
rc = sqlite3Prepare(db, zSql, nBytes, prepFlags, pOld, ppStmt, pzTail);
assert( rc==SQLITE_OK || *ppStmt==0 );
}while( rc==SQLITE_ERROR_RETRY
|| (rc==SQLITE_SCHEMA && (sqlite3ResetOneSchema(db,-1), cnt++)==0) );
sqlite3BtreeLeaveAll(db);
rc = sqlite3ApiExit(db, rc);
assert( (rc&db->errMask)==rc );
db->busyHandler.nBusy = 0;
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** Rerun the compilation of a statement after a schema change.
**
** If the statement is successfully recompiled, return SQLITE_OK. Otherwise,
** if the statement cannot be recompiled because another connection has
** locked the sqlite3_schema table, return SQLITE_LOCKED. If any other error
** occurs, return SQLITE_SCHEMA.
*/
SQLITE_PRIVATE int sqlite3Reprepare(Vdbe *p){
int rc;
sqlite3_stmt *pNew;
const char *zSql;
sqlite3 *db;
u8 prepFlags;
assert( sqlite3_mutex_held(sqlite3VdbeDb(p)->mutex) );
zSql = sqlite3_sql((sqlite3_stmt *)p);
assert( zSql!=0 ); /* Reprepare only called for prepare_v2() statements */
db = sqlite3VdbeDb(p);
assert( sqlite3_mutex_held(db->mutex) );
prepFlags = sqlite3VdbePrepareFlags(p);
rc = sqlite3LockAndPrepare(db, zSql, -1, prepFlags, p, &pNew, 0);
if( rc ){
if( rc==SQLITE_NOMEM ){
sqlite3OomFault(db);
}
assert( pNew==0 );
return rc;
}else{
assert( pNew!=0 );
}
sqlite3VdbeSwap((Vdbe*)pNew, p);
sqlite3TransferBindings(pNew, (sqlite3_stmt*)p);
sqlite3VdbeResetStepResult((Vdbe*)pNew);
sqlite3VdbeFinalize((Vdbe*)pNew);
return SQLITE_OK;
}
/*
** Two versions of the official API. Legacy and new use. In the legacy
** version, the original SQL text is not saved in the prepared statement
** and so if a schema change occurs, SQLITE_SCHEMA is returned by
** sqlite3_step(). In the new version, the original SQL text is retained
** and the statement is automatically recompiled if an schema change
** occurs.
*/
SQLITE_API int SQLITE_APICALL sqlite3_prepare(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
int rc;
rc = sqlite3LockAndPrepare(db,zSql,nBytes,0,0,ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */
return rc;
}
SQLITE_API int SQLITE_APICALL sqlite3_prepare_v2(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
int rc;
/* EVIDENCE-OF: R-37923-12173 The sqlite3_prepare_v2() interface works
** exactly the same as sqlite3_prepare_v3() with a zero prepFlags
** parameter.
**
** Proof in that the 5th parameter to sqlite3LockAndPrepare is 0 */
rc = sqlite3LockAndPrepare(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,0,
ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );
return rc;
}
SQLITE_API int SQLITE_APICALL sqlite3_prepare_v3(
sqlite3 *db, /* Database handle. */
const char *zSql, /* UTF-8 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_* flags */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const char **pzTail /* OUT: End of parsed string */
){
int rc;
/* EVIDENCE-OF: R-56861-42673 sqlite3_prepare_v3() differs from
** sqlite3_prepare_v2() only in having the extra prepFlags parameter,
** which is a bit array consisting of zero or more of the
** SQLITE_PREPARE_* flags.
**
** Proof by comparison to the implementation of sqlite3_prepare_v2()
** directly above. */
rc = sqlite3LockAndPrepare(db,zSql,nBytes,
SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK),
0,ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 );
return rc;
}
#ifndef SQLITE_OMIT_UTF16
/*
** Compile the UTF-16 encoded SQL statement zSql into a statement handle.
*/
static int sqlite3Prepare16(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-16 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
u32 prepFlags, /* Zero or more SQLITE_PREPARE_* flags */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
/* This function currently works by first transforming the UTF-16
** encoded string to UTF-8, then invoking sqlite3_prepare(). The
** tricky bit is figuring out the pointer to return in *pzTail.
*/
char *zSql8;
const char *zTail8 = 0;
int rc = SQLITE_OK;
#ifdef SQLITE_ENABLE_API_ARMOR
if( ppStmt==0 ) return SQLITE_MISUSE_BKPT;
#endif
*ppStmt = 0;
if( !sqlite3SafetyCheckOk(db)||zSql==0 ){
return SQLITE_MISUSE_BKPT;
}
if( nBytes>=0 ){
int sz;
const char *z = (const char*)zSql;
for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){}
nBytes = sz;
}
sqlite3_mutex_enter(db->mutex);
zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE);
if( zSql8 ){
rc = sqlite3LockAndPrepare(db, zSql8, -1, prepFlags, 0, ppStmt, &zTail8);
}
if( zTail8 && pzTail ){
/* If sqlite3_prepare returns a tail pointer, we calculate the
** equivalent pointer into the UTF-16 string by counting the unicode
** characters between zSql8 and zTail8, and then returning a pointer
** the same number of characters into the UTF-16 string.
*/
int chars_parsed = sqlite3Utf8CharLen(zSql8, (int)(zTail8-zSql8));
*pzTail = (u8 *)zSql + sqlite3Utf16ByteLen(zSql, chars_parsed);
}
sqlite3DbFree(db, zSql8);
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** Two versions of the official API. Legacy and new use. In the legacy
** version, the original SQL text is not saved in the prepared statement
** and so if a schema change occurs, SQLITE_SCHEMA is returned by
** sqlite3_step(). In the new version, the original SQL text is retained
** and the statement is automatically recompiled if an schema change
** occurs.
*/
SQLITE_API int SQLITE_APICALL sqlite3_prepare16(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-16 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
int rc;
rc = sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */
return rc;
}
SQLITE_API int SQLITE_APICALL sqlite3_prepare16_v2(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-16 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
int rc;
rc = sqlite3Prepare16(db,zSql,nBytes,SQLITE_PREPARE_SAVESQL,ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */
return rc;
}
SQLITE_API int SQLITE_APICALL sqlite3_prepare16_v3(
sqlite3 *db, /* Database handle. */
const void *zSql, /* UTF-16 encoded SQL statement. */
int nBytes, /* Length of zSql in bytes. */
unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_* flags */
sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */
const void **pzTail /* OUT: End of parsed string */
){
int rc;
rc = sqlite3Prepare16(db,zSql,nBytes,
SQLITE_PREPARE_SAVESQL|(prepFlags&SQLITE_PREPARE_MASK),
ppStmt,pzTail);
assert( rc==SQLITE_OK || ppStmt==0 || *ppStmt==0 ); /* VERIFY: F13021 */
return rc;
}
#endif /* SQLITE_OMIT_UTF16 */
/************** End of prepare.c *********************************************/
/************** Begin file select.c ******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
*/
/* #include "sqliteInt.h" */
/*
** An instance of the following object is used to record information about
** how to process the DISTINCT keyword, to simplify passing that information
** into the selectInnerLoop() routine.
*/
typedef struct DistinctCtx DistinctCtx;
struct DistinctCtx {
u8 isTnct; /* True if the DISTINCT keyword is present */
u8 eTnctType; /* One of the WHERE_DISTINCT_* operators */
int tabTnct; /* Ephemeral table used for DISTINCT processing */
int addrTnct; /* Address of OP_OpenEphemeral opcode for tabTnct */
};
/*
** An instance of the following object is used to record information about
** the ORDER BY (or GROUP BY) clause of query is being coded.
**
** The aDefer[] array is used by the sorter-references optimization. For
** example, assuming there is no index that can be used for the ORDER BY,
** for the query:
**
** SELECT a, bigblob FROM t1 ORDER BY a LIMIT 10;
**
** it may be more efficient to add just the "a" values to the sorter, and
** retrieve the associated "bigblob" values directly from table t1 as the
** 10 smallest "a" values are extracted from the sorter.
**
** When the sorter-reference optimization is used, there is one entry in the
** aDefer[] array for each database table that may be read as values are
** extracted from the sorter.
*/
typedef struct SortCtx SortCtx;
struct SortCtx {
ExprList *pOrderBy; /* The ORDER BY (or GROUP BY clause) */
int nOBSat; /* Number of ORDER BY terms satisfied by indices */
int iECursor; /* Cursor number for the sorter */
int regReturn; /* Register holding block-output return address */
int labelBkOut; /* Start label for the block-output subroutine */
int addrSortIndex; /* Address of the OP_SorterOpen or OP_OpenEphemeral */
int labelDone; /* Jump here when done, ex: LIMIT reached */
int labelOBLopt; /* Jump here when sorter is full */
u8 sortFlags; /* Zero or more SORTFLAG_* bits */
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
u8 nDefer; /* Number of valid entries in aDefer[] */
struct DeferredCsr {
Table *pTab; /* Table definition */
int iCsr; /* Cursor number for table */
int nKey; /* Number of PK columns for table pTab (>=1) */
} aDefer[4];
#endif
struct RowLoadInfo *pDeferredRowLoad; /* Deferred row loading info or NULL */
};
#define SORTFLAG_UseSorter 0x01 /* Use SorterOpen instead of OpenEphemeral */
/*
** Delete all the content of a Select structure. Deallocate the structure
** itself depending on the value of bFree
**
** If bFree==1, call sqlite3DbFree() on the p object.
** If bFree==0, Leave the first Select object unfreed
*/
static void clearSelect(sqlite3 *db, Select *p, int bFree){
while( p ){
Select *pPrior = p->pPrior;
sqlite3ExprListDelete(db, p->pEList);
sqlite3SrcListDelete(db, p->pSrc);
sqlite3ExprDelete(db, p->pWhere);
sqlite3ExprListDelete(db, p->pGroupBy);
sqlite3ExprDelete(db, p->pHaving);
sqlite3ExprListDelete(db, p->pOrderBy);
sqlite3ExprDelete(db, p->pLimit);
#ifndef SQLITE_OMIT_WINDOWFUNC
if( OK_IF_ALWAYS_TRUE(p->pWinDefn) ){
sqlite3WindowListDelete(db, p->pWinDefn);
}
#endif
if( OK_IF_ALWAYS_TRUE(p->pWith) ) sqlite3WithDelete(db, p->pWith);
if( bFree ) sqlite3DbFreeNN(db, p);
p = pPrior;
bFree = 1;
}
}
/*
** Initialize a SelectDest structure.
*/
SQLITE_PRIVATE void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){
pDest->eDest = (u8)eDest;
pDest->iSDParm = iParm;
pDest->iSDParm2 = 0;
pDest->zAffSdst = 0;
pDest->iSdst = 0;
pDest->nSdst = 0;
}
/*
** Allocate a new Select structure and return a pointer to that
** structure.
*/
SQLITE_PRIVATE Select *sqlite3SelectNew(
Parse *pParse, /* Parsing context */
ExprList *pEList, /* which columns to include in the result */
SrcList *pSrc, /* the FROM clause -- which tables to scan */
Expr *pWhere, /* the WHERE clause */
ExprList *pGroupBy, /* the GROUP BY clause */
Expr *pHaving, /* the HAVING clause */
ExprList *pOrderBy, /* the ORDER BY clause */
u32 selFlags, /* Flag parameters, such as SF_Distinct */
Expr *pLimit /* LIMIT value. NULL means not used */
){
Select *pNew, *pAllocated;
Select standin;
pAllocated = pNew = sqlite3DbMallocRawNN(pParse->db, sizeof(*pNew) );
if( pNew==0 ){
assert( pParse->db->mallocFailed );
pNew = &standin;
}
if( pEList==0 ){
pEList = sqlite3ExprListAppend(pParse, 0,
sqlite3Expr(pParse->db,TK_ASTERISK,0));
}
pNew->pEList = pEList;
pNew->op = TK_SELECT;
pNew->selFlags = selFlags;
pNew->iLimit = 0;
pNew->iOffset = 0;
pNew->selId = ++pParse->nSelect;
pNew->addrOpenEphm[0] = -1;
pNew->addrOpenEphm[1] = -1;
pNew->nSelectRow = 0;
if( pSrc==0 ) pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*pSrc));
pNew->pSrc = pSrc;
pNew->pWhere = pWhere;
pNew->pGroupBy = pGroupBy;
pNew->pHaving = pHaving;
pNew->pOrderBy = pOrderBy;
pNew->pPrior = 0;
pNew->pNext = 0;
pNew->pLimit = pLimit;
pNew->pWith = 0;
#ifndef SQLITE_OMIT_WINDOWFUNC
pNew->pWin = 0;
pNew->pWinDefn = 0;
#endif
if( pParse->db->mallocFailed ) {
clearSelect(pParse->db, pNew, pNew!=&standin);
pAllocated = 0;
}else{
assert( pNew->pSrc!=0 || pParse->nErr>0 );
}
return pAllocated;
}
/*
** Delete the given Select structure and all of its substructures.
*/
SQLITE_PRIVATE void sqlite3SelectDelete(sqlite3 *db, Select *p){
if( OK_IF_ALWAYS_TRUE(p) ) clearSelect(db, p, 1);
}
/*
** Return a pointer to the right-most SELECT statement in a compound.
*/
static Select *findRightmost(Select *p){
while( p->pNext ) p = p->pNext;
return p;
}
/*
** Given 1 to 3 identifiers preceding the JOIN keyword, determine the
** type of join. Return an integer constant that expresses that type
** in terms of the following bit values:
**
** JT_INNER
** JT_CROSS
** JT_OUTER
** JT_NATURAL
** JT_LEFT
** JT_RIGHT
**
** A full outer join is the combination of JT_LEFT and JT_RIGHT.
**
** If an illegal or unsupported join type is seen, then still return
** a join type, but put an error in the pParse structure.
*/
SQLITE_PRIVATE int sqlite3JoinType(Parse *pParse, Token *pA, Token *pB, Token *pC){
int jointype = 0;
Token *apAll[3];
Token *p;
/* 0123456789 123456789 123456789 123 */
static const char zKeyText[] = "naturaleftouterightfullinnercross";
static const struct {
u8 i; /* Beginning of keyword text in zKeyText[] */
u8 nChar; /* Length of the keyword in characters */
u8 code; /* Join type mask */
} aKeyword[] = {
/* natural */ { 0, 7, JT_NATURAL },
/* left */ { 6, 4, JT_LEFT|JT_OUTER },
/* outer */ { 10, 5, JT_OUTER },
/* right */ { 14, 5, JT_RIGHT|JT_OUTER },
/* full */ { 19, 4, JT_LEFT|JT_RIGHT|JT_OUTER },
/* inner */ { 23, 5, JT_INNER },
/* cross */ { 28, 5, JT_INNER|JT_CROSS },
};
int i, j;
apAll[0] = pA;
apAll[1] = pB;
apAll[2] = pC;
for(i=0; i<3 && apAll[i]; i++){
p = apAll[i];
for(j=0; j<ArraySize(aKeyword); j++){
if( p->n==aKeyword[j].nChar
&& sqlite3StrNICmp((char*)p->z, &zKeyText[aKeyword[j].i], p->n)==0 ){
jointype |= aKeyword[j].code;
break;
}
}
testcase( j==0 || j==1 || j==2 || j==3 || j==4 || j==5 || j==6 );
if( j>=ArraySize(aKeyword) ){
jointype |= JT_ERROR;
break;
}
}
if(
(jointype & (JT_INNER|JT_OUTER))==(JT_INNER|JT_OUTER) ||
(jointype & JT_ERROR)!=0
){
const char *zSp = " ";
assert( pB!=0 );
if( pC==0 ){ zSp++; }
sqlite3ErrorMsg(pParse, "unknown or unsupported join type: "
"%T %T%s%T", pA, pB, zSp, pC);
jointype = JT_INNER;
}else if( (jointype & JT_OUTER)!=0
&& (jointype & (JT_LEFT|JT_RIGHT))!=JT_LEFT ){
sqlite3ErrorMsg(pParse,
"RIGHT and FULL OUTER JOINs are not currently supported");
jointype = JT_INNER;
}
return jointype;
}
/*
** Return the index of a column in a table. Return -1 if the column
** is not contained in the table.
*/
static int columnIndex(Table *pTab, const char *zCol){
int i;
u8 h = sqlite3StrIHash(zCol);
Column *pCol;
for(pCol=pTab->aCol, i=0; i<pTab->nCol; pCol++, i++){
if( pCol->hName==h && sqlite3StrICmp(pCol->zName, zCol)==0 ) return i;
}
return -1;
}
/*
** Search the first N tables in pSrc, from left to right, looking for a
** table that has a column named zCol.
**
** When found, set *piTab and *piCol to the table index and column index
** of the matching column and return TRUE.
**
** If not found, return FALSE.
*/
static int tableAndColumnIndex(
SrcList *pSrc, /* Array of tables to search */
int N, /* Number of tables in pSrc->a[] to search */
const char *zCol, /* Name of the column we are looking for */
int *piTab, /* Write index of pSrc->a[] here */
int *piCol, /* Write index of pSrc->a[*piTab].pTab->aCol[] here */
int bIgnoreHidden /* True to ignore hidden columns */
){
int i; /* For looping over tables in pSrc */
int iCol; /* Index of column matching zCol */
assert( (piTab==0)==(piCol==0) ); /* Both or neither are NULL */
for(i=0; i<N; i++){
iCol = columnIndex(pSrc->a[i].pTab, zCol);
if( iCol>=0
&& (bIgnoreHidden==0 || IsHiddenColumn(&pSrc->a[i].pTab->aCol[iCol])==0)
){
if( piTab ){
*piTab = i;
*piCol = iCol;
}
return 1;
}
}
return 0;
}
/*
** This function is used to add terms implied by JOIN syntax to the
** WHERE clause expression of a SELECT statement. The new term, which
** is ANDed with the existing WHERE clause, is of the form:
**
** (tab1.col1 = tab2.col2)
**
** where tab1 is the iSrc'th table in SrcList pSrc and tab2 is the
** (iSrc+1)'th. Column col1 is column iColLeft of tab1, and col2 is
** column iColRight of tab2.
*/
static void addWhereTerm(
Parse *pParse, /* Parsing context */
SrcList *pSrc, /* List of tables in FROM clause */
int iLeft, /* Index of first table to join in pSrc */
int iColLeft, /* Index of column in first table */
int iRight, /* Index of second table in pSrc */
int iColRight, /* Index of column in second table */
int isOuterJoin, /* True if this is an OUTER join */
Expr **ppWhere /* IN/OUT: The WHERE clause to add to */
){
sqlite3 *db = pParse->db;
Expr *pE1;
Expr *pE2;
Expr *pEq;
assert( iLeft<iRight );
assert( pSrc->nSrc>iRight );
assert( pSrc->a[iLeft].pTab );
assert( pSrc->a[iRight].pTab );
pE1 = sqlite3CreateColumnExpr(db, pSrc, iLeft, iColLeft);
pE2 = sqlite3CreateColumnExpr(db, pSrc, iRight, iColRight);
pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2);
if( pEq && isOuterJoin ){
ExprSetProperty(pEq, EP_FromJoin);
assert( !ExprHasProperty(pEq, EP_TokenOnly|EP_Reduced) );
ExprSetVVAProperty(pEq, EP_NoReduce);
pEq->iRightJoinTable = (i16)pE2->iTable;
}
*ppWhere = sqlite3ExprAnd(pParse, *ppWhere, pEq);
}
/*
** Set the EP_FromJoin property on all terms of the given expression.
** And set the Expr.iRightJoinTable to iTable for every term in the
** expression.
**
** The EP_FromJoin property is used on terms of an expression to tell
** the LEFT OUTER JOIN processing logic that this term is part of the
** join restriction specified in the ON or USING clause and not a part
** of the more general WHERE clause. These terms are moved over to the
** WHERE clause during join processing but we need to remember that they
** originated in the ON or USING clause.
**
** The Expr.iRightJoinTable tells the WHERE clause processing that the
** expression depends on table iRightJoinTable even if that table is not
** explicitly mentioned in the expression. That information is needed
** for cases like this:
**
** SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.b AND t1.x=5
**
** The where clause needs to defer the handling of the t1.x=5
** term until after the t2 loop of the join. In that way, a
** NULL t2 row will be inserted whenever t1.x!=5. If we do not
** defer the handling of t1.x=5, it will be processed immediately
** after the t1 loop and rows with t1.x!=5 will never appear in
** the output, which is incorrect.
*/
SQLITE_PRIVATE void sqlite3SetJoinExpr(Expr *p, int iTable){
while( p ){
ExprSetProperty(p, EP_FromJoin);
assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) );
ExprSetVVAProperty(p, EP_NoReduce);
p->iRightJoinTable = (i16)iTable;
if( p->op==TK_FUNCTION && p->x.pList ){
int i;
for(i=0; i<p->x.pList->nExpr; i++){
sqlite3SetJoinExpr(p->x.pList->a[i].pExpr, iTable);
}
}
sqlite3SetJoinExpr(p->pLeft, iTable);
p = p->pRight;
}
}
/* Undo the work of sqlite3SetJoinExpr(). In the expression p, convert every
** term that is marked with EP_FromJoin and iRightJoinTable==iTable into
** an ordinary term that omits the EP_FromJoin mark.
**
** This happens when a LEFT JOIN is simplified into an ordinary JOIN.
*/
static void unsetJoinExpr(Expr *p, int iTable){
while( p ){
if( ExprHasProperty(p, EP_FromJoin)
&& (iTable<0 || p->iRightJoinTable==iTable) ){
ExprClearProperty(p, EP_FromJoin);
}
if( p->op==TK_FUNCTION && p->x.pList ){
int i;
for(i=0; i<p->x.pList->nExpr; i++){
unsetJoinExpr(p->x.pList->a[i].pExpr, iTable);
}
}
unsetJoinExpr(p->pLeft, iTable);
p = p->pRight;
}
}
/*
** This routine processes the join information for a SELECT statement.
** ON and USING clauses are converted into extra terms of the WHERE clause.
** NATURAL joins also create extra WHERE clause terms.
**
** The terms of a FROM clause are contained in the Select.pSrc structure.
** The left most table is the first entry in Select.pSrc. The right-most
** table is the last entry. The join operator is held in the entry to
** the left. Thus entry 0 contains the join operator for the join between
** entries 0 and 1. Any ON or USING clauses associated with the join are
** also attached to the left entry.
**
** This routine returns the number of errors encountered.
*/
static int sqliteProcessJoin(Parse *pParse, Select *p){
SrcList *pSrc; /* All tables in the FROM clause */
int i, j; /* Loop counters */
struct SrcList_item *pLeft; /* Left table being joined */
struct SrcList_item *pRight; /* Right table being joined */
pSrc = p->pSrc;
pLeft = &pSrc->a[0];
pRight = &pLeft[1];
for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
Table *pRightTab = pRight->pTab;
int isOuter;
if( NEVER(pLeft->pTab==0 || pRightTab==0) ) continue;
isOuter = (pRight->fg.jointype & JT_OUTER)!=0;
/* When the NATURAL keyword is present, add WHERE clause terms for
** every column that the two tables have in common.
*/
if( pRight->fg.jointype & JT_NATURAL ){
if( pRight->pOn || pRight->pUsing ){
sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
"an ON or USING clause", 0);
return 1;
}
for(j=0; j<pRightTab->nCol; j++){
char *zName; /* Name of column in the right table */
int iLeft; /* Matching left table */
int iLeftCol; /* Matching column in the left table */
if( IsHiddenColumn(&pRightTab->aCol[j]) ) continue;
zName = pRightTab->aCol[j].zName;
if( tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol, 1) ){
addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, j,
isOuter, &p->pWhere);
}
}
}
/* Disallow both ON and USING clauses in the same join
*/
if( pRight->pOn && pRight->pUsing ){
sqlite3ErrorMsg(pParse, "cannot have both ON and USING "
"clauses in the same join");
return 1;
}
/* Add the ON clause to the end of the WHERE clause, connected by
** an AND operator.
*/
if( pRight->pOn ){
if( isOuter ) sqlite3SetJoinExpr(pRight->pOn, pRight->iCursor);
p->pWhere = sqlite3ExprAnd(pParse, p->pWhere, pRight->pOn);
pRight->pOn = 0;
}
/* Create extra terms on the WHERE clause for each column named
** in the USING clause. Example: If the two tables to be joined are
** A and B and the USING clause names X, Y, and Z, then add this
** to the WHERE clause: A.X=B.X AND A.Y=B.Y AND A.Z=B.Z
** Report an error if any column mentioned in the USING clause is
** not contained in both tables to be joined.
*/
if( pRight->pUsing ){
IdList *pList = pRight->pUsing;
for(j=0; j<pList->nId; j++){
char *zName; /* Name of the term in the USING clause */
int iLeft; /* Table on the left with matching column name */
int iLeftCol; /* Column number of matching column on the left */
int iRightCol; /* Column number of matching column on the right */
zName = pList->a[j].zName;
iRightCol = columnIndex(pRightTab, zName);
if( iRightCol<0
|| !tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol, 0)
){
sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
"not present in both tables", zName);
return 1;
}
addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, iRightCol,
isOuter, &p->pWhere);
}
}
}
return 0;
}
/*
** An instance of this object holds information (beyond pParse and pSelect)
** needed to load the next result row that is to be added to the sorter.
*/
typedef struct RowLoadInfo RowLoadInfo;
struct RowLoadInfo {
int regResult; /* Store results in array of registers here */
u8 ecelFlags; /* Flag argument to ExprCodeExprList() */
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
ExprList *pExtra; /* Extra columns needed by sorter refs */
int regExtraResult; /* Where to load the extra columns */
#endif
};
/*
** This routine does the work of loading query data into an array of
** registers so that it can be added to the sorter.
*/
static void innerLoopLoadRow(
Parse *pParse, /* Statement under construction */
Select *pSelect, /* The query being coded */
RowLoadInfo *pInfo /* Info needed to complete the row load */
){
sqlite3ExprCodeExprList(pParse, pSelect->pEList, pInfo->regResult,
0, pInfo->ecelFlags);
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
if( pInfo->pExtra ){
sqlite3ExprCodeExprList(pParse, pInfo->pExtra, pInfo->regExtraResult, 0, 0);
sqlite3ExprListDelete(pParse->db, pInfo->pExtra);
}
#endif
}
/*
** Code the OP_MakeRecord instruction that generates the entry to be
** added into the sorter.
**
** Return the register in which the result is stored.
*/
static int makeSorterRecord(
Parse *pParse,
SortCtx *pSort,
Select *pSelect,
int regBase,
int nBase
){
int nOBSat = pSort->nOBSat;
Vdbe *v = pParse->pVdbe;
int regOut = ++pParse->nMem;
if( pSort->pDeferredRowLoad ){
innerLoopLoadRow(pParse, pSelect, pSort->pDeferredRowLoad);
}
sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nBase-nOBSat, regOut);
return regOut;
}
/*
** Generate code that will push the record in registers regData
** through regData+nData-1 onto the sorter.
*/
static void pushOntoSorter(
Parse *pParse, /* Parser context */
SortCtx *pSort, /* Information about the ORDER BY clause */
Select *pSelect, /* The whole SELECT statement */
int regData, /* First register holding data to be sorted */
int regOrigData, /* First register holding data before packing */
int nData, /* Number of elements in the regData data array */
int nPrefixReg /* No. of reg prior to regData available for use */
){
Vdbe *v = pParse->pVdbe; /* Stmt under construction */
int bSeq = ((pSort->sortFlags & SORTFLAG_UseSorter)==0);
int nExpr = pSort->pOrderBy->nExpr; /* No. of ORDER BY terms */
int nBase = nExpr + bSeq + nData; /* Fields in sorter record */
int regBase; /* Regs for sorter record */
int regRecord = 0; /* Assembled sorter record */
int nOBSat = pSort->nOBSat; /* ORDER BY terms to skip */
int op; /* Opcode to add sorter record to sorter */
int iLimit; /* LIMIT counter */
int iSkip = 0; /* End of the sorter insert loop */
assert( bSeq==0 || bSeq==1 );
/* Three cases:
** (1) The data to be sorted has already been packed into a Record
** by a prior OP_MakeRecord. In this case nData==1 and regData
** will be completely unrelated to regOrigData.
** (2) All output columns are included in the sort record. In that
** case regData==regOrigData.
** (3) Some output columns are omitted from the sort record due to
** the SQLITE_ENABLE_SORTER_REFERENCE optimization, or due to the
** SQLITE_ECEL_OMITREF optimization, or due to the
** SortCtx.pDeferredRowLoad optimiation. In any of these cases
** regOrigData is 0 to prevent this routine from trying to copy
** values that might not yet exist.
*/
assert( nData==1 || regData==regOrigData || regOrigData==0 );
if( nPrefixReg ){
assert( nPrefixReg==nExpr+bSeq );
regBase = regData - nPrefixReg;
}else{
regBase = pParse->nMem + 1;
pParse->nMem += nBase;
}
assert( pSelect->iOffset==0 || pSelect->iLimit!=0 );
iLimit = pSelect->iOffset ? pSelect->iOffset+1 : pSelect->iLimit;
pSort->labelDone = sqlite3VdbeMakeLabel(pParse);
sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, regOrigData,
SQLITE_ECEL_DUP | (regOrigData? SQLITE_ECEL_REF : 0));
if( bSeq ){
sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr);
}
if( nPrefixReg==0 && nData>0 ){
sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+bSeq, nData);
}
if( nOBSat>0 ){
int regPrevKey; /* The first nOBSat columns of the previous row */
int addrFirst; /* Address of the OP_IfNot opcode */
int addrJmp; /* Address of the OP_Jump opcode */
VdbeOp *pOp; /* Opcode that opens the sorter */
int nKey; /* Number of sorting key columns, including OP_Sequence */
KeyInfo *pKI; /* Original KeyInfo on the sorter table */
regRecord = makeSorterRecord(pParse, pSort, pSelect, regBase, nBase);
regPrevKey = pParse->nMem+1;
pParse->nMem += pSort->nOBSat;
nKey = nExpr - pSort->nOBSat + bSeq;
if( bSeq ){
addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr);
}else{
addrFirst = sqlite3VdbeAddOp1(v, OP_SequenceTest, pSort->iECursor);
}
VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat);
pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);
if( pParse->db->mallocFailed ) return;
pOp->p2 = nKey + nData;
pKI = pOp->p4.pKeyInfo;
memset(pKI->aSortFlags, 0, pKI->nKeyField); /* Makes OP_Jump testable */
sqlite3VdbeChangeP4(v, -1, (char*)pKI, P4_KEYINFO);
testcase( pKI->nAllField > pKI->nKeyField+2 );
pOp->p4.pKeyInfo = sqlite3KeyInfoFromExprList(pParse,pSort->pOrderBy,nOBSat,
pKI->nAllField-pKI->nKeyField-1);
pOp = 0; /* Ensure pOp not used after sqltie3VdbeAddOp3() */
addrJmp = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v);
pSort->labelBkOut = sqlite3VdbeMakeLabel(pParse);
pSort->regReturn = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor);
if( iLimit ){
sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, pSort->labelDone);
VdbeCoverage(v);
}
sqlite3VdbeJumpHere(v, addrFirst);
sqlite3ExprCodeMove(pParse, regBase, regPrevKey, pSort->nOBSat);
sqlite3VdbeJumpHere(v, addrJmp);
}
if( iLimit ){
/* At this point the values for the new sorter entry are stored
** in an array of registers. They need to be composed into a record
** and inserted into the sorter if either (a) there are currently
** less than LIMIT+OFFSET items or (b) the new record is smaller than
** the largest record currently in the sorter. If (b) is true and there
** are already LIMIT+OFFSET items in the sorter, delete the largest
** entry before inserting the new one. This way there are never more
** than LIMIT+OFFSET items in the sorter.
**
** If the new record does not need to be inserted into the sorter,
** jump to the next iteration of the loop. If the pSort->labelOBLopt
** value is not zero, then it is a label of where to jump. Otherwise,
** just bypass the row insert logic. See the header comment on the
** sqlite3WhereOrderByLimitOptLabel() function for additional info.
*/
int iCsr = pSort->iECursor;
sqlite3VdbeAddOp2(v, OP_IfNotZero, iLimit, sqlite3VdbeCurrentAddr(v)+4);
VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_Last, iCsr, 0);
iSkip = sqlite3VdbeAddOp4Int(v, OP_IdxLE,
iCsr, 0, regBase+nOBSat, nExpr-nOBSat);
VdbeCoverage(v);
sqlite3VdbeAddOp1(v, OP_Delete, iCsr);
}
if( regRecord==0 ){
regRecord = makeSorterRecord(pParse, pSort, pSelect, regBase, nBase);
}
if( pSort->sortFlags & SORTFLAG_UseSorter ){
op = OP_SorterInsert;
}else{
op = OP_IdxInsert;
}
sqlite3VdbeAddOp4Int(v, op, pSort->iECursor, regRecord,
regBase+nOBSat, nBase-nOBSat);
if( iSkip ){
sqlite3VdbeChangeP2(v, iSkip,
pSort->labelOBLopt ? pSort->labelOBLopt : sqlite3VdbeCurrentAddr(v));
}
}
/*
** Add code to implement the OFFSET
*/
static void codeOffset(
Vdbe *v, /* Generate code into this VM */
int iOffset, /* Register holding the offset counter */
int iContinue /* Jump here to skip the current record */
){
if( iOffset>0 ){
sqlite3VdbeAddOp3(v, OP_IfPos, iOffset, iContinue, 1); VdbeCoverage(v);
VdbeComment((v, "OFFSET"));
}
}
/*
** Add code that will check to make sure the N registers starting at iMem
** form a distinct entry. iTab is a sorting index that holds previously
** seen combinations of the N values. A new entry is made in iTab
** if the current N values are new.
**
** A jump to addrRepeat is made and the N+1 values are popped from the
** stack if the top N elements are not distinct.
*/
static void codeDistinct(
Parse *pParse, /* Parsing and code generating context */
int iTab, /* A sorting index used to test for distinctness */
int addrRepeat, /* Jump to here if not distinct */
int N, /* Number of elements */
int iMem /* First element */
){
Vdbe *v;
int r1;
v = pParse->pVdbe;
r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N); VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iTab, r1, iMem, N);
sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
sqlite3ReleaseTempReg(pParse, r1);
}
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
/*
** This function is called as part of inner-loop generation for a SELECT
** statement with an ORDER BY that is not optimized by an index. It
** determines the expressions, if any, that the sorter-reference
** optimization should be used for. The sorter-reference optimization
** is used for SELECT queries like:
**
** SELECT a, bigblob FROM t1 ORDER BY a LIMIT 10
**
** If the optimization is used for expression "bigblob", then instead of
** storing values read from that column in the sorter records, the PK of
** the row from table t1 is stored instead. Then, as records are extracted from
** the sorter to return to the user, the required value of bigblob is
** retrieved directly from table t1. If the values are very large, this
** can be more efficient than storing them directly in the sorter records.
**
** The ExprList_item.bSorterRef flag is set for each expression in pEList
** for which the sorter-reference optimization should be enabled.
** Additionally, the pSort->aDefer[] array is populated with entries
** for all cursors required to evaluate all selected expressions. Finally.
** output variable (*ppExtra) is set to an expression list containing
** expressions for all extra PK values that should be stored in the
** sorter records.
*/
static void selectExprDefer(
Parse *pParse, /* Leave any error here */
SortCtx *pSort, /* Sorter context */
ExprList *pEList, /* Expressions destined for sorter */
ExprList **ppExtra /* Expressions to append to sorter record */
){
int i;
int nDefer = 0;
ExprList *pExtra = 0;
for(i=0; i<pEList->nExpr; i++){
struct ExprList_item *pItem = &pEList->a[i];
if( pItem->u.x.iOrderByCol==0 ){
Expr *pExpr = pItem->pExpr;
Table *pTab = pExpr->y.pTab;
if( pExpr->op==TK_COLUMN && pExpr->iColumn>=0 && pTab && !IsVirtual(pTab)
&& (pTab->aCol[pExpr->iColumn].colFlags & COLFLAG_SORTERREF)
){
int j;
for(j=0; j<nDefer; j++){
if( pSort->aDefer[j].iCsr==pExpr->iTable ) break;
}
if( j==nDefer ){
if( nDefer==ArraySize(pSort->aDefer) ){
continue;
}else{
int nKey = 1;
int k;
Index *pPk = 0;
if( !HasRowid(pTab) ){
pPk = sqlite3PrimaryKeyIndex(pTab);
nKey = pPk->nKeyCol;
}
for(k=0; k<nKey; k++){
Expr *pNew = sqlite3PExpr(pParse, TK_COLUMN, 0, 0);
if( pNew ){
pNew->iTable = pExpr->iTable;
pNew->y.pTab = pExpr->y.pTab;
pNew->iColumn = pPk ? pPk->aiColumn[k] : -1;
pExtra = sqlite3ExprListAppend(pParse, pExtra, pNew);
}
}
pSort->aDefer[nDefer].pTab = pExpr->y.pTab;
pSort->aDefer[nDefer].iCsr = pExpr->iTable;
pSort->aDefer[nDefer].nKey = nKey;
nDefer++;
}
}
pItem->bSorterRef = 1;
}
}
}
pSort->nDefer = (u8)nDefer;
*ppExtra = pExtra;
}
#endif
/*
** This routine generates the code for the inside of the inner loop
** of a SELECT.
**
** If srcTab is negative, then the p->pEList expressions
** are evaluated in order to get the data for this row. If srcTab is
** zero or more, then data is pulled from srcTab and p->pEList is used only
** to get the number of columns and the collation sequence for each column.
*/
static void selectInnerLoop(
Parse *pParse, /* The parser context */
Select *p, /* The complete select statement being coded */
int srcTab, /* Pull data from this table if non-negative */
SortCtx *pSort, /* If not NULL, info on how to process ORDER BY */
DistinctCtx *pDistinct, /* If not NULL, info on how to process DISTINCT */
SelectDest *pDest, /* How to dispose of the results */
int iContinue, /* Jump here to continue with next row */
int iBreak /* Jump here to break out of the inner loop */
){
Vdbe *v = pParse->pVdbe;
int i;
int hasDistinct; /* True if the DISTINCT keyword is present */
int eDest = pDest->eDest; /* How to dispose of results */
int iParm = pDest->iSDParm; /* First argument to disposal method */
int nResultCol; /* Number of result columns */
int nPrefixReg = 0; /* Number of extra registers before regResult */
RowLoadInfo sRowLoadInfo; /* Info for deferred row loading */
/* Usually, regResult is the first cell in an array of memory cells
** containing the current result row. In this case regOrig is set to the
** same value. However, if the results are being sent to the sorter, the
** values for any expressions that are also part of the sort-key are omitted
** from this array. In this case regOrig is set to zero. */
int regResult; /* Start of memory holding current results */
int regOrig; /* Start of memory holding full result (or 0) */
assert( v );
assert( p->pEList!=0 );
hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP;
if( pSort && pSort->pOrderBy==0 ) pSort = 0;
if( pSort==0 && !hasDistinct ){
assert( iContinue!=0 );
codeOffset(v, p->iOffset, iContinue);
}
/* Pull the requested columns.
*/
nResultCol = p->pEList->nExpr;
if( pDest->iSdst==0 ){
if( pSort ){
nPrefixReg = pSort->pOrderBy->nExpr;
if( !(pSort->sortFlags & SORTFLAG_UseSorter) ) nPrefixReg++;
pParse->nMem += nPrefixReg;
}
pDest->iSdst = pParse->nMem+1;
pParse->nMem += nResultCol;
}else if( pDest->iSdst+nResultCol > pParse->nMem ){
/* This is an error condition that can result, for example, when a SELECT
** on the right-hand side of an INSERT contains more result columns than
** there are columns in the table on the left. The error will be caught
** and reported later. But we need to make sure enough memory is allocated
** to avoid other spurious errors in the meantime. */
pParse->nMem += nResultCol;
}
pDest->nSdst = nResultCol;
regOrig = regResult = pDest->iSdst;
if( srcTab>=0 ){
for(i=0; i<nResultCol; i++){
sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
VdbeComment((v, "%s", p->pEList->a[i].zEName));
}
}else if( eDest!=SRT_Exists ){
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
ExprList *pExtra = 0;
#endif
/* If the destination is an EXISTS(...) expression, the actual
** values returned by the SELECT are not required.
*/
u8 ecelFlags; /* "ecel" is an abbreviation of "ExprCodeExprList" */
ExprList *pEList;
if( eDest==SRT_Mem || eDest==SRT_Output || eDest==SRT_Coroutine ){
ecelFlags = SQLITE_ECEL_DUP;
}else{
ecelFlags = 0;
}
if( pSort && hasDistinct==0 && eDest!=SRT_EphemTab && eDest!=SRT_Table ){
/* For each expression in p->pEList that is a copy of an expression in
** the ORDER BY clause (pSort->pOrderBy), set the associated
** iOrderByCol value to one more than the index of the ORDER BY
** expression within the sort-key that pushOntoSorter() will generate.
** This allows the p->pEList field to be omitted from the sorted record,
** saving space and CPU cycles. */
ecelFlags |= (SQLITE_ECEL_OMITREF|SQLITE_ECEL_REF);
for(i=pSort->nOBSat; i<pSort->pOrderBy->nExpr; i++){
int j;
if( (j = pSort->pOrderBy->a[i].u.x.iOrderByCol)>0 ){
p->pEList->a[j-1].u.x.iOrderByCol = i+1-pSort->nOBSat;
}
}
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
selectExprDefer(pParse, pSort, p->pEList, &pExtra);
if( pExtra && pParse->db->mallocFailed==0 ){
/* If there are any extra PK columns to add to the sorter records,
** allocate extra memory cells and adjust the OpenEphemeral
** instruction to account for the larger records. This is only
** required if there are one or more WITHOUT ROWID tables with
** composite primary keys in the SortCtx.aDefer[] array. */
VdbeOp *pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex);
pOp->p2 += (pExtra->nExpr - pSort->nDefer);
pOp->p4.pKeyInfo->nAllField += (pExtra->nExpr - pSort->nDefer);
pParse->nMem += pExtra->nExpr;
}
#endif
/* Adjust nResultCol to account for columns that are omitted
** from the sorter by the optimizations in this branch */
pEList = p->pEList;
for(i=0; i<pEList->nExpr; i++){
if( pEList->a[i].u.x.iOrderByCol>0
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
|| pEList->a[i].bSorterRef
#endif
){
nResultCol--;
regOrig = 0;
}
}
testcase( regOrig );
testcase( eDest==SRT_Set );
testcase( eDest==SRT_Mem );
testcase( eDest==SRT_Coroutine );
testcase( eDest==SRT_Output );
assert( eDest==SRT_Set || eDest==SRT_Mem
|| eDest==SRT_Coroutine || eDest==SRT_Output
|| eDest==SRT_Upfrom );
}
sRowLoadInfo.regResult = regResult;
sRowLoadInfo.ecelFlags = ecelFlags;
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
sRowLoadInfo.pExtra = pExtra;
sRowLoadInfo.regExtraResult = regResult + nResultCol;
if( pExtra ) nResultCol += pExtra->nExpr;
#endif
if( p->iLimit
&& (ecelFlags & SQLITE_ECEL_OMITREF)!=0
&& nPrefixReg>0
){
assert( pSort!=0 );
assert( hasDistinct==0 );
pSort->pDeferredRowLoad = &sRowLoadInfo;
regOrig = 0;
}else{
innerLoopLoadRow(pParse, p, &sRowLoadInfo);
}
}
/* If the DISTINCT keyword was present on the SELECT statement
** and this row has been seen before, then do not make this row
** part of the result.
*/
if( hasDistinct ){
switch( pDistinct->eTnctType ){
case WHERE_DISTINCT_ORDERED: {
VdbeOp *pOp; /* No longer required OpenEphemeral instr. */
int iJump; /* Jump destination */
int regPrev; /* Previous row content */
/* Allocate space for the previous row */
regPrev = pParse->nMem+1;
pParse->nMem += nResultCol;
/* Change the OP_OpenEphemeral coded earlier to an OP_Null
** sets the MEM_Cleared bit on the first register of the
** previous value. This will cause the OP_Ne below to always
** fail on the first iteration of the loop even if the first
** row is all NULLs.
*/
sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);
pOp = sqlite3VdbeGetOp(v, pDistinct->addrTnct);
pOp->opcode = OP_Null;
pOp->p1 = 1;
pOp->p2 = regPrev;
pOp = 0; /* Ensure pOp is not used after sqlite3VdbeAddOp() */
iJump = sqlite3VdbeCurrentAddr(v) + nResultCol;
for(i=0; i<nResultCol; i++){
CollSeq *pColl = sqlite3ExprCollSeq(pParse, p->pEList->a[i].pExpr);
if( i<nResultCol-1 ){
sqlite3VdbeAddOp3(v, OP_Ne, regResult+i, iJump, regPrev+i);
VdbeCoverage(v);
}else{
sqlite3VdbeAddOp3(v, OP_Eq, regResult+i, iContinue, regPrev+i);
VdbeCoverage(v);
}
sqlite3VdbeChangeP4(v, -1, (const char *)pColl, P4_COLLSEQ);
sqlite3VdbeChangeP5(v, SQLITE_NULLEQ);
}
assert( sqlite3VdbeCurrentAddr(v)==iJump || pParse->db->mallocFailed );
sqlite3VdbeAddOp3(v, OP_Copy, regResult, regPrev, nResultCol-1);
break;
}
case WHERE_DISTINCT_UNIQUE: {
sqlite3VdbeChangeToNoop(v, pDistinct->addrTnct);
break;
}
default: {
assert( pDistinct->eTnctType==WHERE_DISTINCT_UNORDERED );
codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol,
regResult);
break;
}
}
if( pSort==0 ){
codeOffset(v, p->iOffset, iContinue);
}
}
switch( eDest ){
/* In this mode, write each query result to the key of the temporary
** table iParm.
*/
#ifndef SQLITE_OMIT_COMPOUND_SELECT
case SRT_Union: {
int r1;
r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, nResultCol);
sqlite3ReleaseTempReg(pParse, r1);
break;
}
/* Construct a record from the query result, but instead of
** saving that record, use it as a key to delete elements from
** the temporary table iParm.
*/
case SRT_Except: {
sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nResultCol);
break;
}
#endif /* SQLITE_OMIT_COMPOUND_SELECT */
/* Store the result as data using a unique key.
*/
case SRT_Fifo:
case SRT_DistFifo:
case SRT_Table:
case SRT_EphemTab: {
int r1 = sqlite3GetTempRange(pParse, nPrefixReg+1);
testcase( eDest==SRT_Table );
testcase( eDest==SRT_EphemTab );
testcase( eDest==SRT_Fifo );
testcase( eDest==SRT_DistFifo );
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1+nPrefixReg);
#ifndef SQLITE_OMIT_CTE
if( eDest==SRT_DistFifo ){
/* If the destination is DistFifo, then cursor (iParm+1) is open
** on an ephemeral index. If the current row is already present
** in the index, do not write it to the output. If not, add the
** current row to the index and proceed with writing it to the
** output table as well. */
int addr = sqlite3VdbeCurrentAddr(v) + 4;
sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0);
VdbeCoverage(v);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm+1, r1,regResult,nResultCol);
assert( pSort==0 );
}
#endif
if( pSort ){
assert( regResult==regOrig );
pushOntoSorter(pParse, pSort, p, r1+nPrefixReg, regOrig, 1, nPrefixReg);
}else{
int r2 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
sqlite3ReleaseTempReg(pParse, r2);
}
sqlite3ReleaseTempRange(pParse, r1, nPrefixReg+1);
break;
}
case SRT_Upfrom: {
if( pSort ){
pushOntoSorter(
pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);
}else{
int i2 = pDest->iSDParm2;
int r1 = sqlite3GetTempReg(pParse);
/* If the UPDATE FROM join is an aggregate that matches no rows, it
** might still be trying to return one row, because that is what
** aggregates do. Don't record that empty row in the output table. */
sqlite3VdbeAddOp2(v, OP_IsNull, regResult, iBreak); VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_MakeRecord,
regResult+(i2<0), nResultCol-(i2<0), r1);
if( i2<0 ){
sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, regResult);
}else{
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, i2);
}
}
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
/* If we are creating a set for an "expr IN (SELECT ...)" construct,
** then there should be a single item on the stack. Write this
** item into the set table with bogus data.
*/
case SRT_Set: {
if( pSort ){
/* At first glance you would think we could optimize out the
** ORDER BY in this case since the order of entries in the set
** does not matter. But there might be a LIMIT clause, in which
** case the order does matter */
pushOntoSorter(
pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);
}else{
int r1 = sqlite3GetTempReg(pParse);
assert( sqlite3Strlen30(pDest->zAffSdst)==nResultCol );
sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, nResultCol,
r1, pDest->zAffSdst, nResultCol);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regResult, nResultCol);
sqlite3ReleaseTempReg(pParse, r1);
}
break;
}
/* If any row exist in the result set, record that fact and abort.
*/
case SRT_Exists: {
sqlite3VdbeAddOp2(v, OP_Integer, 1, iParm);
/* The LIMIT clause will terminate the loop for us */
break;
}
/* If this is a scalar select that is part of an expression, then
** store the results in the appropriate memory cell or array of
** memory cells and break out of the scan loop.
*/
case SRT_Mem: {
if( pSort ){
assert( nResultCol<=pDest->nSdst );
pushOntoSorter(
pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg);
}else{
assert( nResultCol==pDest->nSdst );
assert( regResult==iParm );
/* The LIMIT clause will jump out of the loop for us */
}
break;
}
#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
case SRT_Coroutine: /* Send data to a co-routine */
case SRT_Output: { /* Return the results */
testcase( eDest==SRT_Coroutine );
testcase( eDest==SRT_Output );
if( pSort ){
pushOntoSorter(pParse, pSort, p, regResult, regOrig, nResultCol,
nPrefixReg);
}else if( eDest==SRT_Coroutine ){
sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
}else{
sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nResultCol);
}
break;
}
#ifndef SQLITE_OMIT_CTE
/* Write the results into a priority queue that is order according to
** pDest->pOrderBy (in pSO). pDest->iSDParm (in iParm) is the cursor for an
** index with pSO->nExpr+2 columns. Build a key using pSO for the first
** pSO->nExpr columns, then make sure all keys are unique by adding a
** final OP_Sequence column. The last column is the record as a blob.
*/
case SRT_DistQueue:
case SRT_Queue: {
int nKey;
int r1, r2, r3;
int addrTest = 0;
ExprList *pSO;
pSO = pDest->pOrderBy;
assert( pSO );
nKey = pSO->nExpr;
r1 = sqlite3GetTempReg(pParse);
r2 = sqlite3GetTempRange(pParse, nKey+2);
r3 = r2+nKey+1;
if( eDest==SRT_DistQueue ){
/* If the destination is DistQueue, then cursor (iParm+1) is open
** on a second ephemeral index that holds all values every previously
** added to the queue. */
addrTest = sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, 0,
regResult, nResultCol);
VdbeCoverage(v);
}
sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r3);
if( eDest==SRT_DistQueue ){
sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r3);
sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
}
for(i=0; i<nKey; i++){
sqlite3VdbeAddOp2(v, OP_SCopy,
regResult + pSO->a[i].u.x.iOrderByCol - 1,
r2+i);
}
sqlite3VdbeAddOp2(v, OP_Sequence, iParm, r2+nKey);
sqlite3VdbeAddOp3(v, OP_MakeRecord, r2, nKey+2, r1);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, r2, nKey+2);
if( addrTest ) sqlite3VdbeJumpHere(v, addrTest);
sqlite3ReleaseTempReg(pParse, r1);
sqlite3ReleaseTempRange(pParse, r2, nKey+2);
break;
}
#endif /* SQLITE_OMIT_CTE */
#if !defined(SQLITE_OMIT_TRIGGER)
/* Discard the results. This is used for SELECT statements inside
** the body of a TRIGGER. The purpose of such selects is to call
** user-defined functions that have side effects. We do not care
** about the actual results of the select.
*/
default: {
assert( eDest==SRT_Discard );
break;
}
#endif
}
/* Jump to the end of the loop if the LIMIT is reached. Except, if
** there is a sorter, in which case the sorter has already limited
** the output for us.
*/
if( pSort==0 && p->iLimit ){
sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
}
}
/*
** Allocate a KeyInfo object sufficient for an index of N key columns and
** X extra columns.
*/
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N, int X){
int nExtra = (N+X)*(sizeof(CollSeq*)+1) - sizeof(CollSeq*);
KeyInfo *p = sqlite3DbMallocRawNN(db, sizeof(KeyInfo) + nExtra);
if( p ){
p->aSortFlags = (u8*)&p->aColl[N+X];
p->nKeyField = (u16)N;
p->nAllField = (u16)(N+X);
p->enc = ENC(db);
p->db = db;
p->nRef = 1;
memset(&p[1], 0, nExtra);
}else{
sqlite3OomFault(db);
}
return p;
}
/*
** Deallocate a KeyInfo object
*/
SQLITE_PRIVATE void sqlite3KeyInfoUnref(KeyInfo *p){
if( p ){
assert( p->nRef>0 );
p->nRef--;
if( p->nRef==0 ) sqlite3DbFreeNN(p->db, p);
}
}
/*
** Make a new pointer to a KeyInfo object
*/
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoRef(KeyInfo *p){
if( p ){
assert( p->nRef>0 );
p->nRef++;
}
return p;
}
#ifdef SQLITE_DEBUG
/*
** Return TRUE if a KeyInfo object can be change. The KeyInfo object
** can only be changed if this is just a single reference to the object.
**
** This routine is used only inside of assert() statements.
*/
SQLITE_PRIVATE int sqlite3KeyInfoIsWriteable(KeyInfo *p){ return p->nRef==1; }
#endif /* SQLITE_DEBUG */
/*
** Given an expression list, generate a KeyInfo structure that records
** the collating sequence for each expression in that expression list.
**
** If the ExprList is an ORDER BY or GROUP BY clause then the resulting
** KeyInfo structure is appropriate for initializing a virtual index to
** implement that clause. If the ExprList is the result set of a SELECT
** then the KeyInfo structure is appropriate for initializing a virtual
** index to implement a DISTINCT test.
**
** Space to hold the KeyInfo structure is obtained from malloc. The calling
** function is responsible for seeing that this structure is eventually
** freed.
*/
SQLITE_PRIVATE KeyInfo *sqlite3KeyInfoFromExprList(
Parse *pParse, /* Parsing context */
ExprList *pList, /* Form the KeyInfo object from this ExprList */
int iStart, /* Begin with this column of pList */
int nExtra /* Add this many extra columns to the end */
){
int nExpr;
KeyInfo *pInfo;
struct ExprList_item *pItem;
sqlite3 *db = pParse->db;
int i;
nExpr = pList->nExpr;
pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);
if( pInfo ){
assert( sqlite3KeyInfoIsWriteable(pInfo) );
for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){
pInfo->aColl[i-iStart] = sqlite3ExprNNCollSeq(pParse, pItem->pExpr);
pInfo->aSortFlags[i-iStart] = pItem->sortFlags;
}
}
return pInfo;
}
/*
** Name of the connection operator, used for error messages.
*/
static const char *selectOpName(int id){
char *z;
switch( id ){
case TK_ALL: z = "UNION ALL"; break;
case TK_INTERSECT: z = "INTERSECT"; break;
case TK_EXCEPT: z = "EXCEPT"; break;
default: z = "UNION"; break;
}
return z;
}
#ifndef SQLITE_OMIT_EXPLAIN
/*
** Unless an "EXPLAIN QUERY PLAN" command is being processed, this function
** is a no-op. Otherwise, it adds a single row of output to the EQP result,
** where the caption is of the form:
**
** "USE TEMP B-TREE FOR xxx"
**
** where xxx is one of "DISTINCT", "ORDER BY" or "GROUP BY". Exactly which
** is determined by the zUsage argument.
*/
static void explainTempTable(Parse *pParse, const char *zUsage){
ExplainQueryPlan((pParse, 0, "USE TEMP B-TREE FOR %s", zUsage));
}
/*
** Assign expression b to lvalue a. A second, no-op, version of this macro
** is provided when SQLITE_OMIT_EXPLAIN is defined. This allows the code
** in sqlite3Select() to assign values to structure member variables that
** only exist if SQLITE_OMIT_EXPLAIN is not defined without polluting the
** code with #ifndef directives.
*/
# define explainSetInteger(a, b) a = b
#else
/* No-op versions of the explainXXX() functions and macros. */
# define explainTempTable(y,z)
# define explainSetInteger(y,z)
#endif
/*
** If the inner loop was generated using a non-null pOrderBy argument,
** then the results were placed in a sorter. After the loop is terminated
** we need to run the sorter and output the results. The following
** routine generates the code needed to do that.
*/
static void generateSortTail(
Parse *pParse, /* Parsing context */
Select *p, /* The SELECT statement */
SortCtx *pSort, /* Information on the ORDER BY clause */
int nColumn, /* Number of columns of data */
SelectDest *pDest /* Write the sorted results here */
){
Vdbe *v = pParse->pVdbe; /* The prepared statement */
int addrBreak = pSort->labelDone; /* Jump here to exit loop */
int addrContinue = sqlite3VdbeMakeLabel(pParse);/* Jump here for next cycle */
int addr; /* Top of output loop. Jump for Next. */
int addrOnce = 0;
int iTab;
ExprList *pOrderBy = pSort->pOrderBy;
int eDest = pDest->eDest;
int iParm = pDest->iSDParm;
int regRow;
int regRowid;
int iCol;
int nKey; /* Number of key columns in sorter record */
int iSortTab; /* Sorter cursor to read from */
int i;
int bSeq; /* True if sorter record includes seq. no. */
int nRefKey = 0;
struct ExprList_item *aOutEx = p->pEList->a;
assert( addrBreak<0 );
if( pSort->labelBkOut ){
sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut);
sqlite3VdbeGoto(v, addrBreak);
sqlite3VdbeResolveLabel(v, pSort->labelBkOut);
}
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
/* Open any cursors needed for sorter-reference expressions */
for(i=0; i<pSort->nDefer; i++){
Table *pTab = pSort->aDefer[i].pTab;
int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
sqlite3OpenTable(pParse, pSort->aDefer[i].iCsr, iDb, pTab, OP_OpenRead);
nRefKey = MAX(nRefKey, pSort->aDefer[i].nKey);
}
#endif
iTab = pSort->iECursor;
if( eDest==SRT_Output || eDest==SRT_Coroutine || eDest==SRT_Mem ){
regRowid = 0;
regRow = pDest->iSdst;
}else{
regRowid = sqlite3GetTempReg(pParse);
if( eDest==SRT_EphemTab || eDest==SRT_Table ){
regRow = sqlite3GetTempReg(pParse);
nColumn = 0;
}else{
regRow = sqlite3GetTempRange(pParse, nColumn);
}
}
nKey = pOrderBy->nExpr - pSort->nOBSat;
if( pSort->sortFlags & SORTFLAG_UseSorter ){
int regSortOut = ++pParse->nMem;
iSortTab = pParse->nTab++;
if( pSort->labelBkOut ){
addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
}
sqlite3VdbeAddOp3(v, OP_OpenPseudo, iSortTab, regSortOut,
nKey+1+nColumn+nRefKey);
if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce);
addr = 1 + sqlite3VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak);
VdbeCoverage(v);
codeOffset(v, p->iOffset, addrContinue);
sqlite3VdbeAddOp3(v, OP_SorterData, iTab, regSortOut, iSortTab);
bSeq = 0;
}else{
addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); VdbeCoverage(v);
codeOffset(v, p->iOffset, addrContinue);
iSortTab = iTab;
bSeq = 1;
}
for(i=0, iCol=nKey+bSeq-1; i<nColumn; i++){
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
if( aOutEx[i].bSorterRef ) continue;
#endif
if( aOutEx[i].u.x.iOrderByCol==0 ) iCol++;
}
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
if( pSort->nDefer ){
int iKey = iCol+1;
int regKey = sqlite3GetTempRange(pParse, nRefKey);
for(i=0; i<pSort->nDefer; i++){
int iCsr = pSort->aDefer[i].iCsr;
Table *pTab = pSort->aDefer[i].pTab;
int nKey = pSort->aDefer[i].nKey;
sqlite3VdbeAddOp1(v, OP_NullRow, iCsr);
if( HasRowid(pTab) ){
sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iKey++, regKey);
sqlite3VdbeAddOp3(v, OP_SeekRowid, iCsr,
sqlite3VdbeCurrentAddr(v)+1, regKey);
}else{
int k;
int iJmp;
assert( sqlite3PrimaryKeyIndex(pTab)->nKeyCol==nKey );
for(k=0; k<nKey; k++){
sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iKey++, regKey+k);
}
iJmp = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp4Int(v, OP_SeekGE, iCsr, iJmp+2, regKey, nKey);
sqlite3VdbeAddOp4Int(v, OP_IdxLE, iCsr, iJmp+3, regKey, nKey);
sqlite3VdbeAddOp1(v, OP_NullRow, iCsr);
}
}
sqlite3ReleaseTempRange(pParse, regKey, nRefKey);
}
#endif
for(i=nColumn-1; i>=0; i--){
#ifdef SQLITE_ENABLE_SORTER_REFERENCES
if( aOutEx[i].bSorterRef ){
sqlite3ExprCode(pParse, aOutEx[i].pExpr, regRow+i);
}else
#endif
{
int iRead;
if( aOutEx[i].u.x.iOrderByCol ){
iRead = aOutEx[i].u.x.iOrderByCol-1;
}else{
iRead = iCol--;
}
sqlite3VdbeAddOp3(v, OP_Column, iSortTab, iRead, regRow+i);
VdbeComment((v, "%s", aOutEx[i].zEName));
}
}
switch( eDest ){
case SRT_Table:
case SRT_EphemTab: {
sqlite3VdbeAddOp3(v, OP_Column, iSortTab, nKey+bSeq, regRow);
sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid);
sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case SRT_Set: {
assert( nColumn==sqlite3Strlen30(pDest->zAffSdst) );
sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, nColumn, regRowid,
pDest->zAffSdst, nColumn);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, regRowid, regRow, nColumn);
break;
}
case SRT_Mem: {
/* The LIMIT clause will terminate the loop for us */
break;
}
#endif
case SRT_Upfrom: {
int i2 = pDest->iSDParm2;
int r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_MakeRecord,regRow+(i2<0),nColumn-(i2<0),r1);
if( i2<0 ){
sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, regRow);
}else{
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iParm, r1, regRow, i2);
}
break;
}
default: {
assert( eDest==SRT_Output || eDest==SRT_Coroutine );
testcase( eDest==SRT_Output );
testcase( eDest==SRT_Coroutine );
if( eDest==SRT_Output ){
sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iSdst, nColumn);
}else{
sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
}
break;
}
}
if( regRowid ){
if( eDest==SRT_Set ){
sqlite3ReleaseTempRange(pParse, regRow, nColumn);
}else{
sqlite3ReleaseTempReg(pParse, regRow);
}
sqlite3ReleaseTempReg(pParse, regRowid);
}
/* The bottom of the loop
*/
sqlite3VdbeResolveLabel(v, addrContinue);
if( pSort->sortFlags & SORTFLAG_UseSorter ){
sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr); VdbeCoverage(v);
}else{
sqlite3VdbeAddOp2(v, OP_Next, iTab, addr); VdbeCoverage(v);
}
if( pSort->regReturn ) sqlite3VdbeAddOp1(v, OP_Return, pSort->regReturn);
sqlite3VdbeResolveLabel(v, addrBreak);
}
/*
** Return a pointer to a string containing the 'declaration type' of the
** expression pExpr. The string may be treated as static by the caller.
**
** Also try to estimate the size of the returned value and return that
** result in *pEstWidth.
**
** The declaration type is the exact datatype definition extracted from the
** original CREATE TABLE statement if the expression is a column. The
** declaration type for a ROWID field is INTEGER. Exactly when an expression
** is considered a column can be complex in the presence of subqueries. The
** result-set expression in all of the following SELECT statements is
** considered a column by this function.
**
** SELECT col FROM tbl;
** SELECT (SELECT col FROM tbl;
** SELECT (SELECT col FROM tbl);
** SELECT abc FROM (SELECT col AS abc FROM tbl);
**
** The declaration type for any expression other than a column is NULL.
**
** This routine has either 3 or 6 parameters depending on whether or not
** the SQLITE_ENABLE_COLUMN_METADATA compile-time option is used.
*/
#ifdef SQLITE_ENABLE_COLUMN_METADATA
# define columnType(A,B,C,D,E) columnTypeImpl(A,B,C,D,E)
#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */
# define columnType(A,B,C,D,E) columnTypeImpl(A,B)
#endif
static const char *columnTypeImpl(
NameContext *pNC,
#ifndef SQLITE_ENABLE_COLUMN_METADATA
Expr *pExpr
#else
Expr *pExpr,
const char **pzOrigDb,
const char **pzOrigTab,
const char **pzOrigCol
#endif
){
char const *zType = 0;
int j;
#ifdef SQLITE_ENABLE_COLUMN_METADATA
char const *zOrigDb = 0;
char const *zOrigTab = 0;
char const *zOrigCol = 0;
#endif
assert( pExpr!=0 );
assert( pNC->pSrcList!=0 );
switch( pExpr->op ){
case TK_COLUMN: {
/* The expression is a column. Locate the table the column is being
** extracted from in NameContext.pSrcList. This table may be real
** database table or a subquery.
*/
Table *pTab = 0; /* Table structure column is extracted from */
Select *pS = 0; /* Select the column is extracted from */
int iCol = pExpr->iColumn; /* Index of column in pTab */
while( pNC && !pTab ){
SrcList *pTabList = pNC->pSrcList;
for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
if( j<pTabList->nSrc ){
pTab = pTabList->a[j].pTab;
pS = pTabList->a[j].pSelect;
}else{
pNC = pNC->pNext;
}
}
if( pTab==0 ){
/* At one time, code such as "SELECT new.x" within a trigger would
** cause this condition to run. Since then, we have restructured how
** trigger code is generated and so this condition is no longer
** possible. However, it can still be true for statements like
** the following:
**
** CREATE TABLE t1(col INTEGER);
** SELECT (SELECT t1.col) FROM FROM t1;
**
** when columnType() is called on the expression "t1.col" in the
** sub-select. In this case, set the column type to NULL, even
** though it should really be "INTEGER".
**
** This is not a problem, as the column type of "t1.col" is never
** used. When columnType() is called on the expression
** "(SELECT t1.col)", the correct type is returned (see the TK_SELECT
** branch below. */
break;
}
assert( pTab && pExpr->y.pTab==pTab );
if( pS ){
/* The "table" is actually a sub-select or a view in the FROM clause
** of the SELECT statement. Return the declaration type and origin
** data for the result-set column of the sub-select.
*/
if( iCol>=0 && iCol<pS->pEList->nExpr ){
/* If iCol is less than zero, then the expression requests the
** rowid of the sub-select or view. This expression is legal (see
** test case misc2.2.2) - it always evaluates to NULL.
*/
NameContext sNC;
Expr *p = pS->pEList->a[iCol].pExpr;
sNC.pSrcList = pS->pSrc;
sNC.pNext = pNC;
sNC.pParse = pNC->pParse;
zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol);
}
}else{
/* A real table or a CTE table */
assert( !pS );
#ifdef SQLITE_ENABLE_COLUMN_METADATA
if( iCol<0 ) iCol = pTab->iPKey;
assert( iCol==XN_ROWID || (iCol>=0 && iCol<pTab->nCol) );
if( iCol<0 ){
zType = "INTEGER";
zOrigCol = "rowid";
}else{
zOrigCol = pTab->aCol[iCol].zName;
zType = sqlite3ColumnType(&pTab->aCol[iCol],0);
}
zOrigTab = pTab->zName;
if( pNC->pParse && pTab->pSchema ){
int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
zOrigDb = pNC->pParse->db->aDb[iDb].zDbSName;
}
#else
assert( iCol==XN_ROWID || (iCol>=0 && iCol<pTab->nCol) );
if( iCol<0 ){
zType = "INTEGER";
}else{
zType = sqlite3ColumnType(&pTab->aCol[iCol],0);
}
#endif
}
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
case TK_SELECT: {
/* The expression is a sub-select. Return the declaration type and
** origin info for the single column in the result set of the SELECT
** statement.
*/
NameContext sNC;
Select *pS = pExpr->x.pSelect;
Expr *p = pS->pEList->a[0].pExpr;
assert( ExprHasProperty(pExpr, EP_xIsSelect) );
sNC.pSrcList = pS->pSrc;
sNC.pNext = pNC;
sNC.pParse = pNC->pParse;
zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
break;
}
#endif
}
#ifdef SQLITE_ENABLE_COLUMN_METADATA
if( pzOrigDb ){
assert( pzOrigTab && pzOrigCol );
*pzOrigDb = zOrigDb;
*pzOrigTab = zOrigTab;
*pzOrigCol = zOrigCol;
}
#endif
return zType;
}
/*
** Generate code that will tell the VDBE the declaration types of columns
** in the result set.
*/
static void generateColumnTypes(
Parse *pParse, /* Parser context */
SrcList *pTabList, /* List of tables */
ExprList *pEList /* Expressions defining the result set */
){
#ifndef SQLITE_OMIT_DECLTYPE
Vdbe *v = pParse->pVdbe;
int i;
NameContext sNC;
sNC.pSrcList = pTabList;
sNC.pParse = pParse;
sNC.pNext = 0;
for(i=0; i<pEList->nExpr; i++){
Expr *p = pEList->a[i].pExpr;
const char *zType;
#ifdef SQLITE_ENABLE_COLUMN_METADATA
const char *zOrigDb = 0;
const char *zOrigTab = 0;
const char *zOrigCol = 0;
zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
/* The vdbe must make its own copy of the column-type and other
** column specific strings, in case the schema is reset before this
** virtual machine is deleted.
*/
sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, SQLITE_TRANSIENT);
sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, SQLITE_TRANSIENT);
sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, SQLITE_TRANSIENT);
#else
zType = columnType(&sNC, p, 0, 0, 0);
#endif
sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);
}
#endif /* !defined(SQLITE_OMIT_DECLTYPE) */
}
/*
** Compute the column names for a SELECT statement.
**
** The only guarantee that SQLite makes about column names is that if the
** column has an AS clause assigning it a name, that will be the name used.
** That is the only documented guarantee. However, countless applications
** developed over the years have made baseless assumptions about column names
** and will break if those assumptions changes. Hence, use extreme caution
** when modifying this routine to avoid breaking legacy.
**
** See Also: sqlite3ColumnsFromExprList()
**
** The PRAGMA short_column_names and PRAGMA full_column_names settings are
** deprecated. The default setting is short=ON, full=OFF. 99.9% of all
** applications should operate this way. Nevertheless, we need to support the
** other modes for legacy:
**
** short=OFF, full=OFF: Column name is the text of the expression has it
** originally appears in the SELECT statement. In
** other words, the zSpan of the result expression.
**
** short=ON, full=OFF: (This is the default setting). If the result
** refers directly to a table column, then the
** result column name is just the table column
** name: COLUMN. Otherwise use zSpan.
**
** full=ON, short=ANY: If the result refers directly to a table column,
** then the result column name with the table name
** prefix, ex: TABLE.COLUMN. Otherwise use zSpan.
*/
static void generateColumnNames(
Parse *pParse, /* Parser context */
Select *pSelect /* Generate column names for this SELECT statement */
){
Vdbe *v = pParse->pVdbe;
int i;
Table *pTab;
SrcList *pTabList;
ExprList *pEList;
sqlite3 *db = pParse->db;
int fullName; /* TABLE.COLUMN if no AS clause and is a direct table ref */
int srcName; /* COLUMN or TABLE.COLUMN if no AS clause and is direct */
#ifndef SQLITE_OMIT_EXPLAIN
/* If this is an EXPLAIN, skip this step */
if( pParse->explain ){
return;
}
#endif
if( pParse->colNamesSet ) return;
/* Column names are determined by the left-most term of a compound select */
while( pSelect->pPrior ) pSelect = pSelect->pPrior;
SELECTTRACE(1,pParse,pSelect,("generating column names\n"));
pTabList = pSelect->pSrc;
pEList = pSelect->pEList;
assert( v!=0 );
assert( pTabList!=0 );
pParse->colNamesSet = 1;
fullName = (db->flags & SQLITE_FullColNames)!=0;
srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName;
sqlite3VdbeSetNumCols(v, pEList->nExpr);
for(i=0; i<pEList->nExpr; i++){
Expr *p = pEList->a[i].pExpr;
assert( p!=0 );
assert( p->op!=TK_AGG_COLUMN ); /* Agg processing has not run yet */
assert( p->op!=TK_COLUMN || p->y.pTab!=0 ); /* Covering idx not yet coded */
if( pEList->a[i].zEName && pEList->a[i].eEName==ENAME_NAME ){
/* An AS clause always takes first priority */
char *zName = pEList->a[i].zEName;
sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
}else if( srcName && p->op==TK_COLUMN ){
char *zCol;
int iCol = p->iColumn;
pTab = p->y.pTab;
assert( pTab!=0 );
if( iCol<0 ) iCol = pTab->iPKey;
assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
if( iCol<0 ){
zCol = "rowid";
}else{
zCol = pTab->aCol[iCol].zName;
}
if( fullName ){
char *zName = 0;
zName = sqlite3MPrintf(db, "%s.%s", pTab->zName, zCol);
sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_DYNAMIC);
}else{
sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);
}
}else{
const char *z = pEList->a[i].zEName;
z = z==0 ? sqlite3MPrintf(db, "column%d", i+1) : sqlite3DbStrDup(db, z);
sqlite3VdbeSetColName(v, i, COLNAME_NAME, z, SQLITE_DYNAMIC);
}
}
generateColumnTypes(pParse, pTabList, pEList);
}
/*
** Given an expression list (which is really the list of expressions
** that form the result set of a SELECT statement) compute appropriate
** column names for a table that would hold the expression list.
**
** All column names will be unique.
**
** Only the column names are computed. Column.zType, Column.zColl,
** and other fields of Column are zeroed.
**
** Return SQLITE_OK on success. If a memory allocation error occurs,
** store NULL in *paCol and 0 in *pnCol and return SQLITE_NOMEM.
**
** The only guarantee that SQLite makes about column names is that if the
** column has an AS clause assigning it a name, that will be the name used.
** That is the only documented guarantee. However, countless applications
** developed over the years have made baseless assumptions about column names
** and will break if those assumptions changes. Hence, use extreme caution
** when modifying this routine to avoid breaking legacy.
**
** See Also: generateColumnNames()
*/
SQLITE_PRIVATE int sqlite3ColumnsFromExprList(
Parse *pParse, /* Parsing context */
ExprList *pEList, /* Expr list from which to derive column names */
i16 *pnCol, /* Write the number of columns here */
Column **paCol /* Write the new column list here */
){
sqlite3 *db = pParse->db; /* Database connection */
int i, j; /* Loop counters */
u32 cnt; /* Index added to make the name unique */
Column *aCol, *pCol; /* For looping over result columns */
int nCol; /* Number of columns in the result set */
char *zName; /* Column name */
int nName; /* Size of name in zName[] */
Hash ht; /* Hash table of column names */
Table *pTab;
sqlite3HashInit(&ht);
if( pEList ){
nCol = pEList->nExpr;
aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
testcase( aCol==0 );
if( nCol>32767 ) nCol = 32767;
}else{
nCol = 0;
aCol = 0;
}
assert( nCol==(i16)nCol );
*pnCol = nCol;
*paCol = aCol;
for(i=0, pCol=aCol; i<nCol && !db->mallocFailed; i++, pCol++){
/* Get an appropriate name for the column
*/
if( (zName = pEList->a[i].zEName)!=0 && pEList->a[i].eEName==ENAME_NAME ){
/* If the column contains an "AS <name>" phrase, use <name> as the name */
}else{
Expr *pColExpr = sqlite3ExprSkipCollateAndLikely(pEList->a[i].pExpr);
while( ALWAYS(pColExpr!=0) && pColExpr->op==TK_DOT ){
pColExpr = pColExpr->pRight;
assert( pColExpr!=0 );
}
if( pColExpr->op==TK_COLUMN && (pTab = pColExpr->y.pTab)!=0 ){
/* For columns use the column name name */
int iCol = pColExpr->iColumn;
if( iCol<0 ) iCol = pTab->iPKey;
zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";
}else if( pColExpr->op==TK_ID ){
assert( !ExprHasProperty(pColExpr, EP_IntValue) );
zName = pColExpr->u.zToken;
}else{
/* Use the original text of the column expression as its name */
zName = pEList->a[i].zEName;
}
}
if( zName && !sqlite3IsTrueOrFalse(zName) ){
zName = sqlite3DbStrDup(db, zName);
}else{
zName = sqlite3MPrintf(db,"column%d",i+1);
}
/* Make sure the column name is unique. If the name is not unique,
** append an integer to the name so that it becomes unique.
*/
cnt = 0;
while( zName && sqlite3HashFind(&ht, zName)!=0 ){
nName = sqlite3Strlen30(zName);
if( nName>0 ){
for(j=nName-1; j>0 && sqlite3Isdigit(zName[j]); j--){}
if( zName[j]==':' ) nName = j;
}
zName = sqlite3MPrintf(db, "%.*z:%u", nName, zName, ++cnt);
if( cnt>3 ) sqlite3_randomness(sizeof(cnt), &cnt);
}
pCol->zName = zName;
pCol->hName = sqlite3StrIHash(zName);
sqlite3ColumnPropertiesFromName(0, pCol);
if( zName && sqlite3HashInsert(&ht, zName, pCol)==pCol ){
sqlite3OomFault(db);
}
}
sqlite3HashClear(&ht);
if( db->mallocFailed ){
for(j=0; j<i; j++){
sqlite3DbFree(db, aCol[j].zName);
}
sqlite3DbFree(db, aCol);
*paCol = 0;
*pnCol = 0;
return SQLITE_NOMEM_BKPT;
}
return SQLITE_OK;
}
/*
** Add type and collation information to a column list based on
** a SELECT statement.
**
** The column list presumably came from selectColumnNamesFromExprList().
** The column list has only names, not types or collations. This
** routine goes through and adds the types and collations.
**
** This routine requires that all identifiers in the SELECT
** statement be resolved.
*/
SQLITE_PRIVATE void sqlite3SelectAddColumnTypeAndCollation(
Parse *pParse, /* Parsing contexts */
Table *pTab, /* Add column type information to this table */
Select *pSelect, /* SELECT used to determine types and collations */
char aff /* Default affinity for columns */
){
sqlite3 *db = pParse->db;
NameContext sNC;
Column *pCol;
CollSeq *pColl;
int i;
Expr *p;
struct ExprList_item *a;
assert( pSelect!=0 );
assert( (pSelect->selFlags & SF_Resolved)!=0 );
assert( pTab->nCol==pSelect->pEList->nExpr || db->mallocFailed );
if( db->mallocFailed ) return;
memset(&sNC, 0, sizeof(sNC));
sNC.pSrcList = pSelect->pSrc;
a = pSelect->pEList->a;
for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
const char *zType;
int n, m;
p = a[i].pExpr;
zType = columnType(&sNC, p, 0, 0, 0);
/* pCol->szEst = ... // Column size est for SELECT tables never used */
pCol->affinity = sqlite3ExprAffinity(p);
if( zType ){
m = sqlite3Strlen30(zType);
n = sqlite3Strlen30(pCol->zName);
pCol->zName = sqlite3DbReallocOrFree(db, pCol->zName, n+m+2);
if( pCol->zName ){
memcpy(&pCol->zName[n+1], zType, m+1);
pCol->colFlags |= COLFLAG_HASTYPE;
}
}
if( pCol->affinity<=SQLITE_AFF_NONE ) pCol->affinity = aff;
pColl = sqlite3ExprCollSeq(pParse, p);
if( pColl && pCol->zColl==0 ){
pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
}
}
pTab->szTabRow = 1; /* Any non-zero value works */
}
/*
** Given a SELECT statement, generate a Table structure that describes
** the result set of that SELECT.
*/
SQLITE_PRIVATE Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect, char aff){
Table *pTab;
sqlite3 *db = pParse->db;
u64 savedFlags;
savedFlags = db->flags;
db->flags &= ~(u64)SQLITE_FullColNames;
db->flags |= SQLITE_ShortColNames;
sqlite3SelectPrep(pParse, pSelect, 0);
db->flags = savedFlags;
if( pParse->nErr ) return 0;
while( pSelect->pPrior ) pSelect = pSelect->pPrior;
pTab = sqlite3DbMallocZero(db, sizeof(Table) );
if( pTab==0 ){
return 0;
}
pTab->nTabRef = 1;
pTab->zName = 0;
pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
sqlite3ColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSelect, aff);
pTab->iPKey = -1;
if( db->mallocFailed ){
sqlite3DeleteTable(db, pTab);
return 0;
}
return pTab;
}
/*
** Get a VDBE for the given parser context. Create a new one if necessary.
** If an error occurs, return NULL and leave a message in pParse.
*/
SQLITE_PRIVATE Vdbe *sqlite3GetVdbe(Parse *pParse){
if( pParse->pVdbe ){
return pParse->pVdbe;
}
if( pParse->pToplevel==0
&& OptimizationEnabled(pParse->db,SQLITE_FactorOutConst)
){
pParse->okConstFactor = 1;
}
return sqlite3VdbeCreate(pParse);
}
/*
** Compute the iLimit and iOffset fields of the SELECT based on the
** pLimit expressions. pLimit->pLeft and pLimit->pRight hold the expressions
** that appear in the original SQL statement after the LIMIT and OFFSET
** keywords. Or NULL if those keywords are omitted. iLimit and iOffset
** are the integer memory register numbers for counters used to compute
** the limit and offset. If there is no limit and/or offset, then
** iLimit and iOffset are negative.
**
** This routine changes the values of iLimit and iOffset only if
** a limit or offset is defined by pLimit->pLeft and pLimit->pRight. iLimit
** and iOffset should have been preset to appropriate default values (zero)
** prior to calling this routine.
**
** The iOffset register (if it exists) is initialized to the value
** of the OFFSET. The iLimit register is initialized to LIMIT. Register
** iOffset+1 is initialized to LIMIT+OFFSET.
**
** Only if pLimit->pLeft!=0 do the limit registers get
** redefined. The UNION ALL operator uses this property to force
** the reuse of the same limit and offset registers across multiple
** SELECT statements.
*/
static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
Vdbe *v = 0;
int iLimit = 0;
int iOffset;
int n;
Expr *pLimit = p->pLimit;
if( p->iLimit ) return;
/*
** "LIMIT -1" always shows all rows. There is some
** controversy about what the correct behavior should be.
** The current implementation interprets "LIMIT 0" to mean
** no rows.
*/
if( pLimit ){
assert( pLimit->op==TK_LIMIT );
assert( pLimit->pLeft!=0 );
p->iLimit = iLimit = ++pParse->nMem;
v = sqlite3GetVdbe(pParse);
assert( v!=0 );
if( sqlite3ExprIsInteger(pLimit->pLeft, &n) ){
sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit);
VdbeComment((v, "LIMIT counter"));
if( n==0 ){
sqlite3VdbeGoto(v, iBreak);
}else if( n>=0 && p->nSelectRow>sqlite3LogEst((u64)n) ){
p->nSelectRow = sqlite3LogEst((u64)n);
p->selFlags |= SF_FixedLimit;
}
}else{
sqlite3ExprCode(pParse, pLimit->pLeft, iLimit);
sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); VdbeCoverage(v);
VdbeComment((v, "LIMIT counter"));
sqlite3VdbeAddOp2(v, OP_IfNot, iLimit, iBreak); VdbeCoverage(v);
}
if( pLimit->pRight ){
p->iOffset = iOffset = ++pParse->nMem;
pParse->nMem++; /* Allocate an extra register for limit+offset */
sqlite3ExprCode(pParse, pLimit->pRight, iOffset);
sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); VdbeCoverage(v);
VdbeComment((v, "OFFSET counter"));
sqlite3VdbeAddOp3(v, OP_OffsetLimit, iLimit, iOffset+1, iOffset);
VdbeComment((v, "LIMIT+OFFSET"));
}
}
}
#ifndef SQLITE_OMIT_COMPOUND_SELECT
/*
** Return the appropriate collating sequence for the iCol-th column of
** the result set for the compound-select statement "p". Return NULL if
** the column has no default collating sequence.
**
** The collating sequence for the compound select is taken from the
** left-most term of the select that has a collating sequence.
*/
static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){
CollSeq *pRet;
if( p->pPrior ){
pRet = multiSelectCollSeq(pParse, p->pPrior, iCol);
}else{
pRet = 0;
}
assert( iCol>=0 );
/* iCol must be less than p->pEList->nExpr. Otherwise an error would
** have been thrown during name resolution and we would not have gotten
** this far */
if( pRet==0 && ALWAYS(iCol<p->pEList->nExpr) ){
pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
}
return pRet;
}
/*
** The select statement passed as the second parameter is a compound SELECT
** with an ORDER BY clause. This function allocates and returns a KeyInfo
** structure suitable for implementing the ORDER BY.
**
** Space to hold the KeyInfo structure is obtained from malloc. The calling
** function is responsible for ensuring that this structure is eventually
** freed.
*/
static KeyInfo *multiSelectOrderByKeyInfo(Parse *pParse, Select *p, int nExtra){
ExprList *pOrderBy = p->pOrderBy;
int nOrderBy = p->pOrderBy->nExpr;
sqlite3 *db = pParse->db;
KeyInfo *pRet = sqlite3KeyInfoAlloc(db, nOrderBy+nExtra, 1);
if( pRet ){
int i;
for(i=0; i<nOrderBy; i++){
struct ExprList_item *pItem = &pOrderBy->a[i];
Expr *pTerm = pItem->pExpr;
CollSeq *pColl;
if( pTerm->flags & EP_Collate ){
pColl = sqlite3ExprCollSeq(pParse, pTerm);
}else{
pColl = multiSelectCollSeq(pParse, p, pItem->u.x.iOrderByCol-1);
if( pColl==0 ) pColl = db->pDfltColl;
pOrderBy->a[i].pExpr =
sqlite3ExprAddCollateString(pParse, pTerm, pColl->zName);
}
assert( sqlite3KeyInfoIsWriteable(pRet) );
pRet->aColl[i] = pColl;
pRet->aSortFlags[i] = pOrderBy->a[i].sortFlags;
}
}
return pRet;
}
#ifndef SQLITE_OMIT_CTE
/*
** This routine generates VDBE code to compute the content of a WITH RECURSIVE
** query of the form:
**
** <recursive-table> AS (<setup-query> UNION [ALL] <recursive-query>)
** \___________/ \_______________/
** p->pPrior p
**
**
** There is exactly one reference to the recursive-table in the FROM clause
** of recursive-query, marked with the SrcList->a[].fg.isRecursive flag.
**
** The setup-query runs once to generate an initial set of rows that go
** into a Queue table. Rows are extracted from the Queue table one by
** one. Each row extracted from Queue is output to pDest. Then the single
** extracted row (now in the iCurrent table) becomes the content of the
** recursive-table for a recursive-query run. The output of the recursive-query
** is added back into the Queue table. Then another row is extracted from Queue
** and the iteration continues until the Queue table is empty.
**
** If the compound query operator is UNION then no duplicate rows are ever
** inserted into the Queue table. The iDistinct table keeps a copy of all rows
** that have ever been inserted into Queue and causes duplicates to be
** discarded. If the operator is UNION ALL, then duplicates are allowed.
**
** If the query has an ORDER BY, then entries in the Queue table are kept in
** ORDER BY order and the first entry is extracted for each cycle. Without
** an ORDER BY, the Queue table is just a FIFO.
**
** If a LIMIT clause is provided, then the iteration stops after LIMIT rows
** have been output to pDest. A LIMIT of zero means to output no rows and a
** negative LIMIT means to output all rows. If there is also an OFFSET clause
** with a positive value, then the first OFFSET outputs are discarded rather
** than being sent to pDest. The LIMIT count does not begin until after OFFSET
** rows have been skipped.
*/
static void generateWithRecursiveQuery(
Parse *pParse, /* Parsing context */
Select *p, /* The recursive SELECT to be coded */
SelectDest *pDest /* What to do with query results */
){
SrcList *pSrc = p->pSrc; /* The FROM clause of the recursive query */
int nCol = p->pEList->nExpr; /* Number of columns in the recursive table */
Vdbe *v = pParse->pVdbe; /* The prepared statement under construction */
Select *pSetup = p->pPrior; /* The setup query */
Select *pFirstRec; /* Left-most recursive term */
int addrTop; /* Top of the loop */
int addrCont, addrBreak; /* CONTINUE and BREAK addresses */
int iCurrent = 0; /* The Current table */
int regCurrent; /* Register holding Current table */
int iQueue; /* The Queue table */
int iDistinct = 0; /* To ensure unique results if UNION */
int eDest = SRT_Fifo; /* How to write to Queue */
SelectDest destQueue; /* SelectDest targetting the Queue table */
int i; /* Loop counter */
int rc; /* Result code */
ExprList *pOrderBy; /* The ORDER BY clause */
Expr *pLimit; /* Saved LIMIT and OFFSET */
int regLimit, regOffset; /* Registers used by LIMIT and OFFSET */
#ifndef SQLITE_OMIT_WINDOWFUNC
if( p->pWin ){
sqlite3ErrorMsg(pParse, "cannot use window functions in recursive queries");
return;
}
#endif
/* Obtain authorization to do a recursive query */
if( sqlite3AuthCheck(pParse, SQLITE_RECURSIVE, 0, 0, 0) ) return;
/* Process the LIMIT and OFFSET clauses, if they exist */
addrBreak = sqlite3VdbeMakeLabel(pParse);
p->nSelectRow = 320; /* 4 billion rows */
computeLimitRegisters(pParse, p, addrBreak);
pLimit = p->pLimit;
regLimit = p->iLimit;
regOffset = p->iOffset;
p->pLimit = 0;
p->iLimit = p->iOffset = 0;
pOrderBy = p->pOrderBy;
/* Locate the cursor number of the Current table */
for(i=0; ALWAYS(i<pSrc->nSrc); i++){
if( pSrc->a[i].fg.isRecursive ){
iCurrent = pSrc->a[i].iCursor;
break;
}
}
/* Allocate cursors numbers for Queue and Distinct. The cursor number for
** the Distinct table must be exactly one greater than Queue in order
** for the SRT_DistFifo and SRT_DistQueue destinations to work. */
iQueue = pParse->nTab++;
if( p->op==TK_UNION ){
eDest = pOrderBy ? SRT_DistQueue : SRT_DistFifo;
iDistinct = pParse->nTab++;
}else{
eDest = pOrderBy ? SRT_Queue : SRT_Fifo;
}
sqlite3SelectDestInit(&destQueue, eDest, iQueue);
/* Allocate cursors for Current, Queue, and Distinct. */
regCurrent = ++pParse->nMem;
sqlite3VdbeAddOp3(v, OP_OpenPseudo, iCurrent, regCurrent, nCol);
if( pOrderBy ){
KeyInfo *pKeyInfo = multiSelectOrderByKeyInfo(pParse, p, 1);
sqlite3VdbeAddOp4(v, OP_OpenEphemeral, iQueue, pOrderBy->nExpr+2, 0,
(char*)pKeyInfo, P4_KEYINFO);
destQueue.pOrderBy = pOrderBy;
}else{
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iQueue, nCol);
}
VdbeComment((v, "Queue table"));
if( iDistinct ){
p->addrOpenEphm[0] = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iDistinct, 0);
p->selFlags |= SF_UsesEphemeral;
}
/* Detach the ORDER BY clause from the compound SELECT */
p->pOrderBy = 0;
/* Figure out how many elements of the compound SELECT are part of the
** recursive query. Make sure no recursive elements use aggregate
** functions. Mark the recursive elements as UNION ALL even if they
** are really UNION because the distinctness will be enforced by the
** iDistinct table. pFirstRec is left pointing to the left-most
** recursive term of the CTE.
*/
pFirstRec = p;
for(pFirstRec=p; ALWAYS(pFirstRec!=0); pFirstRec=pFirstRec->pPrior){
if( pFirstRec->selFlags & SF_Aggregate ){
sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported");
goto end_of_recursive_query;
}
pFirstRec->op = TK_ALL;
if( (pFirstRec->pPrior->selFlags & SF_Recursive)==0 ) break;
}
/* Store the results of the setup-query in Queue. */
pSetup = pFirstRec->pPrior;
pSetup->pNext = 0;
ExplainQueryPlan((pParse, 1, "SETUP"));
rc = sqlite3Select(pParse, pSetup, &destQueue);
pSetup->pNext = p;
if( rc ) goto end_of_recursive_query;
/* Find the next row in the Queue and output that row */
addrTop = sqlite3VdbeAddOp2(v, OP_Rewind, iQueue, addrBreak); VdbeCoverage(v);
/* Transfer the next row in Queue over to Current */
sqlite3VdbeAddOp1(v, OP_NullRow, iCurrent); /* To reset column cache */
if( pOrderBy ){
sqlite3VdbeAddOp3(v, OP_Column, iQueue, pOrderBy->nExpr+1, regCurrent);
}else{
sqlite3VdbeAddOp2(v, OP_RowData, iQueue, regCurrent);
}
sqlite3VdbeAddOp1(v, OP_Delete, iQueue);
/* Output the single row in Current */
addrCont = sqlite3VdbeMakeLabel(pParse);
codeOffset(v, regOffset, addrCont);
selectInnerLoop(pParse, p, iCurrent,
0, 0, pDest, addrCont, addrBreak);
if( regLimit ){
sqlite3VdbeAddOp2(v, OP_DecrJumpZero, regLimit, addrBreak);
VdbeCoverage(v);
}
sqlite3VdbeResolveLabel(v, addrCont);
/* Execute the recursive SELECT taking the single row in Current as
** the value for the recursive-table. Store the results in the Queue.
*/
pFirstRec->pPrior = 0;
ExplainQueryPlan((pParse, 1, "RECURSIVE STEP"));
sqlite3Select(pParse, p, &destQueue);
assert( pFirstRec->pPrior==0 );
pFirstRec->pPrior = pSetup;
/* Keep running the loop until the Queue is empty */
sqlite3VdbeGoto(v, addrTop);
sqlite3VdbeResolveLabel(v, addrBreak);
end_of_recursive_query:
sqlite3ExprListDelete(pParse->db, p->pOrderBy);
p->pOrderBy = pOrderBy;
p->pLimit = pLimit;
return;
}
#endif /* SQLITE_OMIT_CTE */
/* Forward references */
static int multiSelectOrderBy(
Parse *pParse, /* Parsing context */
Select *p, /* The right-most of SELECTs to be coded */
SelectDest *pDest /* What to do with query results */
);
/*
** Handle the special case of a compound-select that originates from a
** VALUES clause. By handling this as a special case, we avoid deep
** recursion, and thus do not need to enforce the SQLITE_LIMIT_COMPOUND_SELECT
** on a VALUES clause.
**
** Because the Select object originates from a VALUES clause:
** (1) There is no LIMIT or OFFSET or else there is a LIMIT of exactly 1
** (2) All terms are UNION ALL
** (3) There is no ORDER BY clause
**
** The "LIMIT of exactly 1" case of condition (1) comes about when a VALUES
** clause occurs within scalar expression (ex: "SELECT (VALUES(1),(2),(3))").
** The sqlite3CodeSubselect will have added the LIMIT 1 clause in tht case.
** Since the limit is exactly 1, we only need to evalutes the left-most VALUES.
*/
static int multiSelectValues(
Parse *pParse, /* Parsing context */
Select *p, /* The right-most of SELECTs to be coded */
SelectDest *pDest /* What to do with query results */
){
int nRow = 1;
int rc = 0;
int bShowAll = p->pLimit==0;
assert( p->selFlags & SF_MultiValue );
do{
assert( p->selFlags & SF_Values );
assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) );
assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr );
#ifndef SQLITE_OMIT_WINDOWFUNC
if( p->pWin ) return -1;
#endif
if( p->pPrior==0 ) break;
assert( p->pPrior->pNext==p );
p = p->pPrior;
nRow += bShowAll;
}while(1);
ExplainQueryPlan((pParse, 0, "SCAN %d CONSTANT ROW%s", nRow,
nRow==1 ? "" : "S"));
while( p ){
selectInnerLoop(pParse, p, -1, 0, 0, pDest, 1, 1);
if( !bShowAll ) break;
p->nSelectRow = nRow;
p = p->pNext;
}
return rc;
}
/*
** Return true if the SELECT statement which is known to be the recursive
** part of a recursive CTE still has its anchor terms attached. If the
** anchor terms have already been removed, then return false.
*/
static int hasAnchor(Select *p){
while( p && (p->selFlags & SF_Recursive)!=0 ){ p = p->pPrior; }
return p!=0;
}
/*
** This routine is called to process a compound query form from
** two or more separate queries using UNION, UNION ALL, EXCEPT, or
** INTERSECT
**
** "p" points to the right-most of the two queries. the query on the
** left is p->pPrior. The left query could also be a compound query
** in which case this routine will be called recursively.
**
** The results of the total query are to be written into a destination
** of type eDest with parameter iParm.
**
** Example 1: Consider a three-way compound SQL statement.
**
** SELECT a FROM t1 UNION SELECT b FROM t2 UNION SELECT c FROM t3
**
** This statement is parsed up as follows:
**
** SELECT c FROM t3
** |
** `-----> SELECT b FROM t2
** |
** `------> SELECT a FROM t1
**
** The arrows in the diagram above represent the Select.pPrior pointer.
** So if this routine is called with p equal to the t3 query, then
** pPrior will be the t2 query. p->op will be TK_UNION in this case.
**
** Notice that because of the way SQLite parses compound SELECTs, the
** individual selects always group from left to right.
*/
static int multiSelect(
Parse *pParse, /* Parsing context */
Select *p, /* The right-most of SELECTs to be coded */
SelectDest *pDest /* What to do with query results */
){
int rc = SQLITE_OK; /* Success code from a subroutine */
Select *pPrior; /* Another SELECT immediately to our left */
Vdbe *v; /* Generate code to this VDBE */
SelectDest dest; /* Alternative data destination */
Select *pDelete = 0; /* Chain of simple selects to delete */
sqlite3 *db; /* Database connection */
/* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs. Only
** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.
*/
assert( p && p->pPrior ); /* Calling function guarantees this much */
assert( (p->selFlags & SF_Recursive)==0 || p->op==TK_ALL || p->op==TK_UNION );
assert( p->selFlags & SF_Compound );
db = pParse->db;
pPrior = p->pPrior;
dest = *pDest;
if( pPrior->pOrderBy || pPrior->pLimit ){
sqlite3ErrorMsg(pParse,"%s clause should come after %s not before",
pPrior->pOrderBy!=0 ? "ORDER BY" : "LIMIT", selectOpName(p->op));
rc = 1;
goto multi_select_end;
}
v = sqlite3GetVdbe(pParse);
assert( v!=0 ); /* The VDBE already created by calling function */
/* Create the destination temporary table if necessary
*/
if( dest.eDest==SRT_EphemTab ){
assert( p->pEList );
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iSDParm, p->pEList->nExpr);
dest.eDest = SRT_Table;
}
/* Special handling for a compound-select that originates as a VALUES clause.
*/
if( p->selFlags & SF_MultiValue ){
rc = multiSelectValues(pParse, p, &dest);
if( rc>=0 ) goto multi_select_end;
rc = SQLITE_OK;
}
/* Make sure all SELECTs in the statement have the same number of elements
** in their result sets.
*/
assert( p->pEList && pPrior->pEList );
assert( p->pEList->nExpr==pPrior->pEList->nExpr );
#ifndef SQLITE_OMIT_CTE
if( (p->selFlags & SF_Recursive)!=0 && hasAnchor(p) ){
generateWithRecursiveQuery(pParse, p, &dest);
}else
#endif
/* Compound SELECTs that have an ORDER BY clause are handled separately.
*/
if( p->pOrderBy ){
return multiSelectOrderBy(pParse, p, pDest);
}else{
#ifndef SQLITE_OMIT_EXPLAIN
if( pPrior->pPrior==0 ){
ExplainQueryPlan((pParse, 1, "COMPOUND QUERY"));
ExplainQueryPlan((pParse, 1, "LEFT-MOST SUBQUERY"));
}
#endif
/* Generate code for the left and right SELECT statements.
*/
switch( p->op ){
case TK_ALL: {
int addr = 0;
int nLimit;
assert( !pPrior->pLimit );
pPrior->iLimit = p->iLimit;
pPrior->iOffset = p->iOffset;
pPrior->pLimit = p->pLimit;
rc = sqlite3Select(pParse, pPrior, &dest);
p->pLimit = 0;
if( rc ){
goto multi_select_end;
}
p->pPrior = 0;
p->iLimit = pPrior->iLimit;
p->iOffset = pPrior->iOffset;
if( p->iLimit ){
addr = sqlite3VdbeAddOp1(v, OP_IfNot, p->iLimit); VdbeCoverage(v);
VdbeComment((v, "Jump ahead if LIMIT reached"));
if( p->iOffset ){
sqlite3VdbeAddOp3(v, OP_OffsetLimit,
p->iLimit, p->iOffset+1, p->iOffset);
}
}
ExplainQueryPlan((pParse, 1, "UNION ALL"));
rc = sqlite3Select(pParse, p, &dest);
testcase( rc!=SQLITE_OK );
pDelete = p->pPrior;
p->pPrior = pPrior;
p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
if( pPrior->pLimit
&& sqlite3ExprIsInteger(pPrior->pLimit->pLeft, &nLimit)
&& nLimit>0 && p->nSelectRow > sqlite3LogEst((u64)nLimit)
){
p->nSelectRow = sqlite3LogEst((u64)nLimit);
}
if( addr ){
sqlite3VdbeJumpHere(v, addr);
}
break;
}
case TK_EXCEPT:
case TK_UNION: {
int unionTab; /* Cursor number of the temp table holding result */
u8 op = 0; /* One of the SRT_ operations to apply to self */
int priorOp; /* The SRT_ operation to apply to prior selects */
Expr *pLimit; /* Saved values of p->nLimit */
int addr;
SelectDest uniondest;
testcase( p->op==TK_EXCEPT );
testcase( p->op==TK_UNION );
priorOp = SRT_Union;
if( dest.eDest==priorOp ){
/* We can reuse a temporary table generated by a SELECT to our
** right.
*/
assert( p->pLimit==0 ); /* Not allowed on leftward elements */
unionTab = dest.iSDParm;
}else{
/* We will need to create our own temporary table to hold the
** intermediate results.
*/
unionTab = pParse->nTab++;
assert( p->pOrderBy==0 );
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0);
assert( p->addrOpenEphm[0] == -1 );
p->addrOpenEphm[0] = addr;
findRightmost(p)->selFlags |= SF_UsesEphemeral;
assert( p->pEList );
}
/* Code the SELECT statements to our left
*/
assert( !pPrior->pOrderBy );
sqlite3SelectDestInit(&uniondest, priorOp, unionTab);
rc = sqlite3Select(pParse, pPrior, &uniondest);
if( rc ){
goto multi_select_end;
}
/* Code the current SELECT statement
*/
if( p->op==TK_EXCEPT ){
op = SRT_Except;
}else{
assert( p->op==TK_UNION );
op = SRT_Union;
}
p->pPrior = 0;
pLimit = p->pLimit;
p->pLimit = 0;
uniondest.eDest = op;
ExplainQueryPlan((pParse, 1, "%s USING TEMP B-TREE",
selectOpName(p->op)));
rc = sqlite3Select(pParse, p, &uniondest);
testcase( rc!=SQLITE_OK );
assert( p->pOrderBy==0 );
pDelete = p->pPrior;
p->pPrior = pPrior;
p->pOrderBy = 0;
if( p->op==TK_UNION ){
p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
}
sqlite3ExprDelete(db, p->pLimit);
p->pLimit = pLimit;
p->iLimit = 0;
p->iOffset = 0;
/* Convert the data in the temporary table into whatever form
** it is that we currently need.
*/
assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
assert( p->pEList || db->mallocFailed );
if( dest.eDest!=priorOp && db->mallocFailed==0 ){
int iCont, iBreak, iStart;
iBreak = sqlite3VdbeMakeLabel(pParse);
iCont = sqlite3VdbeMakeLabel(pParse);
computeLimitRegisters(pParse, p, iBreak);
sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);
iStart = sqlite3VdbeCurrentAddr(v);
selectInnerLoop(pParse, p, unionTab,
0, 0, &dest, iCont, iBreak);
sqlite3VdbeResolveLabel(v, iCont);
sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart); VdbeCoverage(v);
sqlite3VdbeResolveLabel(v, iBreak);
sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);
}
break;
}
default: assert( p->op==TK_INTERSECT ); {
int tab1, tab2;
int iCont, iBreak, iStart;
Expr *pLimit;
int addr;
SelectDest intersectdest;
int r1;
/* INTERSECT is different from the others since it requires
** two temporary tables. Hence it has its own case. Begin
** by allocating the tables we will need.
*/
tab1 = pParse->nTab++;
tab2 = pParse->nTab++;
assert( p->pOrderBy==0 );
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0);
assert( p->addrOpenEphm[0] == -1 );
p->addrOpenEphm[0] = addr;
findRightmost(p)->selFlags |= SF_UsesEphemeral;
assert( p->pEList );
/* Code the SELECTs to our left into temporary table "tab1".
*/
sqlite3SelectDestInit(&intersectdest, SRT_Union, tab1);
rc = sqlite3Select(pParse, pPrior, &intersectdest);
if( rc ){
goto multi_select_end;
}
/* Code the current SELECT into temporary table "tab2"
*/
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);
assert( p->addrOpenEphm[1] == -1 );
p->addrOpenEphm[1] = addr;
p->pPrior = 0;
pLimit = p->pLimit;
p->pLimit = 0;
intersectdest.iSDParm = tab2;
ExplainQueryPlan((pParse, 1, "%s USING TEMP B-TREE",
selectOpName(p->op)));
rc = sqlite3Select(pParse, p, &intersectdest);
testcase( rc!=SQLITE_OK );
pDelete = p->pPrior;
p->pPrior = pPrior;
if( p->nSelectRow>pPrior->nSelectRow ){
p->nSelectRow = pPrior->nSelectRow;
}
sqlite3ExprDelete(db, p->pLimit);
p->pLimit = pLimit;
/* Generate code to take the intersection of the two temporary
** tables.
*/
if( rc ) break;
assert( p->pEList );
iBreak = sqlite3VdbeMakeLabel(pParse);
iCont = sqlite3VdbeMakeLabel(pParse);
computeLimitRegisters(pParse, p, iBreak);
sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
r1 = sqlite3GetTempReg(pParse);
iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1);
sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0);
VdbeCoverage(v);
sqlite3ReleaseTempReg(pParse, r1);
selectInnerLoop(pParse, p, tab1,
0, 0, &dest, iCont, iBreak);
sqlite3VdbeResolveLabel(v, iCont);
sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart); VdbeCoverage(v);
sqlite3VdbeResolveLabel(v, iBreak);
sqlite3VdbeAddOp2(v, OP_Close, tab2, 0);
sqlite3VdbeAddOp2(v, OP_Close, tab1, 0);
break;
}
}
#ifndef SQLITE_OMIT_EXPLAIN
if( p->pNext==0 ){
ExplainQueryPlanPop(pParse);
}
#endif
}
if( pParse->nErr ) goto multi_select_end;
/* Compute collating sequences used by
** temporary tables needed to implement the compound select.
** Attach the KeyInfo structure to all temporary tables.
**
** This section is run by the right-most SELECT statement only.
** SELECT statements to the left always skip this part. The right-most
** SELECT might also skip this part if it has no ORDER BY clause and
** no temp tables are required.
*/
if( p->selFlags & SF_UsesEphemeral ){
int i; /* Loop counter */
KeyInfo *pKeyInfo; /* Collating sequence for the result set */
Select *pLoop; /* For looping through SELECT statements */
CollSeq **apColl; /* For looping through pKeyInfo->aColl[] */
int nCol; /* Number of columns in result set */
assert( p->pNext==0 );
nCol = p->pEList->nExpr;
pKeyInfo = sqlite3KeyInfoAlloc(db, nCol, 1);
if( !pKeyInfo ){
rc = SQLITE_NOMEM_BKPT;
goto multi_select_end;
}
for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
*apColl = multiSelectCollSeq(pParse, p, i);
if( 0==*apColl ){
*apColl = db->pDfltColl;
}
}
for(pLoop=p; pLoop; pLoop=pLoop->pPrior){
for(i=0; i<2; i++){
int addr = pLoop->addrOpenEphm[i];
if( addr<0 ){
/* If [0] is unused then [1] is also unused. So we can
** always safely abort as soon as the first unused slot is found */
assert( pLoop->addrOpenEphm[1]<0 );
break;
}
sqlite3VdbeChangeP2(v, addr, nCol);
sqlite3VdbeChangeP4(v, addr, (char*)sqlite3KeyInfoRef(pKeyInfo),
P4_KEYINFO);
pLoop->addrOpenEphm[i] = -1;
}
}
sqlite3KeyInfoUnref(pKeyInfo);
}
multi_select_end:
pDest->iSdst = dest.iSdst;
pDest->nSdst = dest.nSdst;
sqlite3SelectDelete(db, pDelete);
return rc;
}
#endif /* SQLITE_OMIT_COMPOUND_SELECT */
/*
** Error message for when two or more terms of a compound select have different
** size result sets.
*/
SQLITE_PRIVATE void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p){
if( p->selFlags & SF_Values ){
sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms");
}else{
sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
" do not have the same number of result columns", selectOpName(p->op));
}
}
/*
** Code an output subroutine for a coroutine implementation of a
** SELECT statment.
**
** The data to be output is contained in pIn->iSdst. There are
** pIn->nSdst columns to be output. pDest is where the output should
** be sent.
**
** regReturn is the number of the register holding the subroutine
** return address.
**
** If regPrev>0 then it is the first register in a vector that
** records the previous output. mem[regPrev] is a flag that is false
** if there has been no previous output. If regPrev>0 then code is
** generated to suppress duplicates. pKeyInfo is used for comparing
** keys.
**
** If the LIMIT found in p->iLimit is reached, jump immediately to
** iBreak.
*/
static int generateOutputSubroutine(
Parse *pParse, /* Parsing context */
Select *p, /* The SELECT statement */
SelectDest *pIn, /* Coroutine supplying data */
SelectDest *pDest, /* Where to send the data */
int regReturn, /* The return address register */
int regPrev, /* Previous result register. No uniqueness if 0 */
KeyInfo *pKeyInfo, /* For comparing with previous entry */
int iBreak /* Jump here if we hit the LIMIT */
){
Vdbe *v = pParse->pVdbe;
int iContinue;
int addr;
addr = sqlite3VdbeCurrentAddr(v);
iContinue = sqlite3VdbeMakeLabel(pParse);
/* Suppress duplicates for UNION, EXCEPT, and INTERSECT
*/
if( regPrev ){
int addr1, addr2;
addr1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev); VdbeCoverage(v);
addr2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iSdst, regPrev+1, pIn->nSdst,
(char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
sqlite3VdbeAddOp3(v, OP_Jump, addr2+2, iContinue, addr2+2); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addr1);
sqlite3VdbeAddOp3(v, OP_Copy, pIn->iSdst, regPrev+1, pIn->nSdst-1);
sqlite3VdbeAddOp2(v, OP_Integer, 1, regPrev);
}
if( pParse->db->mallocFailed ) return 0;
/* Suppress the first OFFSET entries if there is an OFFSET clause
*/
codeOffset(v, p->iOffset, iContinue);
assert( pDest->eDest!=SRT_Exists );
assert( pDest->eDest!=SRT_Table );
switch( pDest->eDest ){
/* Store the result as data using a unique key.
*/
case SRT_EphemTab: {
int r1 = sqlite3GetTempReg(pParse);
int r2 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, r1);
sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iSDParm, r2);
sqlite3VdbeAddOp3(v, OP_Insert, pDest->iSDParm, r1, r2);
sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
sqlite3ReleaseTempReg(pParse, r2);
sqlite3ReleaseTempReg(pParse, r1);
break;
}
#ifndef SQLITE_OMIT_SUBQUERY
/* If we are creating a set for an "expr IN (SELECT ...)".
*/
case SRT_Set: {
int r1;
testcase( pIn->nSdst>1 );
r1 = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst,
r1, pDest->zAffSdst, pIn->nSdst);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, pDest->iSDParm, r1,
pIn->iSdst, pIn->nSdst);
sqlite3ReleaseTempReg(pParse, r1);
break;
}
/* If this is a scalar select that is part of an expression, then
** store the results in the appropriate memory cell and break out
** of the scan loop. Note that the select might return multiple columns
** if it is the RHS of a row-value IN operator.
*/
case SRT_Mem: {
if( pParse->nErr==0 ){
testcase( pIn->nSdst>1 );
sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSDParm, pIn->nSdst);
}
/* The LIMIT clause will jump out of the loop for us */
break;
}
#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
/* The results are stored in a sequence of registers
** starting at pDest->iSdst. Then the co-routine yields.
*/
case SRT_Coroutine: {
if( pDest->iSdst==0 ){
pDest->iSdst = sqlite3GetTempRange(pParse, pIn->nSdst);
pDest->nSdst = pIn->nSdst;
}
sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pIn->nSdst);
sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm);
break;
}
/* If none of the above, then the result destination must be
** SRT_Output. This routine is never called with any other
** destination other than the ones handled above or SRT_Output.
**
** For SRT_Output, results are stored in a sequence of registers.
** Then the OP_ResultRow opcode is used to cause sqlite3_step() to
** return the next row of result.
*/
default: {
assert( pDest->eDest==SRT_Output );
sqlite3VdbeAddOp2(v, OP_ResultRow, pIn->iSdst, pIn->nSdst);
break;
}
}
/* Jump to the end of the loop if the LIMIT is reached.
*/
if( p->iLimit ){
sqlite3VdbeAddOp2(v, OP_DecrJumpZero, p->iLimit, iBreak); VdbeCoverage(v);
}
/* Generate the subroutine return
*/
sqlite3VdbeResolveLabel(v, iContinue);
sqlite3VdbeAddOp1(v, OP_Return, regReturn);
return addr;
}
/*
** Alternative compound select code generator for cases when there
** is an ORDER BY clause.
**
** We assume a query of the following form:
**
** <selectA> <operator> <selectB> ORDER BY <orderbylist>
**
** <operator> is one of UNION ALL, UNION, EXCEPT, or INTERSECT. The idea
** is to code both <selectA> and <selectB> with the ORDER BY clause as
** co-routines. Then run the co-routines in parallel and merge the results
** into the output. In addition to the two coroutines (called selectA and
** selectB) there are 7 subroutines:
**
** outA: Move the output of the selectA coroutine into the output
** of the compound query.
**
** outB: Move the output of the selectB coroutine into the output
** of the compound query. (Only generated for UNION and
** UNION ALL. EXCEPT and INSERTSECT never output a row that
** appears only in B.)
**
** AltB: Called when there is data from both coroutines and A<B.
**
** AeqB: Called when there is data from both coroutines and A==B.
**
** AgtB: Called when there is data from both coroutines and A>B.
**
** EofA: Called when data is exhausted from selectA.
**
** EofB: Called when data is exhausted from selectB.
**
** The implementation of the latter five subroutines depend on which
** <operator> is used:
**
**
** UNION ALL UNION EXCEPT INTERSECT
** ------------- ----------------- -------------- -----------------
** AltB: outA, nextA outA, nextA outA, nextA nextA
**
** AeqB: outA, nextA nextA nextA outA, nextA
**
** AgtB: outB, nextB outB, nextB nextB nextB
**
** EofA: outB, nextB outB, nextB halt halt
**
** EofB: outA, nextA outA, nextA outA, nextA halt
**
** In the AltB, AeqB, and AgtB subroutines, an EOF on A following nextA
** causes an immediate jump to EofA and an EOF on B following nextB causes
** an immediate jump to EofB. Within EofA and EofB, and EOF on entry or
** following nextX causes a jump to the end of the select processing.
**
** Duplicate removal in the UNION, EXCEPT, and INTERSECT cases is handled
** within the output subroutine. The regPrev register set holds the previously
** output value. A comparison is made against this value and the output
** is skipped if the next results would be the same as the previous.
**
** The implementation plan is to implement the two coroutines and seven
** subroutines first, then put the control logic at the bottom. Like this:
**
** goto Init
** coA: coroutine for left query (A)
** coB: coroutine for right query (B)
** outA: output one row of A
** outB: output one row of B (UNION and UNION ALL only)
** EofA: ...
** EofB: ...
** AltB: ...
** AeqB: ...
** AgtB: ...
** Init: initialize coroutine registers
** yield coA
** if eof(A) goto EofA
** yield coB
** if eof(B) goto EofB
** Cmpr: Compare A, B
** Jump AltB, AeqB, AgtB
** End: ...
**
** We call AltB, AeqB, AgtB, EofA, and EofB "subroutines" but they are not
** actually called using Gosub and they do not Return. EofA and EofB loop
** until all data is exhausted then jump to the "end" labe. AltB, AeqB,
** and AgtB jump to either L2 or to one of EofA or EofB.
*/
#ifndef SQLITE_OMIT_COMPOUND_SELECT
static int multiSelectOrderBy(
Parse *pParse, /* Parsing context */
Select *p, /* The right-most of SELECTs to be coded */
SelectDest *pDest /* What to do with query results */
){
int i, j; /* Loop counters */
Select *pPrior; /* Another SELECT immediately to our left */
Vdbe *v; /* Generate code to this VDBE */
SelectDest destA; /* Destination for coroutine A */
SelectDest destB; /* Destination for coroutine B */
int regAddrA; /* Address register for select-A coroutine */
int regAddrB; /* Address register for select-B coroutine */
int addrSelectA; /* Address of the select-A coroutine */
int addrSelectB; /* Address of the select-B coroutine */
int regOutA; /* Address register for the output-A subroutine */
int regOutB; /* Address register for the output-B subroutine */
int addrOutA; /* Address of the output-A subroutine */
int addrOutB = 0; /* Address of the output-B subroutine */
int addrEofA; /* Address of the select-A-exhausted subroutine */
int addrEofA_noB; /* Alternate addrEofA if B is uninitialized */
int addrEofB; /* Address of the select-B-exhausted subroutine */
int addrAltB; /* Address of the A<B subroutine */
int addrAeqB; /* Address of the A==B subroutine */
int addrAgtB; /* Address of the A>B subroutine */
int regLimitA; /* Limit register for select-A */
int regLimitB; /* Limit register for select-A */
int regPrev; /* A range of registers to hold previous output */
int savedLimit; /* Saved value of p->iLimit */
int savedOffset; /* Saved value of p->iOffset */
int labelCmpr; /* Label for the start of the merge algorithm */
int labelEnd; /* Label for the end of the overall SELECT stmt */
int addr1; /* Jump instructions that get retargetted */
int op; /* One of TK_ALL, TK_UNION, TK_EXCEPT, TK_INTERSECT */
KeyInfo *pKeyDup = 0; /* Comparison information for duplicate removal */
KeyInfo *pKeyMerge; /* Comparison information for merging rows */
sqlite3 *db; /* Database connection */
ExprList *pOrderBy; /* The ORDER BY clause */
int nOrderBy; /* Number of terms in the ORDER BY clause */
u32 *aPermute; /* Mapping from ORDER BY terms to result set columns */
assert( p->pOrderBy!=0 );
assert( pKeyDup==0 ); /* "Managed" code needs this. Ticket #3382. */
db = pParse->db;
v = pParse->pVdbe;
assert( v!=0 ); /* Already thrown the error if VDBE alloc failed */
labelEnd = sqlite3VdbeMakeLabel(pParse);
labelCmpr = sqlite3VdbeMakeLabel(pParse);
/* Patch up the ORDER BY clause
*/
op = p->op;
pPrior = p->pPrior;
assert( pPrior->pOrderBy==0 );
pOrderBy = p->pOrderBy;
assert( pOrderBy );
nOrderBy = pOrderBy->nExpr;
/* For operators other than UNION ALL we have to make sure that
** the ORDER BY clause covers every term of the result set. Add
** terms to the ORDER BY clause as necessary.
*/
if( op!=TK_ALL ){
for(i=1; db->mallocFailed==0 && i<=p->pEList->nExpr; i++){
struct ExprList_item *pItem;
for(j=0, pItem=pOrderBy->a; j<nOrderBy; j++, pItem++){
assert( pItem->u.x.iOrderByCol>0 );
if( pItem->u.x.iOrderByCol==i ) break;
}
if( j==nOrderBy ){
Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0);
if( pNew==0 ) return SQLITE_NOMEM_BKPT;
pNew->flags |= EP_IntValue;
pNew->u.iValue = i;
p->pOrderBy = pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew);
if( pOrderBy ) pOrderBy->a[nOrderBy++].u.x.iOrderByCol = (u16)i;
}
}
}
/* Compute the comparison permutation and keyinfo that is used with
** the permutation used to determine if the next
** row of results comes from selectA or selectB. Also add explicit
** collations to the ORDER BY clause terms so that when the subqueries
** to the right and the left are evaluated, they use the correct
** collation.
*/
aPermute = sqlite3DbMallocRawNN(db, sizeof(u32)*(nOrderBy + 1));
if( aPermute ){
struct ExprList_item *pItem;
aPermute[0] = nOrderBy;
for(i=1, pItem=pOrderBy->a; i<=nOrderBy; i++, pItem++){
assert( pItem->u.x.iOrderByCol>0 );
assert( pItem->u.x.iOrderByCol<=p->pEList->nExpr );
aPermute[i] = pItem->u.x.iOrderByCol - 1;
}
pKeyMerge = multiSelectOrderByKeyInfo(pParse, p, 1);
}else{
pKeyMerge = 0;
}
/* Reattach the ORDER BY clause to the query.
*/
p->pOrderBy = pOrderBy;
pPrior->pOrderBy = sqlite3ExprListDup(pParse->db, pOrderBy, 0);
/* Allocate a range of temporary registers and the KeyInfo needed
** for the logic that removes duplicate result rows when the
** operator is UNION, EXCEPT, or INTERSECT (but not UNION ALL).
*/
if( op==TK_ALL ){
regPrev = 0;
}else{
int nExpr = p->pEList->nExpr;
assert( nOrderBy>=nExpr || db->mallocFailed );
regPrev = pParse->nMem+1;
pParse->nMem += nExpr+1;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev);
pKeyDup = sqlite3KeyInfoAlloc(db, nExpr, 1);
if( pKeyDup ){
assert( sqlite3KeyInfoIsWriteable(pKeyDup) );
for(i=0; i<nExpr; i++){
pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i);
pKeyDup->aSortFlags[i] = 0;
}
}
}
/* Separate the left and the right query from one another
*/
p->pPrior = 0;
pPrior->pNext = 0;
sqlite3ResolveOrderGroupBy(pParse, p, p->pOrderBy, "ORDER");
if( pPrior->pPrior==0 ){
sqlite3ResolveOrderGroupBy(pParse, pPrior, pPrior->pOrderBy, "ORDER");
}
/* Compute the limit registers */
computeLimitRegisters(pParse, p, labelEnd);
if( p->iLimit && op==TK_ALL ){
regLimitA = ++pParse->nMem;
regLimitB = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Copy, p->iOffset ? p->iOffset+1 : p->iLimit,
regLimitA);
sqlite3VdbeAddOp2(v, OP_Copy, regLimitA, regLimitB);
}else{
regLimitA = regLimitB = 0;
}
sqlite3ExprDelete(db, p->pLimit);
p->pLimit = 0;
regAddrA = ++pParse->nMem;
regAddrB = ++pParse->nMem;
regOutA = ++pParse->nMem;
regOutB = ++pParse->nMem;
sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA);
sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB);
ExplainQueryPlan((pParse, 1, "MERGE (%s)", selectOpName(p->op)));
/* Generate a coroutine to evaluate the SELECT statement to the
** left of the compound operator - the "A" select.
*/
addrSelectA = sqlite3VdbeCurrentAddr(v) + 1;
addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrA, 0, addrSelectA);
VdbeComment((v, "left SELECT"));
pPrior->iLimit = regLimitA;
ExplainQueryPlan((pParse, 1, "LEFT"));
sqlite3Select(pParse, pPrior, &destA);
sqlite3VdbeEndCoroutine(v, regAddrA);
sqlite3VdbeJumpHere(v, addr1);
/* Generate a coroutine to evaluate the SELECT statement on
** the right - the "B" select
*/
addrSelectB = sqlite3VdbeCurrentAddr(v) + 1;
addr1 = sqlite3VdbeAddOp3(v, OP_InitCoroutine, regAddrB, 0, addrSelectB);
VdbeComment((v, "right SELECT"));
savedLimit = p->iLimit;
savedOffset = p->iOffset;
p->iLimit = regLimitB;
p->iOffset = 0;
ExplainQueryPlan((pParse, 1, "RIGHT"));
sqlite3Select(pParse, p, &destB);
p->iLimit = savedLimit;
p->iOffset = savedOffset;
sqlite3VdbeEndCoroutine(v, regAddrB);
/* Generate a subroutine that outputs the current row of the A
** select as the next output row of the compound select.
*/
VdbeNoopComment((v, "Output routine for A"));
addrOutA = generateOutputSubroutine(pParse,
p, &destA, pDest, regOutA,
regPrev, pKeyDup, labelEnd);
/* Generate a subroutine that outputs the current row of the B
** select as the next output row of the compound select.
*/
if( op==TK_ALL || op==TK_UNION ){
VdbeNoopComment((v, "Output routine for B"));
addrOutB = generateOutputSubroutine(pParse,
p, &destB, pDest, regOutB,
regPrev, pKeyDup, labelEnd);
}
sqlite3KeyInfoUnref(pKeyDup);
/* Generate a subroutine to run when the results from select A
** are exhausted and only data in select B remains.
*/
if( op==TK_EXCEPT || op==TK_INTERSECT ){
addrEofA_noB = addrEofA = labelEnd;
}else{
VdbeNoopComment((v, "eof-A subroutine"));
addrEofA = sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
addrEofA_noB = sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, labelEnd);
VdbeCoverage(v);
sqlite3VdbeGoto(v, addrEofA);
p->nSelectRow = sqlite3LogEstAdd(p->nSelectRow, pPrior->nSelectRow);
}
/* Generate a subroutine to run when the results from select B
** are exhausted and only data in select A remains.
*/
if( op==TK_INTERSECT ){
addrEofB = addrEofA;
if( p->nSelectRow > pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow;
}else{
VdbeNoopComment((v, "eof-B subroutine"));
addrEofB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, labelEnd); VdbeCoverage(v);
sqlite3VdbeGoto(v, addrEofB);
}
/* Generate code to handle the case of A<B
*/
VdbeNoopComment((v, "A-lt-B subroutine"));
addrAltB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);
sqlite3VdbeGoto(v, labelCmpr);
/* Generate code to handle the case of A==B
*/
if( op==TK_ALL ){
addrAeqB = addrAltB;
}else if( op==TK_INTERSECT ){
addrAeqB = addrAltB;
addrAltB++;
}else{
VdbeNoopComment((v, "A-eq-B subroutine"));
addrAeqB =
sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA); VdbeCoverage(v);
sqlite3VdbeGoto(v, labelCmpr);
}
/* Generate code to handle the case of A>B
*/
VdbeNoopComment((v, "A-gt-B subroutine"));
addrAgtB = sqlite3VdbeCurrentAddr(v);
if( op==TK_ALL || op==TK_UNION ){
sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
}
sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
sqlite3VdbeGoto(v, labelCmpr);
/* This code runs once to initialize everything.
*/
sqlite3VdbeJumpHere(v, addr1);
sqlite3VdbeAddOp2(v, OP_Yield, regAddrA, addrEofA_noB); VdbeCoverage(v);
sqlite3VdbeAddOp2(v, OP_Yield, regAddrB, addrEofB); VdbeCoverage(v);
/* Implement the main merge loop
*/
sqlite3VdbeResolveLabel(v, labelCmpr);
sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY);
sqlite3VdbeAddOp4(v, OP_Compare, destA.iSdst, destB.iSdst, nOrderBy,
(char*)pKeyMerge, P4_KEYINFO);
sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v);
/* Jump to the this point in order to terminate the query.
*/
sqlite3VdbeResolveLabel(v, labelEnd);
/* Reassembly the compound query so that it will be freed correctly
** by the calling function */
if( p->pPrior ){
sqlite3SelectDelete(db, p->pPrior);
}
p->pPrior = pPrior;
pPrior->pNext = p;
/*** TBD: Insert subroutine calls to close cursors on incomplete
**** subqueries ****/
ExplainQueryPlanPop(pParse);
return pParse->nErr!=0;
}
#endif
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
/* An instance of the SubstContext object describes an substitution edit
** to be performed on a parse tree.
**
** All references to columns in table iTable are to be replaced by corresponding
** expressions in pEList.
*/
typedef struct SubstContext {
Parse *pParse; /* The parsing context */
int iTable; /* Replace references to this table */
int iNewTable; /* New table number */
int isLeftJoin; /* Add TK_IF_NULL_ROW opcodes on each replacement */
ExprList *pEList; /* Replacement expressions */
} SubstContext;
/* Forward Declarations */
static void substExprList(SubstContext*, ExprList*);
static void substSelect(SubstContext*, Select*, int);
/*
** Scan through the expression pExpr. Replace every reference to
** a column in table number iTable with a copy of the iColumn-th
** entry in pEList. (But leave references to the ROWID column
** unchanged.)
**
** This routine is part of the flattening procedure. A subquery
** whose result set is defined by pEList appears as entry in the
** FROM clause of a SELECT such that the VDBE cursor assigned to that
** FORM clause entry is iTable. This routine makes the necessary
** changes to pExpr so that it refers directly to the source table
** of the subquery rather the result set of the subquery.
*/
static Expr *substExpr(
SubstContext *pSubst, /* Description of the substitution */
Expr *pExpr /* Expr in which substitution occurs */
){
if( pExpr==0 ) return 0;
if( ExprHasProperty(pExpr, EP_FromJoin)
&& pExpr->iRightJoinTable==pSubst->iTable
){
pExpr->iRightJoinTable = pSubst->iNewTable;
}
if( pExpr->op==TK_COLUMN
&& pExpr->iTable==pSubst->iTable
&& !ExprHasProperty(pExpr, EP_FixedCol)
){
if( pExpr->iColumn<0 ){
pExpr->op = TK_NULL;
}else{
Expr *pNew;
Expr *pCopy = pSubst->pEList->a[pExpr->iColumn].pExpr;
Expr ifNullRow;
assert( pSubst->pEList!=0 && pExpr->iColumn<pSubst->pEList->nExpr );
assert( pExpr->pRight==0 );
if( sqlite3ExprIsVector(pCopy) ){
sqlite3VectorErrorMsg(pSubst->pParse, pCopy);
}else{
sqlite3 *db = pSubst->pParse->db;
if( pSubst->isLeftJoin && pCopy->op!=TK_COLUMN ){
memset(&ifNullRow, 0, sizeof(ifNullRow));
ifNullRow.op = TK_IF_NULL_ROW;
ifNullRow.pLeft = pCopy;
ifNullRow.iTable = pSubst->iNewTable;
ifNullRow.flags = EP_IfNullRow;
pCopy = &ifNullRow;
}
testcase( ExprHasProperty(pCopy, EP_Subquery) );
pNew = sqlite3ExprDup(db, pCopy, 0);
if( pNew && pSubst->isLeftJoin ){
ExprSetProperty(pNew, EP_CanBeNull);
}
if( pNew && ExprHasProperty(pExpr,EP_FromJoin) ){
sqlite3SetJoinExpr(pNew, pExpr->iRightJoinTable);
}
sqlite3ExprDelete(db, pExpr);
pExpr = pNew;
/* Ensure that the expression now has an implicit collation sequence,
** just as it did when it was a column of a view or sub-query. */
if( pExpr ){
if( pExpr->op!=TK_COLUMN && pExpr->op!=TK_COLLATE ){
CollSeq *pColl = sqlite3ExprCollSeq(pSubst->pParse, pExpr);
pExpr = sqlite3ExprAddCollateString(pSubst->pParse, pExpr,
(pColl ? pColl->zName : "BINARY")
);
}
ExprClearProperty(pExpr, EP_Collate);
}
}
}
}else{
if( pExpr->op==TK_IF_NULL_ROW && pExpr->iTable==pSubst->iTable ){
pExpr->iTable = pSubst->iNewTable;
}
pExpr->pLeft = substExpr(pSubst, pExpr->pLeft);
pExpr->pRight = substExpr(pSubst, pExpr->pRight);
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
substSelect(pSubst, pExpr->x.pSelect, 1);
}else{
substExprList(pSubst, pExpr->x.pList);
}
#ifndef SQLITE_OMIT_WINDOWFUNC
if( ExprHasProperty(pExpr, EP_WinFunc) ){
Window *pWin = pExpr->y.pWin;
pWin->pFilter = substExpr(pSubst, pWin->pFilter);
substExprList(pSubst, pWin->pPartition);
substExprList(pSubst, pWin->pOrderBy);
}
#endif
}
return pExpr;
}
static void substExprList(
SubstContext *pSubst, /* Description of the substitution */
ExprList *pList /* List to scan and in which to make substitutes */
){
int i;
if( pList==0 ) return;
for(i=0; i<pList->nExpr; i++){
pList->a[i].pExpr = substExpr(pSubst, pList->a[i].pExpr);
}
}
static void substSelect(
SubstContext *pSubst, /* Description of the substitution */
Select *p, /* SELECT statement in which to make substitutions */
int doPrior /* Do substitutes on p->pPrior too */
){
SrcList *pSrc;
struct SrcList_item *pItem;
int i;
if( !p ) return;
do{
substExprList(pSubst, p->pEList);
substExprList(pSubst, p->pGroupBy);
substExprList(pSubst, p->pOrderBy);
p->pHaving = substExpr(pSubst, p->pHaving);
p->pWhere = substExpr(pSubst, p->pWhere);
pSrc = p->pSrc;
assert( pSrc!=0 );
for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
substSelect(pSubst, pItem->pSelect, 1);
if( pItem->fg.isTabFunc ){
substExprList(pSubst, pItem->u1.pFuncArg);
}
}
}while( doPrior && (p = p->pPrior)!=0 );
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
/*
** pSelect is a SELECT statement and pSrcItem is one item in the FROM
** clause of that SELECT.
**
** This routine scans the entire SELECT statement and recomputes the
** pSrcItem->colUsed mask.
*/
static int recomputeColumnsUsedExpr(Walker *pWalker, Expr *pExpr){
struct SrcList_item *pItem;
if( pExpr->op!=TK_COLUMN ) return WRC_Continue;
pItem = pWalker->u.pSrcItem;
if( pItem->iCursor!=pExpr->iTable ) return WRC_Continue;
if( pExpr->iColumn<0 ) return WRC_Continue;
pItem->colUsed |= sqlite3ExprColUsed(pExpr);
return WRC_Continue;
}
static void recomputeColumnsUsed(
Select *pSelect, /* The complete SELECT statement */
struct SrcList_item *pSrcItem /* Which FROM clause item to recompute */
){
Walker w;
if( NEVER(pSrcItem->pTab==0) ) return;
memset(&w, 0, sizeof(w));
w.xExprCallback = recomputeColumnsUsedExpr;
w.xSelectCallback = sqlite3SelectWalkNoop;
w.u.pSrcItem = pSrcItem;
pSrcItem->colUsed = 0;
sqlite3WalkSelect(&w, pSelect);
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
/*
** This routine attempts to flatten subqueries as a performance optimization.
** This routine returns 1 if it makes changes and 0 if no flattening occurs.
**
** To understand the concept of flattening, consider the following
** query:
**
** SELECT a FROM (SELECT x+y AS a FROM t1 WHERE z<100) WHERE a>5
**
** The default way of implementing this query is to execute the
** subquery first and store the results in a temporary table, then
** run the outer query on that temporary table. This requires two
** passes over the data. Furthermore, because the temporary table
** has no indices, the WHERE clause on the outer query cannot be
** optimized.
**
** This routine attempts to rewrite queries such as the above into
** a single flat select, like this:
**
** SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
**
** The code generated for this simplification gives the same result
** but only has to scan the data once. And because indices might
** exist on the table t1, a complete scan of the data might be
** avoided.
**
** Flattening is subject to the following constraints:
**
** (**) We no longer attempt to flatten aggregate subqueries. Was:
** The subquery and the outer query cannot both be aggregates.
**
** (**) We no longer attempt to flatten aggregate subqueries. Was:
** (2) If the subquery is an aggregate then
** (2a) the outer query must not be a join and
** (2b) the outer query must not use subqueries
** other than the one FROM-clause subquery that is a candidate
** for flattening. (This is due to ticket [2f7170d73bf9abf80]
** from 2015-02-09.)
**
** (3) If the subquery is the right operand of a LEFT JOIN then
** (3a) the subquery may not be a join and
** (3b) the FROM clause of the subquery may not contain a virtual
** table and
** (3c) the outer query may not be an aggregate.
** (3d) the outer query may not be DISTINCT.
**
** (4) The subquery can not be DISTINCT.
**
** (**) At one point restrictions (4) and (5) defined a subset of DISTINCT
** sub-queries that were excluded from this optimization. Restriction
** (4) has since been expanded to exclude all DISTINCT subqueries.
**
** (**) We no longer attempt to flatten aggregate subqueries. Was:
** If the subquery is aggregate, the outer query may not be DISTINCT.
**
** (7) The subquery must have a FROM clause. TODO: For subqueries without
** A FROM clause, consider adding a FROM clause with the special
** table sqlite_once that consists of a single row containing a
** single NULL.
**
** (8) If the subquery uses LIMIT then the outer query may not be a join.
**
** (9) If the subquery uses LIMIT then the outer query may not be aggregate.
**
** (**) Restriction (10) was removed from the code on 2005-02-05 but we
** accidently carried the comment forward until 2014-09-15. Original
** constraint: "If the subquery is aggregate then the outer query
** may not use LIMIT."
**
** (11) The subquery and the outer query may not both have ORDER BY clauses.
**
** (**) Not implemented. Subsumed into restriction (3). Was previously
** a separate restriction deriving from ticket #350.
**
** (13) The subquery and outer query may not both use LIMIT.
**
** (14) The subquery may not use OFFSET.
**
** (15) If the outer query is part of a compound select, then the
** subquery may not use LIMIT.
** (See ticket #2339 and ticket [02a8e81d44]).
**
** (16) If the outer query is aggregate, then the subquery may not
** use ORDER BY. (Ticket #2942) This used to not matter
** until we introduced the group_concat() function.
**
** (17) If the subquery is a compound select, then
** (17a) all compound operators must be a UNION ALL, and
** (17b) no terms within the subquery compound may be aggregate
** or DISTINCT, and
** (17c) every term within the subquery compound must have a FROM clause
** (17d) the outer query may not be
** (17d1) aggregate, or
** (17d2) DISTINCT, or
** (17d3) a join.
** (17e) the subquery may not contain window functions
**
** The parent and sub-query may contain WHERE clauses. Subject to
** rules (11), (13) and (14), they may also contain ORDER BY,
** LIMIT and OFFSET clauses. The subquery cannot use any compound
** operator other than UNION ALL because all the other compound
** operators have an implied DISTINCT which is disallowed by
** restriction (4).
**
** Also, each component of the sub-query must return the same number
** of result columns. This is actually a requirement for any compound
** SELECT statement, but all the code here does is make sure that no
** such (illegal) sub-query is flattened. The caller will detect the
** syntax error and return a detailed message.
**
** (18) If the sub-query is a compound select, then all terms of the
** ORDER BY clause of the parent must be simple references to
** columns of the sub-query.
**
** (19) If the subquery uses LIMIT then the outer query may not
** have a WHERE clause.
**
** (20) If the sub-query is a compound select, then it must not use
** an ORDER BY clause. Ticket #3773. We could relax this constraint
** somewhat by saying that the terms of the ORDER BY clause must
** appear as unmodified result columns in the outer query. But we
** have other optimizations in mind to deal with that case.
**
** (21) If the subquery uses LIMIT then the outer query may not be
** DISTINCT. (See ticket [752e1646fc]).
**
** (22) The subquery may not be a recursive CTE.
**
** (**) Subsumed into restriction (17d3). Was: If the outer query is
** a recursive CTE, then the sub-query may not be a compound query.
** This restriction is because transforming the
** parent to a compound query confuses the code that handles
** recursive queries in multiSelect().
**
** (**) We no longer attempt to flatten aggregate subqueries. Was:
** The subquery may not be an aggregate that uses the built-in min() or
** or max() functions. (Without this restriction, a query like:
** "SELECT x FROM (SELECT max(y), x FROM t1)" would not necessarily
** return the value X for which Y was maximal.)
**
** (25) If either the subquery or the parent query contains a window
** function in the select list or ORDER BY clause, flattening
** is not attempted.
**
**
** In this routine, the "p" parameter is a pointer to the outer query.
** The subquery is p->pSrc->a[iFrom]. isAgg is true if the outer query
** uses aggregates.
**
** If flattening is not attempted, this routine is a no-op and returns 0.
** If flattening is attempted this routine returns 1.
**
** All of the expression analysis must occur on both the outer query and
** the subquery before this routine runs.
*/
static int flattenSubquery(
Parse *pParse, /* Parsing context */
Select *p, /* The parent or outer SELECT statement */
int iFrom, /* Index in p->pSrc->a[] of the inner subquery */
int isAgg /* True if outer SELECT uses aggregate functions */
){
const char *zSavedAuthContext = pParse->zAuthContext;
Select *pParent; /* Current UNION ALL term of the other query */
Select *pSub; /* The inner query or "subquery" */
Select *pSub1; /* Pointer to the rightmost select in sub-query */
SrcList *pSrc; /* The FROM clause of the outer query */
SrcList *pSubSrc; /* The FROM clause of the subquery */
int iParent; /* VDBE cursor number of the pSub result set temp table */
int iNewParent = -1;/* Replacement table for iParent */
int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */
int i; /* Loop counter */
Expr *pWhere; /* The WHERE clause */
struct SrcList_item *pSubitem; /* The subquery */
sqlite3 *db = pParse->db;
Walker w; /* Walker to persist agginfo data */
/* Check to see if flattening is permitted. Return 0 if not.
*/
assert( p!=0 );
assert( p->pPrior==0 );
if( OptimizationDisabled(db, SQLITE_QueryFlattener) ) return 0;
pSrc = p->pSrc;
assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
pSubitem = &pSrc->a[iFrom];
iParent = pSubitem->iCursor;
pSub = pSubitem->pSelect;
assert( pSub!=0 );
#ifndef SQLITE_OMIT_WINDOWFUNC
if( p->pWin || pSub->pWin ) return 0; /* Restriction (25) */
#endif
pSubSrc = pSub->pSrc;
assert( pSubSrc );
/* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
** not arbitrary expressions, we allowed some combining of LIMIT and OFFSET
** because they could be computed at compile-time. But when LIMIT and OFFSET
** became arbitrary expressions, we were forced to add restrictions (13)
** and (14). */
if( pSub->pLimit && p->pLimit ) return 0; /* Restriction (13) */
if( pSub->pLimit && pSub->pLimit->pRight ) return 0; /* Restriction (14) */
if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
return 0; /* Restriction (15) */
}
if( pSubSrc->nSrc==0 ) return 0; /* Restriction (7) */
if( pSub->selFlags & SF_Distinct ) return 0; /* Restriction (4) */
if( pSub->pLimit && (pSrc->nSrc>1 || isAgg) ){
return 0; /* Restrictions (8)(9) */
}
if( p->pOrderBy && pSub->pOrderBy ){
return 0; /* Restriction (11) */
}
if( isAgg && pSub->pOrderBy ) return 0; /* Restriction (16) */
if( pSub->pLimit && p->pWhere ) return 0; /* Restriction (19) */
if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){
return 0; /* Restriction (21) */
}
if( pSub->selFlags & (SF_Recursive) ){
return 0; /* Restrictions (22) */
}
/*
** If the subquery is the right operand of a LEFT JOIN, then the
** subquery may not be a join itself (3a). Example of why this is not
** allowed:
**
** t1 LEFT OUTER JOIN (t2 JOIN t3)
**
** If we flatten the above, we would get
**
** (t1 LEFT OUTER JOIN t2) JOIN t3
**
** which is not at all the same thing.
**
** If the subquery is the right operand of a LEFT JOIN, then the outer
** query cannot be an aggregate. (3c) This is an artifact of the way
** aggregates are processed - there is no mechanism to determine if
** the LEFT JOIN table should be all-NULL.
**
** See also tickets #306, #350, and #3300.
*/
if( (pSubitem->fg.jointype & JT_OUTER)!=0 ){
isLeftJoin = 1;
if( pSubSrc->nSrc>1 /* (3a) */
|| isAgg /* (3b) */
|| IsVirtual(pSubSrc->a[0].pTab) /* (3c) */
|| (p->selFlags & SF_Distinct)!=0 /* (3d) */
){
return 0;
}
}
#ifdef SQLITE_EXTRA_IFNULLROW
else if( iFrom>0 && !isAgg ){
/* Setting isLeftJoin to -1 causes OP_IfNullRow opcodes to be generated for
** every reference to any result column from subquery in a join, even
** though they are not necessary. This will stress-test the OP_IfNullRow
** opcode. */
isLeftJoin = -1;
}
#endif
/* Restriction (17): If the sub-query is a compound SELECT, then it must
** use only the UNION ALL operator. And none of the simple select queries
** that make up the compound SELECT are allowed to be aggregate or distinct
** queries.
*/
if( pSub->pPrior ){
if( pSub->pOrderBy ){
return 0; /* Restriction (20) */
}
if( isAgg || (p->selFlags & SF_Distinct)!=0 || pSrc->nSrc!=1 ){
return 0; /* (17d1), (17d2), or (17d3) */
}
for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){
testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct );
testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate );
assert( pSub->pSrc!=0 );
assert( pSub->pEList->nExpr==pSub1->pEList->nExpr );
if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0 /* (17b) */
|| (pSub1->pPrior && pSub1->op!=TK_ALL) /* (17a) */
|| pSub1->pSrc->nSrc<1 /* (17c) */
#ifndef SQLITE_OMIT_WINDOWFUNC
|| pSub1->pWin /* (17e) */
#endif
){
return 0;
}
testcase( pSub1->pSrc->nSrc>1 );
}
/* Restriction (18). */
if( p->pOrderBy ){
int ii;
for(ii=0; ii<p->pOrderBy->nExpr; ii++){
if( p->pOrderBy->a[ii].u.x.iOrderByCol==0 ) return 0;
}
}
}
/* Ex-restriction (23):
** The only way that the recursive part of a CTE can contain a compound
** subquery is for the subquery to be one term of a join. But if the
** subquery is a join, then the flattening has already been stopped by
** restriction (17d3)
*/
assert( (p->selFlags & SF_Recursive)==0 || pSub->pPrior==0 );
/***** If we reach this point, flattening is permitted. *****/
SELECTTRACE(1,pParse,p,("flatten %u.%p from term %d\n",
pSub->selId, pSub, iFrom));
/* Authorize the subquery */
pParse->zAuthContext = pSubitem->zName;
TESTONLY(i =) sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0);
testcase( i==SQLITE_DENY );
pParse->zAuthContext = zSavedAuthContext;
/* If the sub-query is a compound SELECT statement, then (by restrictions
** 17 and 18 above) it must be a UNION ALL and the parent query must
** be of the form:
**
** SELECT <expr-list> FROM (<sub-query>) <where-clause>
**
** followed by any ORDER BY, LIMIT and/or OFFSET clauses. This block
** creates N-1 copies of the parent query without any ORDER BY, LIMIT or
** OFFSET clauses and joins them to the left-hand-side of the original
** using UNION ALL operators. In this case N is the number of simple
** select statements in the compound sub-query.
**
** Example:
**
** SELECT a+1 FROM (
** SELECT x FROM tab
** UNION ALL
** SELECT y FROM tab
** UNION ALL
** SELECT abs(z*2) FROM tab2
** ) WHERE a!=5 ORDER BY 1
**
** Transformed into:
**
** SELECT x+1 FROM tab WHERE x+1!=5
** UNION ALL
** SELECT y+1 FROM tab WHERE y+1!=5
** UNION ALL
** SELECT abs(z*2)+1 FROM tab2 WHERE abs(z*2)+1!=5
** ORDER BY 1
**
** We call this the "compound-subquery flattening".
*/
for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){
Select *pNew;
ExprList *pOrderBy = p->pOrderBy;
Expr *pLimit = p->pLimit;
Select *pPrior = p->pPrior;
p->pOrderBy = 0;
p->pSrc = 0;
p->pPrior = 0;
p->pLimit = 0;
pNew = sqlite3SelectDup(db, p, 0);
p->pLimit = pLimit;
p->pOrderBy = pOrderBy;
p->pSrc = pSrc;
p->op = TK_ALL;
if( pNew==0 ){
p->pPrior = pPrior;
}else{
pNew->pPrior = pPrior;
if( pPrior ) pPrior->pNext = pNew;
pNew->pNext = p;
p->pPrior = pNew;
SELECTTRACE(2,pParse,p,("compound-subquery flattener"
" creates %u as peer\n",pNew->selId));
}
if( db->mallocFailed ) return 1;
}
/* Begin flattening the iFrom-th entry of the FROM clause
** in the outer query.
*/
pSub = pSub1 = pSubitem->pSelect;
/* Delete the transient table structure associated with the
** subquery
*/
sqlite3DbFree(db, pSubitem->zDatabase);
sqlite3DbFree(db, pSubitem->zName);
sqlite3DbFree(db, pSubitem->zAlias);
pSubitem->zDatabase = 0;
pSubitem->zName = 0;
pSubitem->zAlias = 0;
pSubitem->pSelect = 0;
/* Defer deleting the Table object associated with the
** subquery until code generation is
** complete, since there may still exist Expr.pTab entries that
** refer to the subquery even after flattening. Ticket #3346.
**
** pSubitem->pTab is always non-NULL by test restrictions and tests above.
*/
if( ALWAYS(pSubitem->pTab!=0) ){
Table *pTabToDel = pSubitem->pTab;
if( pTabToDel->nTabRef==1 ){
Parse *pToplevel = sqlite3ParseToplevel(pParse);
pTabToDel->pNextZombie = pToplevel->pZombieTab;
pToplevel->pZombieTab = pTabToDel;
}else{
pTabToDel->nTabRef--;
}
pSubitem->pTab = 0;
}
/* The following loop runs once for each term in a compound-subquery
** flattening (as described above). If we are doing a different kind
** of flattening - a flattening other than a compound-subquery flattening -
** then this loop only runs once.
**
** This loop moves all of the FROM elements of the subquery into the
** the FROM clause of the outer query. Before doing this, remember
** the cursor number for the original outer query FROM element in
** iParent. The iParent cursor will never be used. Subsequent code
** will scan expressions looking for iParent references and replace
** those references with expressions that resolve to the subquery FROM
** elements we are now copying in.
*/
for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){
int nSubSrc;
u8 jointype = 0;
assert( pSub!=0 );
pSubSrc = pSub->pSrc; /* FROM clause of subquery */
nSubSrc = pSubSrc->nSrc; /* Number of terms in subquery FROM clause */
pSrc = pParent->pSrc; /* FROM clause of the outer query */
if( pSrc ){
assert( pParent==p ); /* First time through the loop */
jointype = pSubitem->fg.jointype;
}else{
assert( pParent!=p ); /* 2nd and subsequent times through the loop */
pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
if( pSrc==0 ) break;
pParent->pSrc = pSrc;
}
/* The subquery uses a single slot of the FROM clause of the outer
** query. If the subquery has more than one element in its FROM clause,
** then expand the outer query to make space for it to hold all elements
** of the subquery.
**
** Example:
**
** SELECT * FROM tabA, (SELECT * FROM sub1, sub2), tabB;
**
** The outer query has 3 slots in its FROM clause. One slot of the
** outer query (the middle slot) is used by the subquery. The next
** block of code will expand the outer query FROM clause to 4 slots.
** The middle slot is expanded to two slots in order to make space
** for the two elements in the FROM clause of the subquery.
*/
if( nSubSrc>1 ){
pSrc = sqlite3SrcListEnlarge(pParse, pSrc, nSubSrc-1,iFrom+1);
if( pSrc==0 ) break;
pParent->pSrc = pSrc;
}
/* Transfer the FROM clause terms from the subquery into the
** outer query.
*/
for(i=0; i<nSubSrc; i++){
sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing);
assert( pSrc->a[i+iFrom].fg.isTabFunc==0 );
pSrc->a[i+iFrom] = pSubSrc->a[i];
iNewParent = pSubSrc->a[i].iCursor;
memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
}
pSrc->a[iFrom].fg.jointype = jointype;
/* Now begin substituting subquery result set expressions for
** references to the iParent in the outer query.
**
** Example:
**
** SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
** \ \_____________ subquery __________/ /
** \_____________________ outer query ______________________________/
**
** We look at every expression in the outer query and every place we see
** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
*/
if( pSub->pOrderBy && (pParent->selFlags & SF_NoopOrderBy)==0 ){
/* At this point, any non-zero iOrderByCol values indicate that the
** ORDER BY column expression is identical to the iOrderByCol'th
** expression returned by SELECT statement pSub. Since these values
** do not necessarily correspond to columns in SELECT statement pParent,
** zero them before transfering the ORDER BY clause.
**
** Not doing this may cause an error if a subsequent call to this
** function attempts to flatten a compound sub-query into pParent
** (the only way this can happen is if the compound sub-query is
** currently part of pSub->pSrc). See ticket [d11a6e908f]. */
ExprList *pOrderBy = pSub->pOrderBy;
for(i=0; i<pOrderBy->nExpr; i++){
pOrderBy->a[i].u.x.iOrderByCol = 0;
}
assert( pParent->pOrderBy==0 );
pParent->pOrderBy = pOrderBy;
pSub->pOrderBy = 0;
}
pWhere = pSub->pWhere;
pSub->pWhere = 0;
if( isLeftJoin>0 ){
sqlite3SetJoinExpr(pWhere, iNewParent);
}
if( pWhere ){
if( pParent->pWhere ){
pParent->pWhere = sqlite3PExpr(pParse, TK_AND, pWhere, pParent->pWhere);
}else{
pParent->pWhere = pWhere;
}
}
if( db->mallocFailed==0 ){
SubstContext x;
x.pParse = pParse;
x.iTable = iParent;
x.iNewTable = iNewParent;
x.isLeftJoin = isLeftJoin;
x.pEList = pSub->pEList;
substSelect(&x, pParent, 0);
}
/* The flattened query is a compound if either the inner or the
** outer query is a compound. */
pParent->selFlags |= pSub->selFlags & SF_Compound;
assert( (pSub->selFlags & SF_Distinct)==0 ); /* restriction (17b) */
/*
** SELECT ... FROM (SELECT ... LIMIT a OFFSET b) LIMIT x OFFSET y;
**
** One is tempted to try to add a and b to combine the limits. But this
** does not work if either limit is negative.
*/
if( pSub->pLimit ){
pParent->pLimit = pSub->pLimit;
pSub->pLimit = 0;
}
/* Recompute the SrcList_item.colUsed masks for the flattened
** tables. */
for(i=0; i<nSubSrc; i++){
recomputeColumnsUsed(pParent, &pSrc->a[i+iFrom]);
}
}
/* Finially, delete what is left of the subquery and return
** success.
*/
sqlite3AggInfoPersistWalkerInit(&w, pParse);
sqlite3WalkSelect(&w,pSub1);
sqlite3SelectDelete(db, pSub1);
#if SELECTTRACE_ENABLED
if( sqlite3_unsupported_selecttrace & 0x100 ){
SELECTTRACE(0x100,pParse,p,("After flattening:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
return 1;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
/*
** A structure to keep track of all of the column values that are fixed to
** a known value due to WHERE clause constraints of the form COLUMN=VALUE.
*/
typedef struct WhereConst WhereConst;
struct WhereConst {
Parse *pParse; /* Parsing context */
int nConst; /* Number for COLUMN=CONSTANT terms */
int nChng; /* Number of times a constant is propagated */
Expr **apExpr; /* [i*2] is COLUMN and [i*2+1] is VALUE */
};
/*
** Add a new entry to the pConst object. Except, do not add duplicate
** pColumn entires. Also, do not add if doing so would not be appropriate.
**
** The caller guarantees the pColumn is a column and pValue is a constant.
** This routine has to do some additional checks before completing the
** insert.
*/
static void constInsert(
WhereConst *pConst, /* The WhereConst into which we are inserting */
Expr *pColumn, /* The COLUMN part of the constraint */
Expr *pValue, /* The VALUE part of the constraint */
Expr *pExpr /* Overall expression: COLUMN=VALUE or VALUE=COLUMN */
){
int i;
assert( pColumn->op==TK_COLUMN );
assert( sqlite3ExprIsConstant(pValue) );
if( ExprHasProperty(pColumn, EP_FixedCol) ) return;
if( sqlite3ExprAffinity(pValue)!=0 ) return;
if( !sqlite3IsBinary(sqlite3ExprCompareCollSeq(pConst->pParse,pExpr)) ){
return;
}
/* 2018-10-25 ticket [cf5ed20f]
** Make sure the same pColumn is not inserted more than once */
for(i=0; i<pConst->nConst; i++){
const Expr *pE2 = pConst->apExpr[i*2];
assert( pE2->op==TK_COLUMN );
if( pE2->iTable==pColumn->iTable
&& pE2->iColumn==pColumn->iColumn
){
return; /* Already present. Return without doing anything. */
}
}
pConst->nConst++;
pConst->apExpr = sqlite3DbReallocOrFree(pConst->pParse->db, pConst->apExpr,
pConst->nConst*2*sizeof(Expr*));
if( pConst->apExpr==0 ){
pConst->nConst = 0;
}else{
pConst->apExpr[pConst->nConst*2-2] = pColumn;
pConst->apExpr[pConst->nConst*2-1] = pValue;
}
}
/*
** Find all terms of COLUMN=VALUE or VALUE=COLUMN in pExpr where VALUE
** is a constant expression and where the term must be true because it
** is part of the AND-connected terms of the expression. For each term
** found, add it to the pConst structure.
*/
static void findConstInWhere(WhereConst *pConst, Expr *pExpr){
Expr *pRight, *pLeft;
if( pExpr==0 ) return;
if( ExprHasProperty(pExpr, EP_FromJoin) ) return;
if( pExpr->op==TK_AND ){
findConstInWhere(pConst, pExpr->pRight);
findConstInWhere(pConst, pExpr->pLeft);
return;
}
if( pExpr->op!=TK_EQ ) return;
pRight = pExpr->pRight;
pLeft = pExpr->pLeft;
assert( pRight!=0 );
assert( pLeft!=0 );
if( pRight->op==TK_COLUMN && sqlite3ExprIsConstant(pLeft) ){
constInsert(pConst,pRight,pLeft,pExpr);
}
if( pLeft->op==TK_COLUMN && sqlite3ExprIsConstant(pRight) ){
constInsert(pConst,pLeft,pRight,pExpr);
}
}
/*
** This is a Walker expression callback. pExpr is a candidate expression
** to be replaced by a value. If pExpr is equivalent to one of the
** columns named in pWalker->u.pConst, then overwrite it with its
** corresponding value.
*/
static int propagateConstantExprRewrite(Walker *pWalker, Expr *pExpr){
int i;
WhereConst *pConst;
if( pExpr->op!=TK_COLUMN ) return WRC_Continue;
if( ExprHasProperty(pExpr, EP_FixedCol|EP_FromJoin) ){
testcase( ExprHasProperty(pExpr, EP_FixedCol) );
testcase( ExprHasProperty(pExpr, EP_FromJoin) );
return WRC_Continue;
}
pConst = pWalker->u.pConst;
for(i=0; i<pConst->nConst; i++){
Expr *pColumn = pConst->apExpr[i*2];
if( pColumn==pExpr ) continue;
if( pColumn->iTable!=pExpr->iTable ) continue;
if( pColumn->iColumn!=pExpr->iColumn ) continue;
/* A match is found. Add the EP_FixedCol property */
pConst->nChng++;
ExprClearProperty(pExpr, EP_Leaf);
ExprSetProperty(pExpr, EP_FixedCol);
assert( pExpr->pLeft==0 );
pExpr->pLeft = sqlite3ExprDup(pConst->pParse->db, pConst->apExpr[i*2+1], 0);
break;
}
return WRC_Prune;
}
/*
** The WHERE-clause constant propagation optimization.
**
** If the WHERE clause contains terms of the form COLUMN=CONSTANT or
** CONSTANT=COLUMN that are top-level AND-connected terms that are not
** part of a ON clause from a LEFT JOIN, then throughout the query
** replace all other occurrences of COLUMN with CONSTANT.
**
** For example, the query:
**
** SELECT * FROM t1, t2, t3 WHERE t1.a=39 AND t2.b=t1.a AND t3.c=t2.b
**
** Is transformed into
**
** SELECT * FROM t1, t2, t3 WHERE t1.a=39 AND t2.b=39 AND t3.c=39
**
** Return true if any transformations where made and false if not.
**
** Implementation note: Constant propagation is tricky due to affinity
** and collating sequence interactions. Consider this example:
**
** CREATE TABLE t1(a INT,b TEXT);
** INSERT INTO t1 VALUES(123,'0123');
** SELECT * FROM t1 WHERE a=123 AND b=a;
** SELECT * FROM t1 WHERE a=123 AND b=123;
**
** The two SELECT statements above should return different answers. b=a
** is alway true because the comparison uses numeric affinity, but b=123
** is false because it uses text affinity and '0123' is not the same as '123'.
** To work around this, the expression tree is not actually changed from
** "b=a" to "b=123" but rather the "a" in "b=a" is tagged with EP_FixedCol
** and the "123" value is hung off of the pLeft pointer. Code generator
** routines know to generate the constant "123" instead of looking up the
** column value. Also, to avoid collation problems, this optimization is
** only attempted if the "a=123" term uses the default BINARY collation.
*/
static int propagateConstants(
Parse *pParse, /* The parsing context */
Select *p /* The query in which to propagate constants */
){
WhereConst x;
Walker w;
int nChng = 0;
x.pParse = pParse;
do{
x.nConst = 0;
x.nChng = 0;
x.apExpr = 0;
findConstInWhere(&x, p->pWhere);
if( x.nConst ){
memset(&w, 0, sizeof(w));
w.pParse = pParse;
w.xExprCallback = propagateConstantExprRewrite;
w.xSelectCallback = sqlite3SelectWalkNoop;
w.xSelectCallback2 = 0;
w.walkerDepth = 0;
w.u.pConst = &x;
sqlite3WalkExpr(&w, p->pWhere);
sqlite3DbFree(x.pParse->db, x.apExpr);
nChng += x.nChng;
}
}while( x.nChng );
return nChng;
}
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
/*
** Make copies of relevant WHERE clause terms of the outer query into
** the WHERE clause of subquery. Example:
**
** SELECT * FROM (SELECT a AS x, c-d AS y FROM t1) WHERE x=5 AND y=10;
**
** Transformed into:
**
** SELECT * FROM (SELECT a AS x, c-d AS y FROM t1 WHERE a=5 AND c-d=10)
** WHERE x=5 AND y=10;
**
** The hope is that the terms added to the inner query will make it more
** efficient.
**
** Do not attempt this optimization if:
**
** (1) (** This restriction was removed on 2017-09-29. We used to
** disallow this optimization for aggregate subqueries, but now
** it is allowed by putting the extra terms on the HAVING clause.
** The added HAVING clause is pointless if the subquery lacks
** a GROUP BY clause. But such a HAVING clause is also harmless
** so there does not appear to be any reason to add extra logic
** to suppress it. **)
**
** (2) The inner query is the recursive part of a common table expression.
**
** (3) The inner query has a LIMIT clause (since the changes to the WHERE
** clause would change the meaning of the LIMIT).
**
** (4) The inner query is the right operand of a LEFT JOIN and the
** expression to be pushed down does not come from the ON clause
** on that LEFT JOIN.
**
** (5) The WHERE clause expression originates in the ON or USING clause
** of a LEFT JOIN where iCursor is not the right-hand table of that
** left join. An example:
**
** SELECT *
** FROM (SELECT 1 AS a1 UNION ALL SELECT 2) AS aa
** JOIN (SELECT 1 AS b2 UNION ALL SELECT 2) AS bb ON (a1=b2)
** LEFT JOIN (SELECT 8 AS c3 UNION ALL SELECT 9) AS cc ON (b2=2);
**
** The correct answer is three rows: (1,1,NULL),(2,2,8),(2,2,9).
** But if the (b2=2) term were to be pushed down into the bb subquery,
** then the (1,1,NULL) row would be suppressed.
**
** (6) The inner query features one or more window-functions (since
** changes to the WHERE clause of the inner query could change the
** window over which window functions are calculated).
**
** Return 0 if no changes are made and non-zero if one or more WHERE clause
** terms are duplicated into the subquery.
*/
static int pushDownWhereTerms(
Parse *pParse, /* Parse context (for malloc() and error reporting) */
Select *pSubq, /* The subquery whose WHERE clause is to be augmented */
Expr *pWhere, /* The WHERE clause of the outer query */
int iCursor, /* Cursor number of the subquery */
int isLeftJoin /* True if pSubq is the right term of a LEFT JOIN */
){
Expr *pNew;
int nChng = 0;
Select *pSel;
if( pWhere==0 ) return 0;
if( pSubq->selFlags & SF_Recursive ) return 0; /* restriction (2) */
#ifndef SQLITE_OMIT_WINDOWFUNC
for(pSel=pSubq; pSel; pSel=pSel->pPrior){
if( pSel->pWin ) return 0; /* restriction (6) */
}
#endif
#ifdef SQLITE_DEBUG
/* Only the first term of a compound can have a WITH clause. But make
** sure no other terms are marked SF_Recursive in case something changes
** in the future.
*/
{
Select *pX;
for(pX=pSubq; pX; pX=pX->pPrior){
assert( (pX->selFlags & (SF_Recursive))==0 );
}
}
#endif
if( pSubq->pLimit!=0 ){
return 0; /* restriction (3) */
}
while( pWhere->op==TK_AND ){
nChng += pushDownWhereTerms(pParse, pSubq, pWhere->pRight,
iCursor, isLeftJoin);
pWhere = pWhere->pLeft;
}
if( isLeftJoin
&& (ExprHasProperty(pWhere,EP_FromJoin)==0
|| pWhere->iRightJoinTable!=iCursor)
){
return 0; /* restriction (4) */
}
if( ExprHasProperty(pWhere,EP_FromJoin) && pWhere->iRightJoinTable!=iCursor ){
return 0; /* restriction (5) */
}
if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){
nChng++;
while( pSubq ){
SubstContext x;
pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
unsetJoinExpr(pNew, -1);
x.pParse = pParse;
x.iTable = iCursor;
x.iNewTable = iCursor;
x.isLeftJoin = 0;
x.pEList = pSubq->pEList;
pNew = substExpr(&x, pNew);
if( pSubq->selFlags & SF_Aggregate ){
pSubq->pHaving = sqlite3ExprAnd(pParse, pSubq->pHaving, pNew);
}else{
pSubq->pWhere = sqlite3ExprAnd(pParse, pSubq->pWhere, pNew);
}
pSubq = pSubq->pPrior;
}
}
return nChng;
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
/*
** The pFunc is the only aggregate function in the query. Check to see
** if the query is a candidate for the min/max optimization.
**
** If the query is a candidate for the min/max optimization, then set
** *ppMinMax to be an ORDER BY clause to be used for the optimization
** and return either WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX depending on
** whether pFunc is a min() or max() function.
**
** If the query is not a candidate for the min/max optimization, return
** WHERE_ORDERBY_NORMAL (which must be zero).
**
** This routine must be called after aggregate functions have been
** located but before their arguments have been subjected to aggregate
** analysis.
*/
static u8 minMaxQuery(sqlite3 *db, Expr *pFunc, ExprList **ppMinMax){
int eRet = WHERE_ORDERBY_NORMAL; /* Return value */
ExprList *pEList = pFunc->x.pList; /* Arguments to agg function */
const char *zFunc; /* Name of aggregate function pFunc */
ExprList *pOrderBy;
u8 sortFlags = 0;
assert( *ppMinMax==0 );
assert( pFunc->op==TK_AGG_FUNCTION );
assert( !IsWindowFunc(pFunc) );
if( pEList==0 || pEList->nExpr!=1 || ExprHasProperty(pFunc, EP_WinFunc) ){
return eRet;
}
zFunc = pFunc->u.zToken;
if( sqlite3StrICmp(zFunc, "min")==0 ){
eRet = WHERE_ORDERBY_MIN;
if( sqlite3ExprCanBeNull(pEList->a[0].pExpr) ){
sortFlags = KEYINFO_ORDER_BIGNULL;
}
}else if( sqlite3StrICmp(zFunc, "max")==0 ){
eRet = WHERE_ORDERBY_MAX;
sortFlags = KEYINFO_ORDER_DESC;
}else{
return eRet;
}
*ppMinMax = pOrderBy = sqlite3ExprListDup(db, pEList, 0);
assert( pOrderBy!=0 || db->mallocFailed );
if( pOrderBy ) pOrderBy->a[0].sortFlags = sortFlags;
return eRet;
}
/*
** The select statement passed as the first argument is an aggregate query.
** The second argument is the associated aggregate-info object. This
** function tests if the SELECT is of the form:
**
** SELECT count(*) FROM <tbl>
**
** where table is a database table, not a sub-select or view. If the query
** does match this pattern, then a pointer to the Table object representing
** <tbl> is returned. Otherwise, 0 is returned.
*/
static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){
Table *pTab;
Expr *pExpr;
assert( !p->pGroupBy );
if( p->pWhere || p->pEList->nExpr!=1
|| p->pSrc->nSrc!=1 || p->pSrc->a[0].pSelect
){
return 0;
}
pTab = p->pSrc->a[0].pTab;
pExpr = p->pEList->a[0].pExpr;
assert( pTab && !pTab->pSelect && pExpr );
if( IsVirtual(pTab) ) return 0;
if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
if( NEVER(pAggInfo->nFunc==0) ) return 0;
if( (pAggInfo->aFunc[0].pFunc->funcFlags&SQLITE_FUNC_COUNT)==0 ) return 0;
if( ExprHasProperty(pExpr, EP_Distinct|EP_WinFunc) ) return 0;
return pTab;
}
/*
** If the source-list item passed as an argument was augmented with an
** INDEXED BY clause, then try to locate the specified index. If there
** was such a clause and the named index cannot be found, return
** SQLITE_ERROR and leave an error in pParse. Otherwise, populate
** pFrom->pIndex and return SQLITE_OK.
*/
SQLITE_PRIVATE int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){
if( pFrom->pTab && pFrom->fg.isIndexedBy ){
Table *pTab = pFrom->pTab;
char *zIndexedBy = pFrom->u1.zIndexedBy;
Index *pIdx;
for(pIdx=pTab->pIndex;
pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy);
pIdx=pIdx->pNext
);
if( !pIdx ){
sqlite3ErrorMsg(pParse, "no such index: %s", zIndexedBy, 0);
pParse->checkSchema = 1;
return SQLITE_ERROR;
}
pFrom->pIBIndex = pIdx;
}
return SQLITE_OK;
}
/*
** Detect compound SELECT statements that use an ORDER BY clause with
** an alternative collating sequence.
**
** SELECT ... FROM t1 EXCEPT SELECT ... FROM t2 ORDER BY .. COLLATE ...
**
** These are rewritten as a subquery:
**
** SELECT * FROM (SELECT ... FROM t1 EXCEPT SELECT ... FROM t2)
** ORDER BY ... COLLATE ...
**
** This transformation is necessary because the multiSelectOrderBy() routine
** above that generates the code for a compound SELECT with an ORDER BY clause
** uses a merge algorithm that requires the same collating sequence on the
** result columns as on the ORDER BY clause. See ticket
** http://www.sqlite.org/src/info/6709574d2a
**
** This transformation is only needed for EXCEPT, INTERSECT, and UNION.
** The UNION ALL operator works fine with multiSelectOrderBy() even when
** there are COLLATE terms in the ORDER BY.
*/
static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){
int i;
Select *pNew;
Select *pX;
sqlite3 *db;
struct ExprList_item *a;
SrcList *pNewSrc;
Parse *pParse;
Token dummy;
if( p->pPrior==0 ) return WRC_Continue;
if( p->pOrderBy==0 ) return WRC_Continue;
for(pX=p; pX && (pX->op==TK_ALL || pX->op==TK_SELECT); pX=pX->pPrior){}
if( pX==0 ) return WRC_Continue;
a = p->pOrderBy->a;
#ifndef SQLITE_OMIT_WINDOWFUNC
/* If iOrderByCol is already non-zero, then it has already been matched
** to a result column of the SELECT statement. This occurs when the
** SELECT is rewritten for window-functions processing and then passed
** to sqlite3SelectPrep() and similar a second time. The rewriting done
** by this function is not required in this case. */
if( a[0].u.x.iOrderByCol ) return WRC_Continue;
#endif
for(i=p->pOrderBy->nExpr-1; i>=0; i--){
if( a[i].pExpr->flags & EP_Collate ) break;
}
if( i<0 ) return WRC_Continue;
/* If we reach this point, that means the transformation is required. */
pParse = pWalker->pParse;
db = pParse->db;
pNew = sqlite3DbMallocZero(db, sizeof(*pNew) );
if( pNew==0 ) return WRC_Abort;
memset(&dummy, 0, sizeof(dummy));
pNewSrc = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&dummy,pNew,0,0);
if( pNewSrc==0 ) return WRC_Abort;
*pNew = *p;
p->pSrc = pNewSrc;
p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ASTERISK, 0));
p->op = TK_SELECT;
p->pWhere = 0;
pNew->pGroupBy = 0;
pNew->pHaving = 0;
pNew->pOrderBy = 0;
p->pPrior = 0;
p->pNext = 0;
p->pWith = 0;
#ifndef SQLITE_OMIT_WINDOWFUNC
p->pWinDefn = 0;
#endif
p->selFlags &= ~SF_Compound;
assert( (p->selFlags & SF_Converted)==0 );
p->selFlags |= SF_Converted;
assert( pNew->pPrior!=0 );
pNew->pPrior->pNext = pNew;
pNew->pLimit = 0;
return WRC_Continue;
}
/*
** Check to see if the FROM clause term pFrom has table-valued function
** arguments. If it does, leave an error message in pParse and return
** non-zero, since pFrom is not allowed to be a table-valued function.
*/
static int cannotBeFunction(Parse *pParse, struct SrcList_item *pFrom){
if( pFrom->fg.isTabFunc ){
sqlite3ErrorMsg(pParse, "'%s' is not a function", pFrom->zName);
return 1;
}
return 0;
}
#ifndef SQLITE_OMIT_CTE
/*
** Argument pWith (which may be NULL) points to a linked list of nested
** WITH contexts, from inner to outermost. If the table identified by
** FROM clause element pItem is really a common-table-expression (CTE)
** then return a pointer to the CTE definition for that table. Otherwise
** return NULL.
**
** If a non-NULL value is returned, set *ppContext to point to the With
** object that the returned CTE belongs to.
*/
static struct Cte *searchWith(
With *pWith, /* Current innermost WITH clause */
struct SrcList_item *pItem, /* FROM clause element to resolve */
With **ppContext /* OUT: WITH clause return value belongs to */
){
const char *zName;
if( pItem->zDatabase==0 && (zName = pItem->zName)!=0 ){
With *p;
for(p=pWith; p; p=p->pOuter){
int i;
for(i=0; i<p->nCte; i++){
if( sqlite3StrICmp(zName, p->a[i].zName)==0 ){
*ppContext = p;
return &p->a[i];
}
}
}
}
return 0;
}
/* The code generator maintains a stack of active WITH clauses
** with the inner-most WITH clause being at the top of the stack.
**
** This routine pushes the WITH clause passed as the second argument
** onto the top of the stack. If argument bFree is true, then this
** WITH clause will never be popped from the stack. In this case it
** should be freed along with the Parse object. In other cases, when
** bFree==0, the With object will be freed along with the SELECT
** statement with which it is associated.
*/
SQLITE_PRIVATE void sqlite3WithPush(Parse *pParse, With *pWith, u8 bFree){
assert( bFree==0 || (pParse->pWith==0 && pParse->pWithToFree==0) );
if( pWith ){
assert( pParse->pWith!=pWith );
pWith->pOuter = pParse->pWith;
pParse->pWith = pWith;
if( bFree ) pParse->pWithToFree = pWith;
}
}
/*
** This function checks if argument pFrom refers to a CTE declared by
** a WITH clause on the stack currently maintained by the parser. And,
** if currently processing a CTE expression, if it is a recursive
** reference to the current CTE.
**
** If pFrom falls into either of the two categories above, pFrom->pTab
** and other fields are populated accordingly. The caller should check
** (pFrom->pTab!=0) to determine whether or not a successful match
** was found.
**
** Whether or not a match is found, SQLITE_OK is returned if no error
** occurs. If an error does occur, an error message is stored in the
** parser and some error code other than SQLITE_OK returned.
*/
static int withExpand(
Walker *pWalker,
struct SrcList_item *pFrom
){
Parse *pParse = pWalker->pParse;
sqlite3 *db = pParse->db;
struct Cte *pCte; /* Matched CTE (or NULL if no match) */
With *pWith; /* WITH clause that pCte belongs to */
assert( pFrom->pTab==0 );
if( pParse->nErr ){
return SQLITE_ERROR;
}
pCte = searchWith(pParse->pWith, pFrom, &pWith);
if( pCte ){
Table *pTab;
ExprList *pEList;
Select *pSel;
Select *pLeft; /* Left-most SELECT statement */
Select *pRecTerm; /* Left-most recursive term */
int bMayRecursive; /* True if compound joined by UNION [ALL] */
With *pSavedWith; /* Initial value of pParse->pWith */
int iRecTab = -1; /* Cursor for recursive table */
/* If pCte->zCteErr is non-NULL at this point, then this is an illegal
** recursive reference to CTE pCte. Leave an error in pParse and return
** early. If pCte->zCteErr is NULL, then this is not a recursive reference.
** In this case, proceed. */
if( pCte->zCteErr ){
sqlite3ErrorMsg(pParse, pCte->zCteErr, pCte->zName);
return SQLITE_ERROR;
}
if( cannotBeFunction(pParse, pFrom) ) return SQLITE_ERROR;
assert( pFrom->pTab==0 );
pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table));
if( pTab==0 ) return WRC_Abort;
pTab->nTabRef = 1;
pTab->zName = sqlite3DbStrDup(db, pCte->zName);
pTab->iPKey = -1;
pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid;
pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0);
if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;
assert( pFrom->pSelect );
/* Check if this is a recursive CTE. */
pRecTerm = pSel = pFrom->pSelect;
bMayRecursive = ( pSel->op==TK_ALL || pSel->op==TK_UNION );
while( bMayRecursive && pRecTerm->op==pSel->op ){
int i;
SrcList *pSrc = pRecTerm->pSrc;
assert( pRecTerm->pPrior!=0 );
for(i=0; i<pSrc->nSrc; i++){
struct SrcList_item *pItem = &pSrc->a[i];
if( pItem->zDatabase==0
&& pItem->zName!=0
&& 0==sqlite3StrICmp(pItem->zName, pCte->zName)
){
pItem->pTab = pTab;
pTab->nTabRef++;
pItem->fg.isRecursive = 1;
if( pRecTerm->selFlags & SF_Recursive ){
sqlite3ErrorMsg(pParse,
"multiple references to recursive table: %s", pCte->zName
);
return SQLITE_ERROR;
}
pRecTerm->selFlags |= SF_Recursive;
if( iRecTab<0 ) iRecTab = pParse->nTab++;
pItem->iCursor = iRecTab;
}
}
if( (pRecTerm->selFlags & SF_Recursive)==0 ) break;
pRecTerm = pRecTerm->pPrior;
}
pCte->zCteErr = "circular reference: %s";
pSavedWith = pParse->pWith;
pParse->pWith = pWith;
if( pSel->selFlags & SF_Recursive ){
assert( pRecTerm!=0 );
assert( (pRecTerm->selFlags & SF_Recursive)==0 );
assert( pRecTerm->pNext!=0 );
assert( (pRecTerm->pNext->selFlags & SF_Recursive)!=0 );
assert( pRecTerm->pWith==0 );
pRecTerm->pWith = pSel->pWith;
sqlite3WalkSelect(pWalker, pRecTerm);
pRecTerm->pWith = 0;
}else{
sqlite3WalkSelect(pWalker, pSel);
}
pParse->pWith = pWith;
for(pLeft=pSel; pLeft->pPrior; pLeft=pLeft->pPrior);
pEList = pLeft->pEList;
if( pCte->pCols ){
if( pEList && pEList->nExpr!=pCte->pCols->nExpr ){
sqlite3ErrorMsg(pParse, "table %s has %d values for %d columns",
pCte->zName, pEList->nExpr, pCte->pCols->nExpr
);
pParse->pWith = pSavedWith;
return SQLITE_ERROR;
}
pEList = pCte->pCols;
}
sqlite3ColumnsFromExprList(pParse, pEList, &pTab->nCol, &pTab->aCol);
if( bMayRecursive ){
if( pSel->selFlags & SF_Recursive ){
pCte->zCteErr = "multiple recursive references: %s";
}else{
pCte->zCteErr = "recursive reference in a subquery: %s";
}
sqlite3WalkSelect(pWalker, pSel);
}
pCte->zCteErr = 0;
pParse->pWith = pSavedWith;
}
return SQLITE_OK;
}
#endif
#ifndef SQLITE_OMIT_CTE
/*
** If the SELECT passed as the second argument has an associated WITH
** clause, pop it from the stack stored as part of the Parse object.
**
** This function is used as the xSelectCallback2() callback by
** sqlite3SelectExpand() when walking a SELECT tree to resolve table
** names and other FROM clause elements.
*/
static void selectPopWith(Walker *pWalker, Select *p){
Parse *pParse = pWalker->pParse;
if( OK_IF_ALWAYS_TRUE(pParse->pWith) && p->pPrior==0 ){
With *pWith = findRightmost(p)->pWith;
if( pWith!=0 ){
assert( pParse->pWith==pWith || pParse->nErr );
pParse->pWith = pWith->pOuter;
}
}
}
#else
#define selectPopWith 0
#endif
/*
** The SrcList_item structure passed as the second argument represents a
** sub-query in the FROM clause of a SELECT statement. This function
** allocates and populates the SrcList_item.pTab object. If successful,
** SQLITE_OK is returned. Otherwise, if an OOM error is encountered,
** SQLITE_NOMEM.
*/
SQLITE_PRIVATE int sqlite3ExpandSubquery(Parse *pParse, struct SrcList_item *pFrom){
Select *pSel = pFrom->pSelect;
Table *pTab;
assert( pSel );
pFrom->pTab = pTab = sqlite3DbMallocZero(pParse->db, sizeof(Table));
if( pTab==0 ) return SQLITE_NOMEM;
pTab->nTabRef = 1;
if( pFrom->zAlias ){
pTab->zName = sqlite3DbStrDup(pParse->db, pFrom->zAlias);
}else{
pTab->zName = sqlite3MPrintf(pParse->db, "subquery_%u", pSel->selId);
}
while( pSel->pPrior ){ pSel = pSel->pPrior; }
sqlite3ColumnsFromExprList(pParse, pSel->pEList,&pTab->nCol,&pTab->aCol);
pTab->iPKey = -1;
pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) );
pTab->tabFlags |= TF_Ephemeral;
return pParse->nErr ? SQLITE_ERROR : SQLITE_OK;
}
/*
** This routine is a Walker callback for "expanding" a SELECT statement.
** "Expanding" means to do the following:
**
** (1) Make sure VDBE cursor numbers have been assigned to every
** element of the FROM clause.
**
** (2) Fill in the pTabList->a[].pTab fields in the SrcList that
** defines FROM clause. When views appear in the FROM clause,
** fill pTabList->a[].pSelect with a copy of the SELECT statement
** that implements the view. A copy is made of the view's SELECT
** statement so that we can freely modify or delete that statement
** without worrying about messing up the persistent representation
** of the view.
**
** (3) Add terms to the WHERE clause to accommodate the NATURAL keyword
** on joins and the ON and USING clause of joins.
**
** (4) Scan the list of columns in the result set (pEList) looking
** for instances of the "*" operator or the TABLE.* operator.
** If found, expand each "*" to be every column in every table
** and TABLE.* to be every column in TABLE.
**
*/
static int selectExpander(Walker *pWalker, Select *p){
Parse *pParse = pWalker->pParse;
int i, j, k;
SrcList *pTabList;
ExprList *pEList;
struct SrcList_item *pFrom;
sqlite3 *db = pParse->db;
Expr *pE, *pRight, *pExpr;
u16 selFlags = p->selFlags;
u32 elistFlags = 0;
p->selFlags |= SF_Expanded;
if( db->mallocFailed ){
return WRC_Abort;
}
assert( p->pSrc!=0 );
if( (selFlags & SF_Expanded)!=0 ){
return WRC_Prune;
}
if( pWalker->eCode ){
/* Renumber selId because it has been copied from a view */
p->selId = ++pParse->nSelect;
}
pTabList = p->pSrc;
pEList = p->pEList;
sqlite3WithPush(pParse, p->pWith, 0);
/* Make sure cursor numbers have been assigned to all entries in
** the FROM clause of the SELECT statement.
*/
sqlite3SrcListAssignCursors(pParse, pTabList);
/* Look up every table named in the FROM clause of the select. If
** an entry of the FROM clause is a subquery instead of a table or view,
** then create a transient table structure to describe the subquery.
*/
for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
Table *pTab;
assert( pFrom->fg.isRecursive==0 || pFrom->pTab!=0 );
if( pFrom->pTab ) continue;
assert( pFrom->fg.isRecursive==0 );
#ifndef SQLITE_OMIT_CTE
if( withExpand(pWalker, pFrom) ) return WRC_Abort;
if( pFrom->pTab ) {} else
#endif
if( pFrom->zName==0 ){
#ifndef SQLITE_OMIT_SUBQUERY
Select *pSel = pFrom->pSelect;
/* A sub-query in the FROM clause of a SELECT */
assert( pSel!=0 );
assert( pFrom->pTab==0 );
if( sqlite3WalkSelect(pWalker, pSel) ) return WRC_Abort;
if( sqlite3ExpandSubquery(pParse, pFrom) ) return WRC_Abort;
#endif
}else{
/* An ordinary table or view name in the FROM clause */
assert( pFrom->pTab==0 );
pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom);
if( pTab==0 ) return WRC_Abort;
if( pTab->nTabRef>=0xffff ){
sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535",
pTab->zName);
pFrom->pTab = 0;
return WRC_Abort;
}
pTab->nTabRef++;
if( !IsVirtual(pTab) && cannotBeFunction(pParse, pFrom) ){
return WRC_Abort;
}
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
if( IsVirtual(pTab) || pTab->pSelect ){
i16 nCol;
u8 eCodeOrig = pWalker->eCode;
if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort;
assert( pFrom->pSelect==0 );
if( pTab->pSelect && (db->flags & SQLITE_EnableView)==0 ){
sqlite3ErrorMsg(pParse, "access to view \"%s\" prohibited",
pTab->zName);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pTab)
&& pFrom->fg.fromDDL
&& ALWAYS(pTab->pVTable!=0)
&& pTab->pVTable->eVtabRisk > ((db->flags & SQLITE_TrustedSchema)!=0)
){
sqlite3ErrorMsg(pParse, "unsafe use of virtual table \"%s\"",
pTab->zName);
}
#endif
pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect, 0);
nCol = pTab->nCol;
pTab->nCol = -1;
pWalker->eCode = 1; /* Turn on Select.selId renumbering */
sqlite3WalkSelect(pWalker, pFrom->pSelect);
pWalker->eCode = eCodeOrig;
pTab->nCol = nCol;
}
#endif
}
/* Locate the index named by the INDEXED BY clause, if any. */
if( sqlite3IndexedByLookup(pParse, pFrom) ){
return WRC_Abort;
}
}
/* Process NATURAL keywords, and ON and USING clauses of joins.
*/
if( pParse->nErr || db->mallocFailed || sqliteProcessJoin(pParse, p) ){
return WRC_Abort;
}
/* For every "*" that occurs in the column list, insert the names of
** all columns in all tables. And for every TABLE.* insert the names
** of all columns in TABLE. The parser inserted a special expression
** with the TK_ASTERISK operator for each "*" that it found in the column
** list. The following code just has to locate the TK_ASTERISK
** expressions and expand each one to the list of all columns in
** all tables.
**
** The first loop just checks to see if there are any "*" operators
** that need expanding.
*/
for(k=0; k<pEList->nExpr; k++){
pE = pEList->a[k].pExpr;
if( pE->op==TK_ASTERISK ) break;
assert( pE->op!=TK_DOT || pE->pRight!=0 );
assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) );
if( pE->op==TK_DOT && pE->pRight->op==TK_ASTERISK ) break;
elistFlags |= pE->flags;
}
if( k<pEList->nExpr ){
/*
** If we get here it means the result set contains one or more "*"
** operators that need to be expanded. Loop through each expression
** in the result set and expand them one by one.
*/
struct ExprList_item *a = pEList->a;
ExprList *pNew = 0;
int flags = pParse->db->flags;
int longNames = (flags & SQLITE_FullColNames)!=0
&& (flags & SQLITE_ShortColNames)==0;
for(k=0; k<pEList->nExpr; k++){
pE = a[k].pExpr;
elistFlags |= pE->flags;
pRight = pE->pRight;
assert( pE->op!=TK_DOT || pRight!=0 );
if( pE->op!=TK_ASTERISK
&& (pE->op!=TK_DOT || pRight->op!=TK_ASTERISK)
){
/* This particular expression does not need to be expanded.
*/
pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr);
if( pNew ){
pNew->a[pNew->nExpr-1].zEName = a[k].zEName;
pNew->a[pNew->nExpr-1].eEName = a[k].eEName;
a[k].zEName = 0;
}
a[k].pExpr = 0;
}else{
/* This expression is a "*" or a "TABLE.*" and needs to be
** expanded. */
int tableSeen = 0; /* Set to 1 when TABLE matches */
char *zTName = 0; /* text of name of TABLE */
if( pE->op==TK_DOT ){
assert( pE->pLeft!=0 );
assert( !ExprHasProperty(pE->pLeft, EP_IntValue) );
zTName = pE->pLeft->u.zToken;
}
for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
Table *pTab = pFrom->pTab;
Select *pSub = pFrom->pSelect;
char *zTabName = pFrom->zAlias;
const char *zSchemaName = 0;
int iDb;
if( zTabName==0 ){
zTabName = pTab->zName;
}
if( db->mallocFailed ) break;
if( pSub==0 || (pSub->selFlags & SF_NestedFrom)==0 ){
pSub = 0;
if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){
continue;
}
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
zSchemaName = iDb>=0 ? db->aDb[iDb].zDbSName : "*";
}
for(j=0; j<pTab->nCol; j++){
char *zName = pTab->aCol[j].zName;
char *zColname; /* The computed column name */
char *zToFree; /* Malloced string that needs to be freed */
Token sColname; /* Computed column name as a token */
assert( zName );
if( zTName && pSub
&& sqlite3MatchEName(&pSub->pEList->a[j], 0, zTName, 0)==0
){
continue;
}
/* If a column is marked as 'hidden', omit it from the expanded
** result-set list unless the SELECT has the SF_IncludeHidden
** bit set.
*/
if( (p->selFlags & SF_IncludeHidden)==0
&& IsHiddenColumn(&pTab->aCol[j])
){
continue;
}
tableSeen = 1;
if( i>0 && zTName==0 ){
if( (pFrom->fg.jointype & JT_NATURAL)!=0
&& tableAndColumnIndex(pTabList, i, zName, 0, 0, 1)
){
/* In a NATURAL join, omit the join columns from the
** table to the right of the join */
continue;
}
if( sqlite3IdListIndex(pFrom->pUsing, zName)>=0 ){
/* In a join with a USING clause, omit columns in the
** using clause from the table on the right. */
continue;
}
}
pRight = sqlite3Expr(db, TK_ID, zName);
zColname = zName;
zToFree = 0;
if( longNames || pTabList->nSrc>1 ){
Expr *pLeft;
pLeft = sqlite3Expr(db, TK_ID, zTabName);
pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight);
if( zSchemaName ){
pLeft = sqlite3Expr(db, TK_ID, zSchemaName);
pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr);
}
if( longNames ){
zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName);
zToFree = zColname;
}
}else{
pExpr = pRight;
}
pNew = sqlite3ExprListAppend(pParse, pNew, pExpr);
sqlite3TokenInit(&sColname, zColname);
sqlite3ExprListSetName(pParse, pNew, &sColname, 0);
if( pNew && (p->selFlags & SF_NestedFrom)!=0 && !IN_RENAME_OBJECT ){
struct ExprList_item *pX = &pNew->a[pNew->nExpr-1];
sqlite3DbFree(db, pX->zEName);
if( pSub ){
pX->zEName = sqlite3DbStrDup(db, pSub->pEList->a[j].zEName);
testcase( pX->zEName==0 );
}else{
pX->zEName = sqlite3MPrintf(db, "%s.%s.%s",
zSchemaName, zTabName, zColname);
testcase( pX->zEName==0 );
}
pX->eEName = ENAME_TAB;
}
sqlite3DbFree(db, zToFree);
}
}
if( !tableSeen ){
if( zTName ){
sqlite3ErrorMsg(pParse, "no such table: %s", zTName);
}else{
sqlite3ErrorMsg(pParse, "no tables specified");
}
}
}
}
sqlite3ExprListDelete(db, pEList);
p->pEList = pNew;
}
if( p->pEList ){
if( p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
sqlite3ErrorMsg(pParse, "too many columns in result set");
return WRC_Abort;
}
if( (elistFlags & (EP_HasFunc|EP_Subquery))!=0 ){
p->selFlags |= SF_ComplexResult;
}
}
return WRC_Continue;
}
#if SQLITE_DEBUG
/*
** Always assert. This xSelectCallback2 implementation proves that the
** xSelectCallback2 is never invoked.
*/
SQLITE_PRIVATE void sqlite3SelectWalkAssert2(Walker *NotUsed, Select *NotUsed2){
UNUSED_PARAMETER2(NotUsed, NotUsed2);
assert( 0 );
}
#endif
/*
** This routine "expands" a SELECT statement and all of its subqueries.
** For additional information on what it means to "expand" a SELECT
** statement, see the comment on the selectExpand worker callback above.
**
** Expanding a SELECT statement is the first step in processing a
** SELECT statement. The SELECT statement must be expanded before
** name resolution is performed.
**
** If anything goes wrong, an error message is written into pParse.
** The calling function can detect the problem by looking at pParse->nErr
** and/or pParse->db->mallocFailed.
*/
static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
Walker w;
w.xExprCallback = sqlite3ExprWalkNoop;
w.pParse = pParse;
if( OK_IF_ALWAYS_TRUE(pParse->hasCompound) ){
w.xSelectCallback = convertCompoundSelectToSubquery;
w.xSelectCallback2 = 0;
sqlite3WalkSelect(&w, pSelect);
}
w.xSelectCallback = selectExpander;
w.xSelectCallback2 = selectPopWith;
w.eCode = 0;
sqlite3WalkSelect(&w, pSelect);
}
#ifndef SQLITE_OMIT_SUBQUERY
/*
** This is a Walker.xSelectCallback callback for the sqlite3SelectTypeInfo()
** interface.
**
** For each FROM-clause subquery, add Column.zType and Column.zColl
** information to the Table structure that represents the result set
** of that subquery.
**
** The Table structure that represents the result set was constructed
** by selectExpander() but the type and collation information was omitted
** at that point because identifiers had not yet been resolved. This
** routine is called after identifier resolution.
*/
static void selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){
Parse *pParse;
int i;
SrcList *pTabList;
struct SrcList_item *pFrom;
assert( p->selFlags & SF_Resolved );
if( p->selFlags & SF_HasTypeInfo ) return;
p->selFlags |= SF_HasTypeInfo;
pParse = pWalker->pParse;
pTabList = p->pSrc;
for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
Table *pTab = pFrom->pTab;
assert( pTab!=0 );
if( (pTab->tabFlags & TF_Ephemeral)!=0 ){
/* A sub-query in the FROM clause of a SELECT */
Select *pSel = pFrom->pSelect;
if( pSel ){
while( pSel->pPrior ) pSel = pSel->pPrior;
sqlite3SelectAddColumnTypeAndCollation(pParse, pTab, pSel,
SQLITE_AFF_NONE);
}
}
}
}
#endif
/*
** This routine adds datatype and collating sequence information to
** the Table structures of all FROM-clause subqueries in a
** SELECT statement.
**
** Use this routine after name resolution.
*/
static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){
#ifndef SQLITE_OMIT_SUBQUERY
Walker w;
w.xSelectCallback = sqlite3SelectWalkNoop;
w.xSelectCallback2 = selectAddSubqueryTypeInfo;
w.xExprCallback = sqlite3ExprWalkNoop;
w.pParse = pParse;
sqlite3WalkSelect(&w, pSelect);
#endif
}
/*
** This routine sets up a SELECT statement for processing. The
** following is accomplished:
**
** * VDBE Cursor numbers are assigned to all FROM-clause terms.
** * Ephemeral Table objects are created for all FROM-clause subqueries.
** * ON and USING clauses are shifted into WHERE statements
** * Wildcards "*" and "TABLE.*" in result sets are expanded.
** * Identifiers in expression are matched to tables.
**
** This routine acts recursively on all subqueries within the SELECT.
*/
SQLITE_PRIVATE void sqlite3SelectPrep(
Parse *pParse, /* The parser context */
Select *p, /* The SELECT statement being coded. */
NameContext *pOuterNC /* Name context for container */
){
assert( p!=0 || pParse->db->mallocFailed );
if( pParse->db->mallocFailed ) return;
if( p->selFlags & SF_HasTypeInfo ) return;
sqlite3SelectExpand(pParse, p);
if( pParse->nErr || pParse->db->mallocFailed ) return;
sqlite3ResolveSelectNames(pParse, p, pOuterNC);
if( pParse->nErr || pParse->db->mallocFailed ) return;
sqlite3SelectAddTypeInfo(pParse, p);
}
/*
** Reset the aggregate accumulator.
**
** The aggregate accumulator is a set of memory cells that hold
** intermediate results while calculating an aggregate. This
** routine generates code that stores NULLs in all of those memory
** cells.
*/
static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
Vdbe *v = pParse->pVdbe;
int i;
struct AggInfo_func *pFunc;
int nReg = pAggInfo->nFunc + pAggInfo->nColumn;
if( nReg==0 ) return;
if( pParse->nErr || pParse->db->mallocFailed ) return;
#ifdef SQLITE_DEBUG
/* Verify that all AggInfo registers are within the range specified by
** AggInfo.mnReg..AggInfo.mxReg */
assert( nReg==pAggInfo->mxReg-pAggInfo->mnReg+1 );
for(i=0; i<pAggInfo->nColumn; i++){
assert( pAggInfo->aCol[i].iMem>=pAggInfo->mnReg
&& pAggInfo->aCol[i].iMem<=pAggInfo->mxReg );
}
for(i=0; i<pAggInfo->nFunc; i++){
assert( pAggInfo->aFunc[i].iMem>=pAggInfo->mnReg
&& pAggInfo->aFunc[i].iMem<=pAggInfo->mxReg );
}
#endif
sqlite3VdbeAddOp3(v, OP_Null, 0, pAggInfo->mnReg, pAggInfo->mxReg);
for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
if( pFunc->iDistinct>=0 ){
Expr *pE = pFunc->pFExpr;
assert( !ExprHasProperty(pE, EP_xIsSelect) );
if( pE->x.pList==0 || pE->x.pList->nExpr!=1 ){
sqlite3ErrorMsg(pParse, "DISTINCT aggregates must have exactly one "
"argument");
pFunc->iDistinct = -1;
}else{
KeyInfo *pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pE->x.pList,0,0);
sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0,
(char*)pKeyInfo, P4_KEYINFO);
}
}
}
}
/*
** Invoke the OP_AggFinalize opcode for every aggregate function
** in the AggInfo structure.
*/
static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
Vdbe *v = pParse->pVdbe;
int i;
struct AggInfo_func *pF;
for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
ExprList *pList = pF->pFExpr->x.pList;
assert( !ExprHasProperty(pF->pFExpr, EP_xIsSelect) );
sqlite3VdbeAddOp2(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0);
sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);
}
}
/*
** Update the accumulator memory cells for an aggregate based on
** the current cursor position.
**
** If regAcc is non-zero and there are no min() or max() aggregates
** in pAggInfo, then only populate the pAggInfo->nAccumulator accumulator
** registers if register regAcc contains 0. The caller will take care
** of setting and clearing regAcc.
*/
static void updateAccumulator(Parse *pParse, int regAcc, AggInfo *pAggInfo){
Vdbe *v = pParse->pVdbe;
int i;
int regHit = 0;
int addrHitTest = 0;
struct AggInfo_func *pF;
struct AggInfo_col *pC;
pAggInfo->directMode = 1;
for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
int nArg;
int addrNext = 0;
int regAgg;
ExprList *pList = pF->pFExpr->x.pList;
assert( !ExprHasProperty(pF->pFExpr, EP_xIsSelect) );
assert( !IsWindowFunc(pF->pFExpr) );
if( ExprHasProperty(pF->pFExpr, EP_WinFunc) ){
Expr *pFilter = pF->pFExpr->y.pWin->pFilter;
if( pAggInfo->nAccumulator
&& (pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL)
&& regAcc
){
/* If regAcc==0, there there exists some min() or max() function
** without a FILTER clause that will ensure the magnet registers
** are populated. */
if( regHit==0 ) regHit = ++pParse->nMem;
/* If this is the first row of the group (regAcc contains 0), clear the
** "magnet" register regHit so that the accumulator registers
** are populated if the FILTER clause jumps over the the
** invocation of min() or max() altogether. Or, if this is not
** the first row (regAcc contains 1), set the magnet register so that
** the accumulators are not populated unless the min()/max() is invoked
** and indicates that they should be. */
sqlite3VdbeAddOp2(v, OP_Copy, regAcc, regHit);
}
addrNext = sqlite3VdbeMakeLabel(pParse);
sqlite3ExprIfFalse(pParse, pFilter, addrNext, SQLITE_JUMPIFNULL);
}
if( pList ){
nArg = pList->nExpr;
regAgg = sqlite3GetTempRange(pParse, nArg);
sqlite3ExprCodeExprList(pParse, pList, regAgg, 0, SQLITE_ECEL_DUP);
}else{
nArg = 0;
regAgg = 0;
}
if( pF->iDistinct>=0 ){
if( addrNext==0 ){
addrNext = sqlite3VdbeMakeLabel(pParse);
}
testcase( nArg==0 ); /* Error condition */
testcase( nArg>1 ); /* Also an error */
codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg);
}
if( pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){
CollSeq *pColl = 0;
struct ExprList_item *pItem;
int j;
assert( pList!=0 ); /* pList!=0 if pF->pFunc has NEEDCOLL */
for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
}
if( !pColl ){
pColl = pParse->db->pDfltColl;
}
if( regHit==0 && pAggInfo->nAccumulator ) regHit = ++pParse->nMem;
sqlite3VdbeAddOp4(v, OP_CollSeq, regHit, 0, 0, (char *)pColl, P4_COLLSEQ);
}
sqlite3VdbeAddOp3(v, OP_AggStep, 0, regAgg, pF->iMem);
sqlite3VdbeAppendP4(v, pF->pFunc, P4_FUNCDEF);
sqlite3VdbeChangeP5(v, (u8)nArg);
sqlite3ReleaseTempRange(pParse, regAgg, nArg);
if( addrNext ){
sqlite3VdbeResolveLabel(v, addrNext);
}
}
if( regHit==0 && pAggInfo->nAccumulator ){
regHit = regAcc;
}
if( regHit ){
addrHitTest = sqlite3VdbeAddOp1(v, OP_If, regHit); VdbeCoverage(v);
}
for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
sqlite3ExprCode(pParse, pC->pCExpr, pC->iMem);
}
pAggInfo->directMode = 0;
if( addrHitTest ){
sqlite3VdbeJumpHereOrPopInst(v, addrHitTest);
}
}
/*
** Add a single OP_Explain instruction to the VDBE to explain a simple
** count(*) query ("SELECT count(*) FROM pTab").
*/
#ifndef SQLITE_OMIT_EXPLAIN
static void explainSimpleCount(
Parse *pParse, /* Parse context */
Table *pTab, /* Table being queried */
Index *pIdx /* Index used to optimize scan, or NULL */
){
if( pParse->explain==2 ){
int bCover = (pIdx!=0 && (HasRowid(pTab) || !IsPrimaryKeyIndex(pIdx)));
sqlite3VdbeExplain(pParse, 0, "SCAN TABLE %s%s%s",
pTab->zName,
bCover ? " USING COVERING INDEX " : "",
bCover ? pIdx->zName : ""
);
}
}
#else
# define explainSimpleCount(a,b,c)
#endif
/*
** sqlite3WalkExpr() callback used by havingToWhere().
**
** If the node passed to the callback is a TK_AND node, return
** WRC_Continue to tell sqlite3WalkExpr() to iterate through child nodes.
**
** Otherwise, return WRC_Prune. In this case, also check if the
** sub-expression matches the criteria for being moved to the WHERE
** clause. If so, add it to the WHERE clause and replace the sub-expression
** within the HAVING expression with a constant "1".
*/
static int havingToWhereExprCb(Walker *pWalker, Expr *pExpr){
if( pExpr->op!=TK_AND ){
Select *pS = pWalker->u.pSelect;
if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, pS->pGroupBy)
&& ExprAlwaysFalse(pExpr)==0
){
sqlite3 *db = pWalker->pParse->db;
Expr *pNew = sqlite3Expr(db, TK_INTEGER, "1");
if( pNew ){
Expr *pWhere = pS->pWhere;
SWAP(Expr, *pNew, *pExpr);
pNew = sqlite3ExprAnd(pWalker->pParse, pWhere, pNew);
pS->pWhere = pNew;
pWalker->eCode = 1;
}
}
return WRC_Prune;
}
return WRC_Continue;
}
/*
** Transfer eligible terms from the HAVING clause of a query, which is
** processed after grouping, to the WHERE clause, which is processed before
** grouping. For example, the query:
**
** SELECT * FROM <tables> WHERE a=? GROUP BY b HAVING b=? AND c=?
**
** can be rewritten as:
**
** SELECT * FROM <tables> WHERE a=? AND b=? GROUP BY b HAVING c=?
**
** A term of the HAVING expression is eligible for transfer if it consists
** entirely of constants and expressions that are also GROUP BY terms that
** use the "BINARY" collation sequence.
*/
static void havingToWhere(Parse *pParse, Select *p){
Walker sWalker;
memset(&sWalker, 0, sizeof(sWalker));
sWalker.pParse = pParse;
sWalker.xExprCallback = havingToWhereExprCb;
sWalker.u.pSelect = p;
sqlite3WalkExpr(&sWalker, p->pHaving);
#if SELECTTRACE_ENABLED
if( sWalker.eCode && (sqlite3_unsupported_selecttrace & 0x100)!=0 ){
SELECTTRACE(0x100,pParse,p,("Move HAVING terms into WHERE:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
}
/*
** Check to see if the pThis entry of pTabList is a self-join of a prior view.
** If it is, then return the SrcList_item for the prior view. If it is not,
** then return 0.
*/
static struct SrcList_item *isSelfJoinView(
SrcList *pTabList, /* Search for self-joins in this FROM clause */
struct SrcList_item *pThis /* Search for prior reference to this subquery */
){
struct SrcList_item *pItem;
for(pItem = pTabList->a; pItem<pThis; pItem++){
Select *pS1;
if( pItem->pSelect==0 ) continue;
if( pItem->fg.viaCoroutine ) continue;
if( pItem->zName==0 ) continue;
assert( pItem->pTab!=0 );
assert( pThis->pTab!=0 );
if( pItem->pTab->pSchema!=pThis->pTab->pSchema ) continue;
if( sqlite3_stricmp(pItem->zName, pThis->zName)!=0 ) continue;
pS1 = pItem->pSelect;
if( pItem->pTab->pSchema==0 && pThis->pSelect->selId!=pS1->selId ){
/* The query flattener left two different CTE tables with identical
** names in the same FROM clause. */
continue;
}
if( sqlite3ExprCompare(0, pThis->pSelect->pWhere, pS1->pWhere, -1)
|| sqlite3ExprCompare(0, pThis->pSelect->pHaving, pS1->pHaving, -1)
){
/* The view was modified by some other optimization such as
** pushDownWhereTerms() */
continue;
}
return pItem;
}
return 0;
}
#ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION
/*
** Attempt to transform a query of the form
**
** SELECT count(*) FROM (SELECT x FROM t1 UNION ALL SELECT y FROM t2)
**
** Into this:
**
** SELECT (SELECT count(*) FROM t1)+(SELECT count(*) FROM t2)
**
** The transformation only works if all of the following are true:
**
** * The subquery is a UNION ALL of two or more terms
** * The subquery does not have a LIMIT clause
** * There is no WHERE or GROUP BY or HAVING clauses on the subqueries
** * The outer query is a simple count(*) with no WHERE clause or other
** extraneous syntax.
**
** Return TRUE if the optimization is undertaken.
*/
static int countOfViewOptimization(Parse *pParse, Select *p){
Select *pSub, *pPrior;
Expr *pExpr;
Expr *pCount;
sqlite3 *db;
if( (p->selFlags & SF_Aggregate)==0 ) return 0; /* This is an aggregate */
if( p->pEList->nExpr!=1 ) return 0; /* Single result column */
if( p->pWhere ) return 0;
if( p->pGroupBy ) return 0;
pExpr = p->pEList->a[0].pExpr;
if( pExpr->op!=TK_AGG_FUNCTION ) return 0; /* Result is an aggregate */
if( sqlite3_stricmp(pExpr->u.zToken,"count") ) return 0; /* Is count() */
if( pExpr->x.pList!=0 ) return 0; /* Must be count(*) */
if( p->pSrc->nSrc!=1 ) return 0; /* One table in FROM */
pSub = p->pSrc->a[0].pSelect;
if( pSub==0 ) return 0; /* The FROM is a subquery */
if( pSub->pPrior==0 ) return 0; /* Must be a compound ry */
do{
if( pSub->op!=TK_ALL && pSub->pPrior ) return 0; /* Must be UNION ALL */
if( pSub->pWhere ) return 0; /* No WHERE clause */
if( pSub->pLimit ) return 0; /* No LIMIT clause */
if( pSub->selFlags & SF_Aggregate ) return 0; /* Not an aggregate */
pSub = pSub->pPrior; /* Repeat over compound */
}while( pSub );
/* If we reach this point then it is OK to perform the transformation */
db = pParse->db;
pCount = pExpr;
pExpr = 0;
pSub = p->pSrc->a[0].pSelect;
p->pSrc->a[0].pSelect = 0;
sqlite3SrcListDelete(db, p->pSrc);
p->pSrc = sqlite3DbMallocZero(pParse->db, sizeof(*p->pSrc));
while( pSub ){
Expr *pTerm;
pPrior = pSub->pPrior;
pSub->pPrior = 0;
pSub->pNext = 0;
pSub->selFlags |= SF_Aggregate;
pSub->selFlags &= ~SF_Compound;
pSub->nSelectRow = 0;
sqlite3ExprListDelete(db, pSub->pEList);
pTerm = pPrior ? sqlite3ExprDup(db, pCount, 0) : pCount;
pSub->pEList = sqlite3ExprListAppend(pParse, 0, pTerm);
pTerm = sqlite3PExpr(pParse, TK_SELECT, 0, 0);
sqlite3PExprAddSelect(pParse, pTerm, pSub);
if( pExpr==0 ){
pExpr = pTerm;
}else{
pExpr = sqlite3PExpr(pParse, TK_PLUS, pTerm, pExpr);
}
pSub = pPrior;
}
p->pEList->a[0].pExpr = pExpr;
p->selFlags &= ~SF_Aggregate;
#if SELECTTRACE_ENABLED
if( sqlite3_unsupported_selecttrace & 0x400 ){
SELECTTRACE(0x400,pParse,p,("After count-of-view optimization:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
return 1;
}
#endif /* SQLITE_COUNTOFVIEW_OPTIMIZATION */
/*
** Generate code for the SELECT statement given in the p argument.
**
** The results are returned according to the SelectDest structure.
** See comments in sqliteInt.h for further information.
**
** This routine returns the number of errors. If any errors are
** encountered, then an appropriate error message is left in
** pParse->zErrMsg.
**
** This routine does NOT free the Select structure passed in. The
** calling function needs to do that.
*/
SQLITE_PRIVATE int sqlite3Select(
Parse *pParse, /* The parser context */
Select *p, /* The SELECT statement being coded. */
SelectDest *pDest /* What to do with the query results */
){
int i, j; /* Loop counters */
WhereInfo *pWInfo; /* Return from sqlite3WhereBegin() */
Vdbe *v; /* The virtual machine under construction */
int isAgg; /* True for select lists like "count(*)" */
ExprList *pEList = 0; /* List of columns to extract. */
SrcList *pTabList; /* List of tables to select from */
Expr *pWhere; /* The WHERE clause. May be NULL */
ExprList *pGroupBy; /* The GROUP BY clause. May be NULL */
Expr *pHaving; /* The HAVING clause. May be NULL */
AggInfo *pAggInfo = 0; /* Aggregate information */
int rc = 1; /* Value to return from this function */
DistinctCtx sDistinct; /* Info on how to code the DISTINCT keyword */
SortCtx sSort; /* Info on how to code the ORDER BY clause */
int iEnd; /* Address of the end of the query */
sqlite3 *db; /* The database connection */
ExprList *pMinMaxOrderBy = 0; /* Added ORDER BY for min/max queries */
u8 minMaxFlag; /* Flag for min/max queries */
db = pParse->db;
v = sqlite3GetVdbe(pParse);
if( p==0 || db->mallocFailed || pParse->nErr ){
return 1;
}
if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
#if SELECTTRACE_ENABLED
SELECTTRACE(1,pParse,p, ("begin processing:\n", pParse->addrExplain));
if( sqlite3_unsupported_selecttrace & 0x100 ){
sqlite3TreeViewSelect(0, p, 0);
}
#endif
assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistFifo );
assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );
assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );
assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );
if( IgnorableDistinct(pDest) ){
assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union ||
pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard ||
pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_DistFifo );
/* All of these destinations are also able to ignore the ORDER BY clause */
sqlite3ExprListDelete(db, p->pOrderBy);
p->pOrderBy = 0;
p->selFlags &= ~SF_Distinct;
p->selFlags |= SF_NoopOrderBy;
}
sqlite3SelectPrep(pParse, p, 0);
if( pParse->nErr || db->mallocFailed ){
goto select_end;
}
assert( p->pEList!=0 );
#if SELECTTRACE_ENABLED
if( sqlite3_unsupported_selecttrace & 0x104 ){
SELECTTRACE(0x104,pParse,p, ("after name resolution:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
/* If the SF_UpdateFrom flag is set, then this function is being called
** as part of populating the temp table for an UPDATE...FROM statement.
** In this case, it is an error if the target object (pSrc->a[0]) name
** or alias is duplicated within FROM clause (pSrc->a[1..n]). */
if( p->selFlags & SF_UpdateFrom ){
struct SrcList_item *p0 = &p->pSrc->a[0];
for(i=1; i<p->pSrc->nSrc; i++){
struct SrcList_item *p1 = &p->pSrc->a[i];
if( p0->pTab==p1->pTab && 0==sqlite3_stricmp(p0->zAlias, p1->zAlias) ){
sqlite3ErrorMsg(pParse,
"target object/alias may not appear in FROM clause: %s",
p0->zAlias ? p0->zAlias : p0->pTab->zName
);
goto select_end;
}
}
}
if( pDest->eDest==SRT_Output ){
generateColumnNames(pParse, p);
}
#ifndef SQLITE_OMIT_WINDOWFUNC
rc = sqlite3WindowRewrite(pParse, p);
if( rc ){
assert( db->mallocFailed || pParse->nErr>0 );
goto select_end;
}
#if SELECTTRACE_ENABLED
if( p->pWin && (sqlite3_unsupported_selecttrace & 0x108)!=0 ){
SELECTTRACE(0x104,pParse,p, ("after window rewrite:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
#endif /* SQLITE_OMIT_WINDOWFUNC */
pTabList = p->pSrc;
isAgg = (p->selFlags & SF_Aggregate)!=0;
memset(&sSort, 0, sizeof(sSort));
sSort.pOrderBy = p->pOrderBy;
/* Try to do various optimizations (flattening subqueries, and strength
** reduction of join operators) in the FROM clause up into the main query
*/
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
struct SrcList_item *pItem = &pTabList->a[i];
Select *pSub = pItem->pSelect;
Table *pTab = pItem->pTab;
/* The expander should have already created transient Table objects
** even for FROM clause elements such as subqueries that do not correspond
** to a real table */
assert( pTab!=0 );
/* Convert LEFT JOIN into JOIN if there are terms of the right table
** of the LEFT JOIN used in the WHERE clause.
*/
if( (pItem->fg.jointype & JT_LEFT)!=0
&& sqlite3ExprImpliesNonNullRow(p->pWhere, pItem->iCursor)
&& OptimizationEnabled(db, SQLITE_SimplifyJoin)
){
SELECTTRACE(0x100,pParse,p,
("LEFT-JOIN simplifies to JOIN on term %d\n",i));
pItem->fg.jointype &= ~(JT_LEFT|JT_OUTER);
unsetJoinExpr(p->pWhere, pItem->iCursor);
}
/* No futher action if this term of the FROM clause is no a subquery */
if( pSub==0 ) continue;
/* Catch mismatch in the declared columns of a view and the number of
** columns in the SELECT on the RHS */
if( pTab->nCol!=pSub->pEList->nExpr ){
sqlite3ErrorMsg(pParse, "expected %d columns for '%s' but got %d",
pTab->nCol, pTab->zName, pSub->pEList->nExpr);
goto select_end;
}
/* Do not try to flatten an aggregate subquery.
**
** Flattening an aggregate subquery is only possible if the outer query
** is not a join. But if the outer query is not a join, then the subquery
** will be implemented as a co-routine and there is no advantage to
** flattening in that case.
*/
if( (pSub->selFlags & SF_Aggregate)!=0 ) continue;
assert( pSub->pGroupBy==0 );
/* If the outer query contains a "complex" result set (that is,
** if the result set of the outer query uses functions or subqueries)
** and if the subquery contains an ORDER BY clause and if
** it will be implemented as a co-routine, then do not flatten. This
** restriction allows SQL constructs like this:
**
** SELECT expensive_function(x)
** FROM (SELECT x FROM tab ORDER BY y LIMIT 10);
**
** The expensive_function() is only computed on the 10 rows that
** are output, rather than every row of the table.
**
** The requirement that the outer query have a complex result set
** means that flattening does occur on simpler SQL constraints without
** the expensive_function() like:
**
** SELECT x FROM (SELECT x FROM tab ORDER BY y LIMIT 10);
*/
if( pSub->pOrderBy!=0
&& i==0
&& (p->selFlags & SF_ComplexResult)!=0
&& (pTabList->nSrc==1
|| (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)
){
continue;
}
if( flattenSubquery(pParse, p, i, isAgg) ){
if( pParse->nErr ) goto select_end;
/* This subquery can be absorbed into its parent. */
i = -1;
}
pTabList = p->pSrc;
if( db->mallocFailed ) goto select_end;
if( !IgnorableOrderby(pDest) ){
sSort.pOrderBy = p->pOrderBy;
}
}
#endif
#ifndef SQLITE_OMIT_COMPOUND_SELECT
/* Handle compound SELECT statements using the separate multiSelect()
** procedure.
*/
if( p->pPrior ){
rc = multiSelect(pParse, p, pDest);
#if SELECTTRACE_ENABLED
SELECTTRACE(0x1,pParse,p,("end compound-select processing\n"));
if( (sqlite3_unsupported_selecttrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
sqlite3TreeViewSelect(0, p, 0);
}
#endif
if( p->pNext==0 ) ExplainQueryPlanPop(pParse);
return rc;
}
#endif
/* Do the WHERE-clause constant propagation optimization if this is
** a join. No need to speed time on this operation for non-join queries
** as the equivalent optimization will be handled by query planner in
** sqlite3WhereBegin().
*/
if( pTabList->nSrc>1
&& OptimizationEnabled(db, SQLITE_PropagateConst)
&& propagateConstants(pParse, p)
){
#if SELECTTRACE_ENABLED
if( sqlite3_unsupported_selecttrace & 0x100 ){
SELECTTRACE(0x100,pParse,p,("After constant propagation:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
}else{
SELECTTRACE(0x100,pParse,p,("Constant propagation not helpful\n"));
}
#ifdef SQLITE_COUNTOFVIEW_OPTIMIZATION
if( OptimizationEnabled(db, SQLITE_QueryFlattener|SQLITE_CountOfView)
&& countOfViewOptimization(pParse, p)
){
if( db->mallocFailed ) goto select_end;
pEList = p->pEList;
pTabList = p->pSrc;
}
#endif
/* For each term in the FROM clause, do two things:
** (1) Authorized unreferenced tables
** (2) Generate code for all sub-queries
*/
for(i=0; i<pTabList->nSrc; i++){
struct SrcList_item *pItem = &pTabList->a[i];
SelectDest dest;
Select *pSub;
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
const char *zSavedAuthContext;
#endif
/* Issue SQLITE_READ authorizations with a fake column name for any
** tables that are referenced but from which no values are extracted.
** Examples of where these kinds of null SQLITE_READ authorizations
** would occur:
**
** SELECT count(*) FROM t1; -- SQLITE_READ t1.""
** SELECT t1.* FROM t1, t2; -- SQLITE_READ t2.""
**
** The fake column name is an empty string. It is possible for a table to
** have a column named by the empty string, in which case there is no way to
** distinguish between an unreferenced table and an actual reference to the
** "" column. The original design was for the fake column name to be a NULL,
** which would be unambiguous. But legacy authorization callbacks might
** assume the column name is non-NULL and segfault. The use of an empty
** string for the fake column name seems safer.
*/
if( pItem->colUsed==0 && pItem->zName!=0 ){
sqlite3AuthCheck(pParse, SQLITE_READ, pItem->zName, "", pItem->zDatabase);
}
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
/* Generate code for all sub-queries in the FROM clause
*/
pSub = pItem->pSelect;
if( pSub==0 ) continue;
/* The code for a subquery should only be generated once, though it is
** technically harmless for it to be generated multiple times. The
** following assert() will detect if something changes to cause
** the same subquery to be coded multiple times, as a signal to the
** developers to try to optimize the situation.
**
** Update 2019-07-24:
** See ticket https://sqlite.org/src/tktview/c52b09c7f38903b1311cec40.
** The dbsqlfuzz fuzzer found a case where the same subquery gets
** coded twice. So this assert() now becomes a testcase(). It should
** be very rare, though.
*/
testcase( pItem->addrFillSub!=0 );
/* Increment Parse.nHeight by the height of the largest expression
** tree referred to by this, the parent select. The child select
** may contain expression trees of at most
** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
** more conservative than necessary, but much easier than enforcing
** an exact limit.
*/
pParse->nHeight += sqlite3SelectExprHeight(p);
/* Make copies of constant WHERE-clause terms in the outer query down
** inside the subquery. This can help the subquery to run more efficiently.
*/
if( OptimizationEnabled(db, SQLITE_PushDown)
&& pushDownWhereTerms(pParse, pSub, p->pWhere, pItem->iCursor,
(pItem->fg.jointype & JT_OUTER)!=0)
){
#if SELECTTRACE_ENABLED
if( sqlite3_unsupported_selecttrace & 0x100 ){
SELECTTRACE(0x100,pParse,p,
("After WHERE-clause push-down into subquery %d:\n", pSub->selId));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
}else{
SELECTTRACE(0x100,pParse,p,("Push-down not possible\n"));
}
zSavedAuthContext = pParse->zAuthContext;
pParse->zAuthContext = pItem->zName;
/* Generate code to implement the subquery
**
** The subquery is implemented as a co-routine if the subquery is
** guaranteed to be the outer loop (so that it does not need to be
** computed more than once)
**
** TODO: Are there other reasons beside (1) to use a co-routine
** implementation?
*/
if( i==0
&& (pTabList->nSrc==1
|| (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0) /* (1) */
){
/* Implement a co-routine that will return a single row of the result
** set on each invocation.
*/
int addrTop = sqlite3VdbeCurrentAddr(v)+1;
pItem->regReturn = ++pParse->nMem;
sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
VdbeComment((v, "%s", pItem->pTab->zName));
pItem->addrFillSub = addrTop;
sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
ExplainQueryPlan((pParse, 1, "CO-ROUTINE %u", pSub->selId));
sqlite3Select(pParse, pSub, &dest);
pItem->pTab->nRowLogEst = pSub->nSelectRow;
pItem->fg.viaCoroutine = 1;
pItem->regResult = dest.iSdst;
sqlite3VdbeEndCoroutine(v, pItem->regReturn);
sqlite3VdbeJumpHere(v, addrTop-1);
sqlite3ClearTempRegCache(pParse);
}else{
/* Generate a subroutine that will fill an ephemeral table with
** the content of this subquery. pItem->addrFillSub will point
** to the address of the generated subroutine. pItem->regReturn
** is a register allocated to hold the subroutine return address
*/
int topAddr;
int onceAddr = 0;
int retAddr;
struct SrcList_item *pPrior;
testcase( pItem->addrFillSub==0 ); /* Ticket c52b09c7f38903b1311 */
pItem->regReturn = ++pParse->nMem;
topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
pItem->addrFillSub = topAddr+1;
if( pItem->fg.isCorrelated==0 ){
/* If the subquery is not correlated and if we are not inside of
** a trigger, then we only need to compute the value of the subquery
** once. */
onceAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
}else{
VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));
}
pPrior = isSelfJoinView(pTabList, pItem);
if( pPrior ){
sqlite3VdbeAddOp2(v, OP_OpenDup, pItem->iCursor, pPrior->iCursor);
assert( pPrior->pSelect!=0 );
pSub->nSelectRow = pPrior->pSelect->nSelectRow;
}else{
sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
ExplainQueryPlan((pParse, 1, "MATERIALIZE %u", pSub->selId));
sqlite3Select(pParse, pSub, &dest);
}
pItem->pTab->nRowLogEst = pSub->nSelectRow;
if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
VdbeComment((v, "end %s", pItem->pTab->zName));
sqlite3VdbeChangeP1(v, topAddr, retAddr);
sqlite3ClearTempRegCache(pParse);
}
if( db->mallocFailed ) goto select_end;
pParse->nHeight -= sqlite3SelectExprHeight(p);
pParse->zAuthContext = zSavedAuthContext;
#endif
}
/* Various elements of the SELECT copied into local variables for
** convenience */
pEList = p->pEList;
pWhere = p->pWhere;
pGroupBy = p->pGroupBy;
pHaving = p->pHaving;
sDistinct.isTnct = (p->selFlags & SF_Distinct)!=0;
#if SELECTTRACE_ENABLED
if( sqlite3_unsupported_selecttrace & 0x400 ){
SELECTTRACE(0x400,pParse,p,("After all FROM-clause analysis:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
/* If the query is DISTINCT with an ORDER BY but is not an aggregate, and
** if the select-list is the same as the ORDER BY list, then this query
** can be rewritten as a GROUP BY. In other words, this:
**
** SELECT DISTINCT xyz FROM ... ORDER BY xyz
**
** is transformed to:
**
** SELECT xyz FROM ... GROUP BY xyz ORDER BY xyz
**
** The second form is preferred as a single index (or temp-table) may be
** used for both the ORDER BY and DISTINCT processing. As originally
** written the query must use a temp-table for at least one of the ORDER
** BY and DISTINCT, and an index or separate temp-table for the other.
*/
if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct
&& sqlite3ExprListCompare(sSort.pOrderBy, pEList, -1)==0
#ifndef SQLITE_OMIT_WINDOWFUNC
&& p->pWin==0
#endif
){
p->selFlags &= ~SF_Distinct;
pGroupBy = p->pGroupBy = sqlite3ExprListDup(db, pEList, 0);
p->selFlags |= SF_Aggregate;
/* Notice that even thought SF_Distinct has been cleared from p->selFlags,
** the sDistinct.isTnct is still set. Hence, isTnct represents the
** original setting of the SF_Distinct flag, not the current setting */
assert( sDistinct.isTnct );
#if SELECTTRACE_ENABLED
if( sqlite3_unsupported_selecttrace & 0x400 ){
SELECTTRACE(0x400,pParse,p,("Transform DISTINCT into GROUP BY:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
}
/* If there is an ORDER BY clause, then create an ephemeral index to
** do the sorting. But this sorting ephemeral index might end up
** being unused if the data can be extracted in pre-sorted order.
** If that is the case, then the OP_OpenEphemeral instruction will be
** changed to an OP_Noop once we figure out that the sorting index is
** not needed. The sSort.addrSortIndex variable is used to facilitate
** that change.
*/
if( sSort.pOrderBy ){
KeyInfo *pKeyInfo;
pKeyInfo = sqlite3KeyInfoFromExprList(
pParse, sSort.pOrderBy, 0, pEList->nExpr);
sSort.iECursor = pParse->nTab++;
sSort.addrSortIndex =
sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
sSort.iECursor, sSort.pOrderBy->nExpr+1+pEList->nExpr, 0,
(char*)pKeyInfo, P4_KEYINFO
);
}else{
sSort.addrSortIndex = -1;
}
/* If the output is destined for a temporary table, open that table.
*/
if( pDest->eDest==SRT_EphemTab ){
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iSDParm, pEList->nExpr);
}
/* Set the limiter.
*/
iEnd = sqlite3VdbeMakeLabel(pParse);
if( (p->selFlags & SF_FixedLimit)==0 ){
p->nSelectRow = 320; /* 4 billion rows */
}
computeLimitRegisters(pParse, p, iEnd);
if( p->iLimit==0 && sSort.addrSortIndex>=0 ){
sqlite3VdbeChangeOpcode(v, sSort.addrSortIndex, OP_SorterOpen);
sSort.sortFlags |= SORTFLAG_UseSorter;
}
/* Open an ephemeral index to use for the distinct set.
*/
if( p->selFlags & SF_Distinct ){
sDistinct.tabTnct = pParse->nTab++;
sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
sDistinct.tabTnct, 0, 0,
(char*)sqlite3KeyInfoFromExprList(pParse, p->pEList,0,0),
P4_KEYINFO);
sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED;
}else{
sDistinct.eTnctType = WHERE_DISTINCT_NOOP;
}
if( !isAgg && pGroupBy==0 ){
/* No aggregate functions and no GROUP BY clause */
u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0)
| (p->selFlags & SF_FixedLimit);
#ifndef SQLITE_OMIT_WINDOWFUNC
Window *pWin = p->pWin; /* Main window object (or NULL) */
if( pWin ){
sqlite3WindowCodeInit(pParse, p);
}
#endif
assert( WHERE_USE_LIMIT==SF_FixedLimit );
/* Begin the database scan. */
SELECTTRACE(1,pParse,p,("WhereBegin\n"));
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy,
p->pEList, wctrlFlags, p->nSelectRow);
if( pWInfo==0 ) goto select_end;
if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
}
if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){
sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);
}
if( sSort.pOrderBy ){
sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo);
sSort.labelOBLopt = sqlite3WhereOrderByLimitOptLabel(pWInfo);
if( sSort.nOBSat==sSort.pOrderBy->nExpr ){
sSort.pOrderBy = 0;
}
}
/* If sorting index that was created by a prior OP_OpenEphemeral
** instruction ended up not being needed, then change the OP_OpenEphemeral
** into an OP_Noop.
*/
if( sSort.addrSortIndex>=0 && sSort.pOrderBy==0 ){
sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);
}
assert( p->pEList==pEList );
#ifndef SQLITE_OMIT_WINDOWFUNC
if( pWin ){
int addrGosub = sqlite3VdbeMakeLabel(pParse);
int iCont = sqlite3VdbeMakeLabel(pParse);
int iBreak = sqlite3VdbeMakeLabel(pParse);
int regGosub = ++pParse->nMem;
sqlite3WindowCodeStep(pParse, p, pWInfo, regGosub, addrGosub);
sqlite3VdbeAddOp2(v, OP_Goto, 0, iBreak);
sqlite3VdbeResolveLabel(v, addrGosub);
VdbeNoopComment((v, "inner-loop subroutine"));
sSort.labelOBLopt = 0;
selectInnerLoop(pParse, p, -1, &sSort, &sDistinct, pDest, iCont, iBreak);
sqlite3VdbeResolveLabel(v, iCont);
sqlite3VdbeAddOp1(v, OP_Return, regGosub);
VdbeComment((v, "end inner-loop subroutine"));
sqlite3VdbeResolveLabel(v, iBreak);
}else
#endif /* SQLITE_OMIT_WINDOWFUNC */
{
/* Use the standard inner loop. */
selectInnerLoop(pParse, p, -1, &sSort, &sDistinct, pDest,
sqlite3WhereContinueLabel(pWInfo),
sqlite3WhereBreakLabel(pWInfo));
/* End the database scan loop.
*/
sqlite3WhereEnd(pWInfo);
}
}else{
/* This case when there exist aggregate functions or a GROUP BY clause
** or both */
NameContext sNC; /* Name context for processing aggregate information */
int iAMem; /* First Mem address for storing current GROUP BY */
int iBMem; /* First Mem address for previous GROUP BY */
int iUseFlag; /* Mem address holding flag indicating that at least
** one row of the input to the aggregator has been
** processed */
int iAbortFlag; /* Mem address which causes query abort if positive */
int groupBySort; /* Rows come from source in GROUP BY order */
int addrEnd; /* End of processing for this SELECT */
int sortPTab = 0; /* Pseudotable used to decode sorting results */
int sortOut = 0; /* Output register from the sorter */
int orderByGrp = 0; /* True if the GROUP BY and ORDER BY are the same */
/* Remove any and all aliases between the result set and the
** GROUP BY clause.
*/
if( pGroupBy ){
int k; /* Loop counter */
struct ExprList_item *pItem; /* For looping over expression in a list */
for(k=p->pEList->nExpr, pItem=p->pEList->a; k>0; k--, pItem++){
pItem->u.x.iAlias = 0;
}
for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){
pItem->u.x.iAlias = 0;
}
assert( 66==sqlite3LogEst(100) );
if( p->nSelectRow>66 ) p->nSelectRow = 66;
/* If there is both a GROUP BY and an ORDER BY clause and they are
** identical, then it may be possible to disable the ORDER BY clause
** on the grounds that the GROUP BY will cause elements to come out
** in the correct order. It also may not - the GROUP BY might use a
** database index that causes rows to be grouped together as required
** but not actually sorted. Either way, record the fact that the
** ORDER BY and GROUP BY clauses are the same by setting the orderByGrp
** variable. */
if( sSort.pOrderBy && pGroupBy->nExpr==sSort.pOrderBy->nExpr ){
int ii;
/* The GROUP BY processing doesn't care whether rows are delivered in
** ASC or DESC order - only that each group is returned contiguously.
** So set the ASC/DESC flags in the GROUP BY to match those in the
** ORDER BY to maximize the chances of rows being delivered in an
** order that makes the ORDER BY redundant. */
for(ii=0; ii<pGroupBy->nExpr; ii++){
u8 sortFlags = sSort.pOrderBy->a[ii].sortFlags & KEYINFO_ORDER_DESC;
pGroupBy->a[ii].sortFlags = sortFlags;
}
if( sqlite3ExprListCompare(pGroupBy, sSort.pOrderBy, -1)==0 ){
orderByGrp = 1;
}
}
}else{
assert( 0==sqlite3LogEst(1) );
p->nSelectRow = 0;
}
/* Create a label to jump to when we want to abort the query */
addrEnd = sqlite3VdbeMakeLabel(pParse);
/* Convert TK_COLUMN nodes into TK_AGG_COLUMN and make entries in
** sAggInfo for all TK_AGG_FUNCTION nodes in expressions of the
** SELECT statement.
*/
pAggInfo = sqlite3DbMallocZero(db, sizeof(*pAggInfo) );
if( pAggInfo==0 ){
goto select_end;
}
pAggInfo->pNext = pParse->pAggList;
pParse->pAggList = pAggInfo;
pAggInfo->selId = p->selId;
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
sNC.uNC.pAggInfo = pAggInfo;
VVA_ONLY( sNC.ncFlags = NC_UAggInfo; )
pAggInfo->mnReg = pParse->nMem+1;
pAggInfo->nSortingColumn = pGroupBy ? pGroupBy->nExpr : 0;
pAggInfo->pGroupBy = pGroupBy;
sqlite3ExprAnalyzeAggList(&sNC, pEList);
sqlite3ExprAnalyzeAggList(&sNC, sSort.pOrderBy);
if( pHaving ){
if( pGroupBy ){
assert( pWhere==p->pWhere );
assert( pHaving==p->pHaving );
assert( pGroupBy==p->pGroupBy );
havingToWhere(pParse, p);
pWhere = p->pWhere;
}
sqlite3ExprAnalyzeAggregates(&sNC, pHaving);
}
pAggInfo->nAccumulator = pAggInfo->nColumn;
if( p->pGroupBy==0 && p->pHaving==0 && pAggInfo->nFunc==1 ){
minMaxFlag = minMaxQuery(db, pAggInfo->aFunc[0].pFExpr, &pMinMaxOrderBy);
}else{
minMaxFlag = WHERE_ORDERBY_NORMAL;
}
for(i=0; i<pAggInfo->nFunc; i++){
Expr *pExpr = pAggInfo->aFunc[i].pFExpr;
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
sNC.ncFlags |= NC_InAggFunc;
sqlite3ExprAnalyzeAggList(&sNC, pExpr->x.pList);
#ifndef SQLITE_OMIT_WINDOWFUNC
assert( !IsWindowFunc(pExpr) );
if( ExprHasProperty(pExpr, EP_WinFunc) ){
sqlite3ExprAnalyzeAggregates(&sNC, pExpr->y.pWin->pFilter);
}
#endif
sNC.ncFlags &= ~NC_InAggFunc;
}
pAggInfo->mxReg = pParse->nMem;
if( db->mallocFailed ) goto select_end;
#if SELECTTRACE_ENABLED
if( sqlite3_unsupported_selecttrace & 0x400 ){
int ii;
SELECTTRACE(0x400,pParse,p,("After aggregate analysis %p:\n", pAggInfo));
sqlite3TreeViewSelect(0, p, 0);
for(ii=0; ii<pAggInfo->nColumn; ii++){
sqlite3DebugPrintf("agg-column[%d] iMem=%d\n",
ii, pAggInfo->aCol[ii].iMem);
sqlite3TreeViewExpr(0, pAggInfo->aCol[ii].pCExpr, 0);
}
for(ii=0; ii<pAggInfo->nFunc; ii++){
sqlite3DebugPrintf("agg-func[%d]: iMem=%d\n",
ii, pAggInfo->aFunc[ii].iMem);
sqlite3TreeViewExpr(0, pAggInfo->aFunc[ii].pFExpr, 0);
}
}
#endif
/* Processing for aggregates with GROUP BY is very different and
** much more complex than aggregates without a GROUP BY.
*/
if( pGroupBy ){
KeyInfo *pKeyInfo; /* Keying information for the group by clause */
int addr1; /* A-vs-B comparision jump */
int addrOutputRow; /* Start of subroutine that outputs a result row */
int regOutputRow; /* Return address register for output subroutine */
int addrSetAbort; /* Set the abort flag and return */
int addrTopOfLoop; /* Top of the input loop */
int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */
int addrReset; /* Subroutine for resetting the accumulator */
int regReset; /* Return address register for reset subroutine */
/* If there is a GROUP BY clause we might need a sorting index to
** implement it. Allocate that sorting index now. If it turns out
** that we do not need it after all, the OP_SorterOpen instruction
** will be converted into a Noop.
*/
pAggInfo->sortingIdx = pParse->nTab++;
pKeyInfo = sqlite3KeyInfoFromExprList(pParse, pGroupBy,
0, pAggInfo->nColumn);
addrSortingIdx = sqlite3VdbeAddOp4(v, OP_SorterOpen,
pAggInfo->sortingIdx, pAggInfo->nSortingColumn,
0, (char*)pKeyInfo, P4_KEYINFO);
/* Initialize memory locations used by GROUP BY aggregate processing
*/
iUseFlag = ++pParse->nMem;
iAbortFlag = ++pParse->nMem;
regOutputRow = ++pParse->nMem;
addrOutputRow = sqlite3VdbeMakeLabel(pParse);
regReset = ++pParse->nMem;
addrReset = sqlite3VdbeMakeLabel(pParse);
iAMem = pParse->nMem + 1;
pParse->nMem += pGroupBy->nExpr;
iBMem = pParse->nMem + 1;
pParse->nMem += pGroupBy->nExpr;
sqlite3VdbeAddOp2(v, OP_Integer, 0, iAbortFlag);
VdbeComment((v, "clear abort flag"));
sqlite3VdbeAddOp3(v, OP_Null, 0, iAMem, iAMem+pGroupBy->nExpr-1);
/* Begin a loop that will extract all source rows in GROUP BY order.
** This might involve two separate loops with an OP_Sort in between, or
** it might be a single loop that uses an index to extract information
** in the right order to begin with.
*/
sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
SELECTTRACE(1,pParse,p,("WhereBegin\n"));
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0,
WHERE_GROUPBY | (orderByGrp ? WHERE_SORTBYGROUP : 0), 0
);
if( pWInfo==0 ) goto select_end;
if( sqlite3WhereIsOrdered(pWInfo)==pGroupBy->nExpr ){
/* The optimizer is able to deliver rows in group by order so
** we do not have to sort. The OP_OpenEphemeral table will be
** cancelled later because we still need to use the pKeyInfo
*/
groupBySort = 0;
}else{
/* Rows are coming out in undetermined order. We have to push
** each row into a sorting index, terminate the first loop,
** then loop over the sorting index in order to get the output
** in sorted order
*/
int regBase;
int regRecord;
int nCol;
int nGroupBy;
explainTempTable(pParse,
(sDistinct.isTnct && (p->selFlags&SF_Distinct)==0) ?
"DISTINCT" : "GROUP BY");
groupBySort = 1;
nGroupBy = pGroupBy->nExpr;
nCol = nGroupBy;
j = nGroupBy;
for(i=0; i<pAggInfo->nColumn; i++){
if( pAggInfo->aCol[i].iSorterColumn>=j ){
nCol++;
j++;
}
}
regBase = sqlite3GetTempRange(pParse, nCol);
sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0, 0);
j = nGroupBy;
for(i=0; i<pAggInfo->nColumn; i++){
struct AggInfo_col *pCol = &pAggInfo->aCol[i];
if( pCol->iSorterColumn>=j ){
int r1 = j + regBase;
sqlite3ExprCodeGetColumnOfTable(v,
pCol->pTab, pCol->iTable, pCol->iColumn, r1);
j++;
}
}
regRecord = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
sqlite3VdbeAddOp2(v, OP_SorterInsert, pAggInfo->sortingIdx, regRecord);
sqlite3ReleaseTempReg(pParse, regRecord);
sqlite3ReleaseTempRange(pParse, regBase, nCol);
sqlite3WhereEnd(pWInfo);
pAggInfo->sortingIdxPTab = sortPTab = pParse->nTab++;
sortOut = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp3(v, OP_OpenPseudo, sortPTab, sortOut, nCol);
sqlite3VdbeAddOp2(v, OP_SorterSort, pAggInfo->sortingIdx, addrEnd);
VdbeComment((v, "GROUP BY sort")); VdbeCoverage(v);
pAggInfo->useSortingIdx = 1;
}
/* If the index or temporary table used by the GROUP BY sort
** will naturally deliver rows in the order required by the ORDER BY
** clause, cancel the ephemeral table open coded earlier.
**
** This is an optimization - the correct answer should result regardless.
** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER to
** disable this optimization for testing purposes. */
if( orderByGrp && OptimizationEnabled(db, SQLITE_GroupByOrder)
&& (groupBySort || sqlite3WhereIsSorted(pWInfo))
){
sSort.pOrderBy = 0;
sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex);
}
/* Evaluate the current GROUP BY terms and store in b0, b1, b2...
** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
** Then compare the current GROUP BY terms against the GROUP BY terms
** from the previous row currently stored in a0, a1, a2...
*/
addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
if( groupBySort ){
sqlite3VdbeAddOp3(v, OP_SorterData, pAggInfo->sortingIdx,
sortOut, sortPTab);
}
for(j=0; j<pGroupBy->nExpr; j++){
if( groupBySort ){
sqlite3VdbeAddOp3(v, OP_Column, sortPTab, j, iBMem+j);
}else{
pAggInfo->directMode = 1;
sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j);
}
}
sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,
(char*)sqlite3KeyInfoRef(pKeyInfo), P4_KEYINFO);
addr1 = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp3(v, OP_Jump, addr1+1, 0, addr1+1); VdbeCoverage(v);
/* Generate code that runs whenever the GROUP BY changes.
** Changes in the GROUP BY are detected by the previous code
** block. If there were no changes, this block is skipped.
**
** This code copies current group by terms in b0,b1,b2,...
** over to a0,a1,a2. It then calls the output subroutine
** and resets the aggregate accumulator registers in preparation
** for the next GROUP BY batch.
*/
sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr);
sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
VdbeComment((v, "output one row"));
sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd); VdbeCoverage(v);
VdbeComment((v, "check abort flag"));
sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
VdbeComment((v, "reset accumulator"));
/* Update the aggregate accumulators based on the content of
** the current row
*/
sqlite3VdbeJumpHere(v, addr1);
updateAccumulator(pParse, iUseFlag, pAggInfo);
sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag);
VdbeComment((v, "indicate data in accumulator"));
/* End of the loop
*/
if( groupBySort ){
sqlite3VdbeAddOp2(v, OP_SorterNext, pAggInfo->sortingIdx, addrTopOfLoop);
VdbeCoverage(v);
}else{
sqlite3WhereEnd(pWInfo);
sqlite3VdbeChangeToNoop(v, addrSortingIdx);
}
/* Output the final row of result
*/
sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
VdbeComment((v, "output final row"));
/* Jump over the subroutines
*/
sqlite3VdbeGoto(v, addrEnd);
/* Generate a subroutine that outputs a single row of the result
** set. This subroutine first looks at the iUseFlag. If iUseFlag
** is less than or equal to zero, the subroutine is a no-op. If
** the processing calls for the query to abort, this subroutine
** increments the iAbortFlag memory location before returning in
** order to signal the caller to abort.
*/
addrSetAbort = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_Integer, 1, iAbortFlag);
VdbeComment((v, "set abort flag"));
sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
sqlite3VdbeResolveLabel(v, addrOutputRow);
addrOutputRow = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2);
VdbeCoverage(v);
VdbeComment((v, "Groupby result generator entry point"));
sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
finalizeAggFunctions(pParse, pAggInfo);
sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL);
selectInnerLoop(pParse, p, -1, &sSort,
&sDistinct, pDest,
addrOutputRow+1, addrSetAbort);
sqlite3VdbeAddOp1(v, OP_Return, regOutputRow);
VdbeComment((v, "end groupby result generator"));
/* Generate a subroutine that will reset the group-by accumulator
*/
sqlite3VdbeResolveLabel(v, addrReset);
resetAccumulator(pParse, pAggInfo);
sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag);
VdbeComment((v, "indicate accumulator empty"));
sqlite3VdbeAddOp1(v, OP_Return, regReset);
} /* endif pGroupBy. Begin aggregate queries without GROUP BY: */
else {
Table *pTab;
if( (pTab = isSimpleCount(p, pAggInfo))!=0 ){
/* If isSimpleCount() returns a pointer to a Table structure, then
** the SQL statement is of the form:
**
** SELECT count(*) FROM <tbl>
**
** where the Table structure returned represents table <tbl>.
**
** This statement is so common that it is optimized specially. The
** OP_Count instruction is executed either on the intkey table that
** contains the data for table <tbl> or on one of its indexes. It
** is better to execute the op on an index, as indexes are almost
** always spread across less pages than their corresponding tables.
*/
const int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
const int iCsr = pParse->nTab++; /* Cursor to scan b-tree */
Index *pIdx; /* Iterator variable */
KeyInfo *pKeyInfo = 0; /* Keyinfo for scanned index */
Index *pBest = 0; /* Best index found so far */
Pgno iRoot = pTab->tnum; /* Root page of scanned b-tree */
sqlite3CodeVerifySchema(pParse, iDb);
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
/* Search for the index that has the lowest scan cost.
**
** (2011-04-15) Do not do a full scan of an unordered index.
**
** (2013-10-03) Do not count the entries in a partial index.
**
** In practice the KeyInfo structure will not be used. It is only
** passed to keep OP_OpenRead happy.
*/
if( !HasRowid(pTab) ) pBest = sqlite3PrimaryKeyIndex(pTab);
if( !p->pSrc->a[0].fg.notIndexed ){
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( pIdx->bUnordered==0
&& pIdx->szIdxRow<pTab->szTabRow
&& pIdx->pPartIdxWhere==0
&& (!pBest || pIdx->szIdxRow<pBest->szIdxRow)
){
pBest = pIdx;
}
}
}
if( pBest ){
iRoot = pBest->tnum;
pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pBest);
}
/* Open a read-only cursor, execute the OP_Count, close the cursor. */
sqlite3VdbeAddOp4Int(v, OP_OpenRead, iCsr, (int)iRoot, iDb, 1);
if( pKeyInfo ){
sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO);
}
sqlite3VdbeAddOp2(v, OP_Count, iCsr, pAggInfo->aFunc[0].iMem);
sqlite3VdbeAddOp1(v, OP_Close, iCsr);
explainSimpleCount(pParse, pTab, pBest);
}else{
int regAcc = 0; /* "populate accumulators" flag */
int addrSkip;
/* If there are accumulator registers but no min() or max() functions
** without FILTER clauses, allocate register regAcc. Register regAcc
** will contain 0 the first time the inner loop runs, and 1 thereafter.
** The code generated by updateAccumulator() uses this to ensure
** that the accumulator registers are (a) updated only once if
** there are no min() or max functions or (b) always updated for the
** first row visited by the aggregate, so that they are updated at
** least once even if the FILTER clause means the min() or max()
** function visits zero rows. */
if( pAggInfo->nAccumulator ){
for(i=0; i<pAggInfo->nFunc; i++){
if( ExprHasProperty(pAggInfo->aFunc[i].pFExpr, EP_WinFunc) ){
continue;
}
if( pAggInfo->aFunc[i].pFunc->funcFlags&SQLITE_FUNC_NEEDCOLL ){
break;
}
}
if( i==pAggInfo->nFunc ){
regAcc = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regAcc);
}
}
/* This case runs if the aggregate has no GROUP BY clause. The
** processing is much simpler since there is only a single row
** of output.
*/
assert( p->pGroupBy==0 );
resetAccumulator(pParse, pAggInfo);
/* If this query is a candidate for the min/max optimization, then
** minMaxFlag will have been previously set to either
** WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX and pMinMaxOrderBy will
** be an appropriate ORDER BY expression for the optimization.
*/
assert( minMaxFlag==WHERE_ORDERBY_NORMAL || pMinMaxOrderBy!=0 );
assert( pMinMaxOrderBy==0 || pMinMaxOrderBy->nExpr==1 );
SELECTTRACE(1,pParse,p,("WhereBegin\n"));
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pMinMaxOrderBy,
0, minMaxFlag, 0);
if( pWInfo==0 ){
goto select_end;
}
updateAccumulator(pParse, regAcc, pAggInfo);
if( regAcc ) sqlite3VdbeAddOp2(v, OP_Integer, 1, regAcc);
addrSkip = sqlite3WhereOrderByLimitOptLabel(pWInfo);
if( addrSkip!=sqlite3WhereContinueLabel(pWInfo) ){
sqlite3VdbeGoto(v, addrSkip);
}
sqlite3WhereEnd(pWInfo);
finalizeAggFunctions(pParse, pAggInfo);
}
sSort.pOrderBy = 0;
sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL);
selectInnerLoop(pParse, p, -1, 0, 0,
pDest, addrEnd, addrEnd);
}
sqlite3VdbeResolveLabel(v, addrEnd);
} /* endif aggregate query */
if( sDistinct.eTnctType==WHERE_DISTINCT_UNORDERED ){
explainTempTable(pParse, "DISTINCT");
}
/* If there is an ORDER BY clause, then we need to sort the results
** and send them to the callback one by one.
*/
if( sSort.pOrderBy ){
explainTempTable(pParse,
sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY");
assert( p->pEList==pEList );
generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest);
}
/* Jump here to skip this query
*/
sqlite3VdbeResolveLabel(v, iEnd);
/* The SELECT has been coded. If there is an error in the Parse structure,
** set the return code to 1. Otherwise 0. */
rc = (pParse->nErr>0);
/* Control jumps to here if an error is encountered above, or upon
** successful coding of the SELECT.
*/
select_end:
sqlite3ExprListDelete(db, pMinMaxOrderBy);
#ifdef SQLITE_DEBUG
if( pAggInfo && !db->mallocFailed ){
for(i=0; i<pAggInfo->nColumn; i++){
Expr *pExpr = pAggInfo->aCol[i].pCExpr;
assert( pExpr!=0 || db->mallocFailed );
if( pExpr==0 ) continue;
assert( pExpr->pAggInfo==pAggInfo );
assert( pExpr->iAgg==i );
}
for(i=0; i<pAggInfo->nFunc; i++){
Expr *pExpr = pAggInfo->aFunc[i].pFExpr;
assert( pExpr!=0 || db->mallocFailed );
if( pExpr==0 ) continue;
assert( pExpr->pAggInfo==pAggInfo );
assert( pExpr->iAgg==i );
}
}
#endif
#if SELECTTRACE_ENABLED
SELECTTRACE(0x1,pParse,p,("end processing\n"));
if( (sqlite3_unsupported_selecttrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
sqlite3TreeViewSelect(0, p, 0);
}
#endif
ExplainQueryPlanPop(pParse);
return rc;
}
/************** End of select.c **********************************************/
/************** Begin file table.c *******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the sqlite3_get_table() and sqlite3_free_table()
** interface routines. These are just wrappers around the main
** interface routine of sqlite3_exec().
**
** These routines are in a separate files so that they will not be linked
** if they are not used.
*/
/* #include "sqliteInt.h" */
#ifndef SQLITE_OMIT_GET_TABLE
/*
** This structure is used to pass data from sqlite3_get_table() through
** to the callback function is uses to build the result.
*/
typedef struct TabResult {
char **azResult; /* Accumulated output */
char *zErrMsg; /* Error message text, if an error occurs */
u32 nAlloc; /* Slots allocated for azResult[] */
u32 nRow; /* Number of rows in the result */
u32 nColumn; /* Number of columns in the result */
u32 nData; /* Slots used in azResult[]. (nRow+1)*nColumn */
int rc; /* Return code from sqlite3_exec() */
} TabResult;
/*
** This routine is called once for each row in the result table. Its job
** is to fill in the TabResult structure appropriately, allocating new
** memory as necessary.
*/
static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
TabResult *p = (TabResult*)pArg; /* Result accumulator */
int need; /* Slots needed in p->azResult[] */
int i; /* Loop counter */
char *z; /* A single column of result */
/* Make sure there is enough space in p->azResult to hold everything
** we need to remember from this invocation of the callback.
*/
if( p->nRow==0 && argv!=0 ){
need = nCol*2;
}else{
need = nCol;
}
if( p->nData + need > p->nAlloc ){
char **azNew;
p->nAlloc = p->nAlloc*2 + need;
azNew = sqlite3Realloc( p->azResult, sizeof(char*)*p->nAlloc );
if( azNew==0 ) goto malloc_failed;
p->azResult = azNew;
}
/* If this is the first row, then generate an extra row containing
** the names of all columns.
*/
if( p->nRow==0 ){
p->nColumn = nCol;
for(i=0; i<nCol; i++){
z = sqlite3_mprintf("%s", colv[i]);
if( z==0 ) goto malloc_failed;
p->azResult[p->nData++] = z;
}
}else if( (int)p->nColumn!=nCol ){
sqlite3_free(p->zErrMsg);
p->zErrMsg = sqlite3_mprintf(
"sqlite3_get_table() called with two or more incompatible queries"
);
p->rc = SQLITE_ERROR;
return 1;
}
/* Copy over the row data
*/
if( argv!=0 ){
for(i=0; i<nCol; i++){
if( argv[i]==0 ){
z = 0;
}else{
int n = sqlite3Strlen30(argv[i])+1;
z = sqlite3_malloc64( n );
if( z==0 ) goto malloc_failed;
memcpy(z, argv[i], n);
}
p->azResult[p->nData++] = z;
}
p->nRow++;
}
return 0;
malloc_failed:
p->rc = SQLITE_NOMEM_BKPT;
return 1;
}
/*
** Query the database. But instead of invoking a callback for each row,
** malloc() for space to hold the result and return the entire results
** at the conclusion of the call.
**
** The result that is written to ***pazResult is held in memory obtained
** from malloc(). But the caller cannot free this memory directly.
** Instead, the entire table should be passed to sqlite3_free_table() when
** the calling procedure is finished using it.
*/
SQLITE_API int SQLITE_APICALL sqlite3_get_table(
sqlite3 *db, /* The database on which the SQL executes */
const char *zSql, /* The SQL to be executed */
char ***pazResult, /* Write the result table here */
int *pnRow, /* Write the number of rows in the result here */
int *pnColumn, /* Write the number of columns of result here */
char **pzErrMsg /* Write error messages here */
){
int rc;
TabResult res;
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) || pazResult==0 ) return SQLITE_MISUSE_BKPT;
#endif
*pazResult = 0;
if( pnColumn ) *pnColumn = 0;
if( pnRow ) *pnRow = 0;
if( pzErrMsg ) *pzErrMsg = 0;
res.zErrMsg = 0;
res.nRow = 0;
res.nColumn = 0;
res.nData = 1;
res.nAlloc = 20;
res.rc = SQLITE_OK;
res.azResult = sqlite3_malloc64(sizeof(char*)*res.nAlloc );
if( res.azResult==0 ){
db->errCode = SQLITE_NOMEM;
return SQLITE_NOMEM_BKPT;
}
res.azResult[0] = 0;
rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
assert( sizeof(res.azResult[0])>= sizeof(res.nData) );
res.azResult[0] = SQLITE_INT_TO_PTR(res.nData);
if( (rc&0xff)==SQLITE_ABORT ){
sqlite3_free_table(&res.azResult[1]);
if( res.zErrMsg ){
if( pzErrMsg ){
sqlite3_free(*pzErrMsg);
*pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);
}
sqlite3_free(res.zErrMsg);
}
db->errCode = res.rc; /* Assume 32-bit assignment is atomic */
return res.rc;
}
sqlite3_free(res.zErrMsg);
if( rc!=SQLITE_OK ){
sqlite3_free_table(&res.azResult[1]);
return rc;
}
if( res.nAlloc>res.nData ){
char **azNew;
azNew = sqlite3Realloc( res.azResult, sizeof(char*)*res.nData );
if( azNew==0 ){
sqlite3_free_table(&res.azResult[1]);
db->errCode = SQLITE_NOMEM;
return SQLITE_NOMEM_BKPT;
}
res.azResult = azNew;
}
*pazResult = &res.azResult[1];
if( pnColumn ) *pnColumn = res.nColumn;
if( pnRow ) *pnRow = res.nRow;
return rc;
}
/*
** This routine frees the space the sqlite3_get_table() malloced.
*/
SQLITE_API void SQLITE_APICALL sqlite3_free_table(
char **azResult /* Result returned from sqlite3_get_table() */
){
if( azResult ){
int i, n;
azResult--;
assert( azResult!=0 );
n = SQLITE_PTR_TO_INT(azResult[0]);
for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }
sqlite3_free(azResult);
}
}
#endif /* SQLITE_OMIT_GET_TABLE */
/************** End of table.c ***********************************************/
/************** Begin file trigger.c *****************************************/
/*
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation for TRIGGERs
*/
/* #include "sqliteInt.h" */
#ifndef SQLITE_OMIT_TRIGGER
/*
** Delete a linked list of TriggerStep structures.
*/
SQLITE_PRIVATE void sqlite3DeleteTriggerStep(sqlite3 *db, TriggerStep *pTriggerStep){
while( pTriggerStep ){
TriggerStep * pTmp = pTriggerStep;
pTriggerStep = pTriggerStep->pNext;
sqlite3ExprDelete(db, pTmp->pWhere);
sqlite3ExprListDelete(db, pTmp->pExprList);
sqlite3SelectDelete(db, pTmp->pSelect);
sqlite3IdListDelete(db, pTmp->pIdList);
sqlite3UpsertDelete(db, pTmp->pUpsert);
sqlite3SrcListDelete(db, pTmp->pFrom);
sqlite3DbFree(db, pTmp->zSpan);
sqlite3DbFree(db, pTmp);
}
}
/*
** Given table pTab, return a list of all the triggers attached to
** the table. The list is connected by Trigger.pNext pointers.
**
** All of the triggers on pTab that are in the same database as pTab
** are already attached to pTab->pTrigger. But there might be additional
** triggers on pTab in the TEMP schema. This routine prepends all
** TEMP triggers on pTab to the beginning of the pTab->pTrigger list
** and returns the combined list.
**
** To state it another way: This routine returns a list of all triggers
** that fire off of pTab. The list will include any TEMP triggers on
** pTab as well as the triggers lised in pTab->pTrigger.
*/
SQLITE_PRIVATE Trigger *sqlite3TriggerList(Parse *pParse, Table *pTab){
Schema * const pTmpSchema = pParse->db->aDb[1].pSchema;
Trigger *pList = 0; /* List of triggers to return */
if( pParse->disableTriggers ){
return 0;
}
if( pTmpSchema!=pTab->pSchema ){
HashElem *p;
assert( sqlite3SchemaMutexHeld(pParse->db, 0, pTmpSchema) );
for(p=sqliteHashFirst(&pTmpSchema->trigHash); p; p=sqliteHashNext(p)){
Trigger *pTrig = (Trigger *)sqliteHashData(p);
if( pTrig->pTabSchema==pTab->pSchema
&& 0==sqlite3StrICmp(pTrig->table, pTab->zName)
){
pTrig->pNext = (pList ? pList : pTab->pTrigger);
pList = pTrig;
}
}
}
return (pList ? pList : pTab->pTrigger);
}
/*
** This is called by the parser when it sees a CREATE TRIGGER statement
** up to the point of the BEGIN before the trigger actions. A Trigger
** structure is generated based on the information available and stored
** in pParse->pNewTrigger. After the trigger actions have been parsed, the
** sqlite3FinishTrigger() function is called to complete the trigger
** construction process.
*/
SQLITE_PRIVATE void sqlite3BeginTrigger(
Parse *pParse, /* The parse context of the CREATE TRIGGER statement */
Token *pName1, /* The name of the trigger */
Token *pName2, /* The name of the trigger */
int tr_tm, /* One of TK_BEFORE, TK_AFTER, TK_INSTEAD */
int op, /* One of TK_INSERT, TK_UPDATE, TK_DELETE */
IdList *pColumns, /* column list if this is an UPDATE OF trigger */
SrcList *pTableName,/* The name of the table/view the trigger applies to */
Expr *pWhen, /* WHEN clause */
int isTemp, /* True if the TEMPORARY keyword is present */
int noErr /* Suppress errors if the trigger already exists */
){
Trigger *pTrigger = 0; /* The new trigger */
Table *pTab; /* Table that the trigger fires off of */
char *zName = 0; /* Name of the trigger */
sqlite3 *db = pParse->db; /* The database connection */
int iDb; /* The database to store the trigger in */
Token *pName; /* The unqualified db name */
DbFixer sFix; /* State vector for the DB fixer */
assert( pName1!=0 ); /* pName1->z might be NULL, but not pName1 itself */
assert( pName2!=0 );
assert( op==TK_INSERT || op==TK_UPDATE || op==TK_DELETE );
assert( op>0 && op<0xff );
if( isTemp ){
/* If TEMP was specified, then the trigger name may not be qualified. */
if( pName2->n>0 ){
sqlite3ErrorMsg(pParse, "temporary trigger may not have qualified name");
goto trigger_cleanup;
}
iDb = 1;
pName = pName1;
}else{
/* Figure out the db that the trigger will be created in */
iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pName);
if( iDb<0 ){
goto trigger_cleanup;
}
}
if( !pTableName || db->mallocFailed ){
goto trigger_cleanup;
}
/* A long-standing parser bug is that this syntax was allowed:
**
** CREATE TRIGGER attached.demo AFTER INSERT ON attached.tab ....
** ^^^^^^^^
**
** To maintain backwards compatibility, ignore the database
** name on pTableName if we are reparsing out of the schema table
*/
if( db->init.busy && iDb!=1 ){
sqlite3DbFree(db, pTableName->a[0].zDatabase);
pTableName->a[0].zDatabase = 0;
}
/* If the trigger name was unqualified, and the table is a temp table,
** then set iDb to 1 to create the trigger in the temporary database.
** If sqlite3SrcListLookup() returns 0, indicating the table does not
** exist, the error is caught by the block below.
*/
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( db->init.busy==0 && pName2->n==0 && pTab
&& pTab->pSchema==db->aDb[1].pSchema ){
iDb = 1;
}
/* Ensure the table name matches database name and that the table exists */
if( db->mallocFailed ) goto trigger_cleanup;
assert( pTableName->nSrc==1 );
sqlite3FixInit(&sFix, pParse, iDb, "trigger", pName);
if( sqlite3FixSrcList(&sFix, pTableName) ){
goto trigger_cleanup;
}
pTab = sqlite3SrcListLookup(pParse, pTableName);
if( !pTab ){
/* The table does not exist. */
goto trigger_orphan_error;
}
if( IsVirtual(pTab) ){
sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");
goto trigger_orphan_error;
}
/* Check that the trigger name is not reserved and that no trigger of the
** specified name exists */
zName = sqlite3NameFromToken(db, pName);
if( zName==0 ){
assert( db->mallocFailed );
goto trigger_cleanup;
}
if( sqlite3CheckObjectName(pParse, zName, "trigger", pTab->zName) ){
goto trigger_cleanup;
}
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
if( !IN_RENAME_OBJECT ){
if( sqlite3HashFind(&(db->aDb[iDb].pSchema->trigHash),zName) ){
if( !noErr ){
sqlite3ErrorMsg(pParse, "trigger %T already exists", pName);
}else{
assert( !db->init.busy );
sqlite3CodeVerifySchema(pParse, iDb);
}
goto trigger_cleanup;
}
}
/* Do not create a trigger on a system table */
if( sqlite3StrNICmp(pTab->zName, "sqlite_", 7)==0 ){
sqlite3ErrorMsg(pParse, "cannot create trigger on system table");
goto trigger_cleanup;
}
/* INSTEAD of triggers are only for views and views only support INSTEAD
** of triggers.
*/
if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S",
(tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
goto trigger_orphan_error;
}
if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
" trigger on table: %S", pTableName, 0);
goto trigger_orphan_error;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
if( !IN_RENAME_OBJECT ){
int iTabDb = sqlite3SchemaToIndex(db, pTab->pSchema);
int code = SQLITE_CREATE_TRIGGER;
const char *zDb = db->aDb[iTabDb].zDbSName;
const char *zDbTrig = isTemp ? db->aDb[1].zDbSName : zDb;
if( iTabDb==1 || isTemp ) code = SQLITE_CREATE_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, zName, pTab->zName, zDbTrig) ){
goto trigger_cleanup;
}
if( sqlite3AuthCheck(pParse, SQLITE_INSERT, SCHEMA_TABLE(iTabDb),0,zDb)){
goto trigger_cleanup;
}
}
#endif
/* INSTEAD OF triggers can only appear on views and BEFORE triggers
** cannot appear on views. So we might as well translate every
** INSTEAD OF trigger into a BEFORE trigger. It simplifies code
** elsewhere.
*/
if (tr_tm == TK_INSTEAD){
tr_tm = TK_BEFORE;
}
/* Build the Trigger object */
pTrigger = (Trigger*)sqlite3DbMallocZero(db, sizeof(Trigger));
if( pTrigger==0 ) goto trigger_cleanup;
pTrigger->zName = zName;
zName = 0;
pTrigger->table = sqlite3DbStrDup(db, pTableName->a[0].zName);
pTrigger->pSchema = db->aDb[iDb].pSchema;
pTrigger->pTabSchema = pTab->pSchema;
pTrigger->op = (u8)op;
pTrigger->tr_tm = tr_tm==TK_BEFORE ? TRIGGER_BEFORE : TRIGGER_AFTER;
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenRemap(pParse, pTrigger->table, pTableName->a[0].zName);
pTrigger->pWhen = pWhen;
pWhen = 0;
}else{
pTrigger->pWhen = sqlite3ExprDup(db, pWhen, EXPRDUP_REDUCE);
}
pTrigger->pColumns = pColumns;
pColumns = 0;
assert( pParse->pNewTrigger==0 );
pParse->pNewTrigger = pTrigger;
trigger_cleanup:
sqlite3DbFree(db, zName);
sqlite3SrcListDelete(db, pTableName);
sqlite3IdListDelete(db, pColumns);
sqlite3ExprDelete(db, pWhen);
if( !pParse->pNewTrigger ){
sqlite3DeleteTrigger(db, pTrigger);
}else{
assert( pParse->pNewTrigger==pTrigger );
}
return;
trigger_orphan_error:
if( db->init.iDb==1 ){
/* Ticket #3810.
** Normally, whenever a table is dropped, all associated triggers are
** dropped too. But if a TEMP trigger is created on a non-TEMP table
** and the table is dropped by a different database connection, the
** trigger is not visible to the database connection that does the
** drop so the trigger cannot be dropped. This results in an
** "orphaned trigger" - a trigger whose associated table is missing.
**
** 2020-11-05 see also https://sqlite.org/forum/forumpost/157dc791df
*/
db->init.orphanTrigger = 1;
}
goto trigger_cleanup;
}
/*
** This routine is called after all of the trigger actions have been parsed
** in order to complete the process of building the trigger.
*/
SQLITE_PRIVATE void sqlite3FinishTrigger(
Parse *pParse, /* Parser context */
TriggerStep *pStepList, /* The triggered program */
Token *pAll /* Token that describes the complete CREATE TRIGGER */
){
Trigger *pTrig = pParse->pNewTrigger; /* Trigger being finished */
char *zName; /* Name of trigger */
sqlite3 *db = pParse->db; /* The database */
DbFixer sFix; /* Fixer object */
int iDb; /* Database containing the trigger */
Token nameToken; /* Trigger name for error reporting */
pParse->pNewTrigger = 0;
if( NEVER(pParse->nErr) || !pTrig ) goto triggerfinish_cleanup;
zName = pTrig->zName;
iDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
pTrig->step_list = pStepList;
while( pStepList ){
pStepList->pTrig = pTrig;
pStepList = pStepList->pNext;
}
sqlite3TokenInit(&nameToken, pTrig->zName);
sqlite3FixInit(&sFix, pParse, iDb, "trigger", &nameToken);
if( sqlite3FixTriggerStep(&sFix, pTrig->step_list)
|| sqlite3FixExpr(&sFix, pTrig->pWhen)
){
goto triggerfinish_cleanup;
}
#ifndef SQLITE_OMIT_ALTERTABLE
if( IN_RENAME_OBJECT ){
assert( !db->init.busy );
pParse->pNewTrigger = pTrig;
pTrig = 0;
}else
#endif
/* if we are not initializing,
** build the sqlite_schema entry
*/
if( !db->init.busy ){
Vdbe *v;
char *z;
/* Make an entry in the sqlite_schema table */
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto triggerfinish_cleanup;
sqlite3BeginWriteOperation(pParse, 0, iDb);
z = sqlite3DbStrNDup(db, (char*)pAll->z, pAll->n);
testcase( z==0 );
sqlite3NestedParse(pParse,
"INSERT INTO %Q." DFLT_SCHEMA_TABLE
" VALUES('trigger',%Q,%Q,0,'CREATE TRIGGER %q')",
db->aDb[iDb].zDbSName, zName,
pTrig->table, z);
sqlite3DbFree(db, z);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddParseSchemaOp(v, iDb,
sqlite3MPrintf(db, "type='trigger' AND name='%q'", zName));
}
if( db->init.busy ){
Trigger *pLink = pTrig;
Hash *pHash = &db->aDb[iDb].pSchema->trigHash;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
assert( pLink!=0 );
pTrig = sqlite3HashInsert(pHash, zName, pTrig);
if( pTrig ){
sqlite3OomFault(db);
}else if( pLink->pSchema==pLink->pTabSchema ){
Table *pTab;
pTab = sqlite3HashFind(&pLink->pTabSchema->tblHash, pLink->table);
assert( pTab!=0 );
pLink->pNext = pTab->pTrigger;
pTab->pTrigger = pLink;
}
}
triggerfinish_cleanup:
sqlite3DeleteTrigger(db, pTrig);
assert( IN_RENAME_OBJECT || !pParse->pNewTrigger );
sqlite3DeleteTriggerStep(db, pStepList);
}
/*
** Duplicate a range of text from an SQL statement, then convert all
** whitespace characters into ordinary space characters.
*/
static char *triggerSpanDup(sqlite3 *db, const char *zStart, const char *zEnd){
char *z = sqlite3DbSpanDup(db, zStart, zEnd);
int i;
if( z ) for(i=0; z[i]; i++) if( sqlite3Isspace(z[i]) ) z[i] = ' ';
return z;
}
/*
** Turn a SELECT statement (that the pSelect parameter points to) into
** a trigger step. Return a pointer to a TriggerStep structure.
**
** The parser calls this routine when it finds a SELECT statement in
** body of a TRIGGER.
*/
SQLITE_PRIVATE TriggerStep *sqlite3TriggerSelectStep(
sqlite3 *db, /* Database connection */
Select *pSelect, /* The SELECT statement */
const char *zStart, /* Start of SQL text */
const char *zEnd /* End of SQL text */
){
TriggerStep *pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep));
if( pTriggerStep==0 ) {
sqlite3SelectDelete(db, pSelect);
return 0;
}
pTriggerStep->op = TK_SELECT;
pTriggerStep->pSelect = pSelect;
pTriggerStep->orconf = OE_Default;
pTriggerStep->zSpan = triggerSpanDup(db, zStart, zEnd);
return pTriggerStep;
}
/*
** Allocate space to hold a new trigger step. The allocated space
** holds both the TriggerStep object and the TriggerStep.target.z string.
**
** If an OOM error occurs, NULL is returned and db->mallocFailed is set.
*/
static TriggerStep *triggerStepAllocate(
Parse *pParse, /* Parser context */
u8 op, /* Trigger opcode */
Token *pName, /* The target name */
const char *zStart, /* Start of SQL text */
const char *zEnd /* End of SQL text */
){
sqlite3 *db = pParse->db;
TriggerStep *pTriggerStep;
pTriggerStep = sqlite3DbMallocZero(db, sizeof(TriggerStep) + pName->n + 1);
if( pTriggerStep ){
char *z = (char*)&pTriggerStep[1];
memcpy(z, pName->z, pName->n);
sqlite3Dequote(z);
pTriggerStep->zTarget = z;
pTriggerStep->op = op;
pTriggerStep->zSpan = triggerSpanDup(db, zStart, zEnd);
if( IN_RENAME_OBJECT ){
sqlite3RenameTokenMap(pParse, pTriggerStep->zTarget, pName);
}
}
return pTriggerStep;
}
/*
** Build a trigger step out of an INSERT statement. Return a pointer
** to the new trigger step.
**
** The parser calls this routine when it sees an INSERT inside the
** body of a trigger.
*/
SQLITE_PRIVATE TriggerStep *sqlite3TriggerInsertStep(
Parse *pParse, /* Parser */
Token *pTableName, /* Name of the table into which we insert */
IdList *pColumn, /* List of columns in pTableName to insert into */
Select *pSelect, /* A SELECT statement that supplies values */
u8 orconf, /* The conflict algorithm (OE_Abort, OE_Replace, etc.) */
Upsert *pUpsert, /* ON CONFLICT clauses for upsert */
const char *zStart, /* Start of SQL text */
const char *zEnd /* End of SQL text */
){
sqlite3 *db = pParse->db;
TriggerStep *pTriggerStep;
assert(pSelect != 0 || db->mallocFailed);
pTriggerStep = triggerStepAllocate(pParse, TK_INSERT, pTableName,zStart,zEnd);
if( pTriggerStep ){
if( IN_RENAME_OBJECT ){
pTriggerStep->pSelect = pSelect;
pSelect = 0;
}else{
pTriggerStep->pSelect = sqlite3SelectDup(db, pSelect, EXPRDUP_REDUCE);
}
pTriggerStep->pIdList = pColumn;
pTriggerStep->pUpsert = pUpsert;
pTriggerStep->orconf = orconf;
if( pUpsert ){
sqlite3HasExplicitNulls(pParse, pUpsert->pUpsertTarget);
}
}else{
testcase( pColumn );
sqlite3IdListDelete(db, pColumn);
testcase( pUpsert );
sqlite3UpsertDelete(db, pUpsert);
}
sqlite3SelectDelete(db, pSelect);
return pTriggerStep;
}
/*
** Construct a trigger step that implements an UPDATE statement and return
** a pointer to that trigger step. The parser calls this routine when it
** sees an UPDATE statement inside the body of a CREATE TRIGGER.
*/
SQLITE_PRIVATE TriggerStep *sqlite3TriggerUpdateStep(
Parse *pParse, /* Parser */
Token *pTableName, /* Name of the table to be updated */
SrcList *pFrom,
ExprList *pEList, /* The SET clause: list of column and new values */
Expr *pWhere, /* The WHERE clause */
u8 orconf, /* The conflict algorithm. (OE_Abort, OE_Ignore, etc) */
const char *zStart, /* Start of SQL text */
const char *zEnd /* End of SQL text */
){
sqlite3 *db = pParse->db;
TriggerStep *pTriggerStep;
pTriggerStep = triggerStepAllocate(pParse, TK_UPDATE, pTableName,zStart,zEnd);
if( pTriggerStep ){
if( IN_RENAME_OBJECT ){
pTriggerStep->pExprList = pEList;
pTriggerStep->pWhere = pWhere;
pTriggerStep->pFrom = pFrom;
pEList = 0;
pWhere = 0;
pFrom = 0;
}else{
pTriggerStep->pExprList = sqlite3ExprListDup(db, pEList, EXPRDUP_REDUCE);
pTriggerStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
pTriggerStep->pFrom = sqlite3SrcListDup(db, pFrom, EXPRDUP_REDUCE);
}
pTriggerStep->orconf = orconf;
}
sqlite3ExprListDelete(db, pEList);
sqlite3ExprDelete(db, pWhere);
sqlite3SrcListDelete(db, pFrom);
return pTriggerStep;
}
/*
** Construct a trigger step that implements a DELETE statement and return
** a pointer to that trigger step. The parser calls this routine when it
** sees a DELETE statement inside the body of a CREATE TRIGGER.
*/
SQLITE_PRIVATE TriggerStep *sqlite3TriggerDeleteStep(
Parse *pParse, /* Parser */
Token *pTableName, /* The table from which rows are deleted */
Expr *pWhere, /* The WHERE clause */
const char *zStart, /* Start of SQL text */
const char *zEnd /* End of SQL text */
){
sqlite3 *db = pParse->db;
TriggerStep *pTriggerStep;
pTriggerStep = triggerStepAllocate(pParse, TK_DELETE, pTableName,zStart,zEnd);
if( pTriggerStep ){
if( IN_RENAME_OBJECT ){
pTriggerStep->pWhere = pWhere;
pWhere = 0;
}else{
pTriggerStep->pWhere = sqlite3ExprDup(db, pWhere, EXPRDUP_REDUCE);
}
pTriggerStep->orconf = OE_Default;
}
sqlite3ExprDelete(db, pWhere);
return pTriggerStep;
}
/*
** Recursively delete a Trigger structure
*/
SQLITE_PRIVATE void sqlite3DeleteTrigger(sqlite3 *db, Trigger *pTrigger){
if( pTrigger==0 ) return;
sqlite3DeleteTriggerStep(db, pTrigger->step_list);
sqlite3DbFree(db, pTrigger->zName);
sqlite3DbFree(db, pTrigger->table);
sqlite3ExprDelete(db, pTrigger->pWhen);
sqlite3IdListDelete(db, pTrigger->pColumns);
sqlite3DbFree(db, pTrigger);
}
/*
** This function is called to drop a trigger from the database schema.
**
** This may be called directly from the parser and therefore identifies
** the trigger by name. The sqlite3DropTriggerPtr() routine does the
** same job as this routine except it takes a pointer to the trigger
** instead of the trigger name.
**/
SQLITE_PRIVATE void sqlite3DropTrigger(Parse *pParse, SrcList *pName, int noErr){
Trigger *pTrigger = 0;
int i;
const char *zDb;
const char *zName;
sqlite3 *db = pParse->db;
if( db->mallocFailed ) goto drop_trigger_cleanup;
if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
goto drop_trigger_cleanup;
}
assert( pName->nSrc==1 );
zDb = pName->a[0].zDatabase;
zName = pName->a[0].zName;
assert( zDb!=0 || sqlite3BtreeHoldsAllMutexes(db) );
for(i=OMIT_TEMPDB; i<db->nDb; i++){
int j = (i<2) ? i^1 : i; /* Search TEMP before MAIN */
if( zDb && sqlite3DbIsNamed(db, j, zDb)==0 ) continue;
assert( sqlite3SchemaMutexHeld(db, j, 0) );
pTrigger = sqlite3HashFind(&(db->aDb[j].pSchema->trigHash), zName);
if( pTrigger ) break;
}
if( !pTrigger ){
if( !noErr ){
sqlite3ErrorMsg(pParse, "no such trigger: %S", pName, 0);
}else{
sqlite3CodeVerifyNamedSchema(pParse, zDb);
}
pParse->checkSchema = 1;
goto drop_trigger_cleanup;
}
sqlite3DropTriggerPtr(pParse, pTrigger);
drop_trigger_cleanup:
sqlite3SrcListDelete(db, pName);
}
/*
** Return a pointer to the Table structure for the table that a trigger
** is set on.
*/
static Table *tableOfTrigger(Trigger *pTrigger){
return sqlite3HashFind(&pTrigger->pTabSchema->tblHash, pTrigger->table);
}
/*
** Drop a trigger given a pointer to that trigger.
*/
SQLITE_PRIVATE void sqlite3DropTriggerPtr(Parse *pParse, Trigger *pTrigger){
Table *pTable;
Vdbe *v;
sqlite3 *db = pParse->db;
int iDb;
iDb = sqlite3SchemaToIndex(pParse->db, pTrigger->pSchema);
assert( iDb>=0 && iDb<db->nDb );
pTable = tableOfTrigger(pTrigger);
assert( (pTable && pTable->pSchema==pTrigger->pSchema) || iDb==1 );
#ifndef SQLITE_OMIT_AUTHORIZATION
if( pTable ){
int code = SQLITE_DROP_TRIGGER;
const char *zDb = db->aDb[iDb].zDbSName;
const char *zTab = SCHEMA_TABLE(iDb);
if( iDb==1 ) code = SQLITE_DROP_TEMP_TRIGGER;
if( sqlite3AuthCheck(pParse, code, pTrigger->zName, pTable->zName, zDb) ||
sqlite3AuthCheck(pParse, SQLITE_DELETE, zTab, 0, zDb) ){
return;
}
}
#endif
/* Generate code to destroy the database record of the trigger.
*/
if( (v = sqlite3GetVdbe(pParse))!=0 ){
sqlite3NestedParse(pParse,
"DELETE FROM %Q." DFLT_SCHEMA_TABLE " WHERE name=%Q AND type='trigger'",
db->aDb[iDb].zDbSName, pTrigger->zName
);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->zName, 0);
}
}
/*
** Remove a trigger from the hash tables of the sqlite* pointer.
*/
SQLITE_PRIVATE void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){
Trigger *pTrigger;
Hash *pHash;
assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
pHash = &(db->aDb[iDb].pSchema->trigHash);
pTrigger = sqlite3HashInsert(pHash, zName, 0);
if( ALWAYS(pTrigger) ){
if( pTrigger->pSchema==pTrigger->pTabSchema ){
Table *pTab = tableOfTrigger(pTrigger);
if( pTab ){
Trigger **pp;
for(pp=&pTab->pTrigger; *pp; pp=&((*pp)->pNext)){
if( *pp==pTrigger ){
*pp = (*pp)->pNext;
break;
}
}
}
}
sqlite3DeleteTrigger(db, pTrigger);
db->mDbFlags |= DBFLAG_SchemaChange;
}
}
/*
** pEList is the SET clause of an UPDATE statement. Each entry
** in pEList is of the format <id>=<expr>. If any of the entries
** in pEList have an <id> which matches an identifier in pIdList,
** then return TRUE. If pIdList==NULL, then it is considered a
** wildcard that matches anything. Likewise if pEList==NULL then
** it matches anything so always return true. Return false only
** if there is no match.
*/
static int checkColumnOverlap(IdList *pIdList, ExprList *pEList){
int e;
if( pIdList==0 || NEVER(pEList==0) ) return 1;
for(e=0; e<pEList->nExpr; e++){
if( sqlite3IdListIndex(pIdList, pEList->a[e].zEName)>=0 ) return 1;
}
return 0;
}
/*
** Return a list of all triggers on table pTab if there exists at least
** one trigger that must be fired when an operation of type 'op' is
** performed on the table, and, if that operation is an UPDATE, if at
** least one of the columns in pChanges is being modified.
*/
SQLITE_PRIVATE Trigger *sqlite3TriggersExist(
Parse *pParse, /* Parse context */
Table *pTab, /* The table the contains the triggers */
int op, /* one of TK_DELETE, TK_INSERT, TK_UPDATE */
ExprList *pChanges, /* Columns that change in an UPDATE statement */
int *pMask /* OUT: Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
){
int mask = 0;
Trigger *pList = 0;
Trigger *p;
if( (pParse->db->flags & SQLITE_EnableTrigger)!=0 ){
pList = sqlite3TriggerList(pParse, pTab);
}
assert( pList==0 || IsVirtual(pTab)==0 );
for(p=pList; p; p=p->pNext){
if( p->op==op && checkColumnOverlap(p->pColumns, pChanges) ){
mask |= p->tr_tm;
}
}
if( pMask ){
*pMask = mask;
}
return (mask ? pList : 0);
}
/*
** Convert the pStep->zTarget string into a SrcList and return a pointer
** to that SrcList.
**
** This routine adds a specific database name, if needed, to the target when
** forming the SrcList. This prevents a trigger in one database from
** referring to a target in another database. An exception is when the
** trigger is in TEMP in which case it can refer to any other database it
** wants.
*/
SQLITE_PRIVATE SrcList *sqlite3TriggerStepSrc(
Parse *pParse, /* The parsing context */
TriggerStep *pStep /* The trigger containing the target token */
){
sqlite3 *db = pParse->db;
SrcList *pSrc; /* SrcList to be returned */
char *zName = sqlite3DbStrDup(db, pStep->zTarget);
pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
assert( pSrc==0 || pSrc->nSrc==1 );
assert( zName || pSrc==0 );
if( pSrc ){
Schema *pSchema = pStep->pTrig->pSchema;
pSrc->a[0].zName = zName;
if( pSchema!=db->aDb[1].pSchema ){
pSrc->a[0].pSchema = pSchema;
}
if( pStep->pFrom ){
SrcList *pDup = sqlite3SrcListDup(db, pStep->pFrom, 0);
pSrc = sqlite3SrcListAppendList(pParse, pSrc, pDup);
}
}else{
sqlite3DbFree(db, zName);
}
return pSrc;
}
/*
** Generate VDBE code for the statements inside the body of a single
** trigger.
*/
static int codeTriggerProgram(
Parse *pParse, /* The parser context */
TriggerStep *pStepList, /* List of statements inside the trigger body */
int orconf /* Conflict algorithm. (OE_Abort, etc) */
){
TriggerStep *pStep;
Vdbe *v = pParse->pVdbe;
sqlite3 *db = pParse->db;
assert( pParse->pTriggerTab && pParse->pToplevel );
assert( pStepList );
assert( v!=0 );
for(pStep=pStepList; pStep; pStep=pStep->pNext){
/* Figure out the ON CONFLICT policy that will be used for this step
** of the trigger program. If the statement that caused this trigger
** to fire had an explicit ON CONFLICT, then use it. Otherwise, use
** the ON CONFLICT policy that was specified as part of the trigger
** step statement. Example:
**
** CREATE TRIGGER AFTER INSERT ON t1 BEGIN;
** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b);
** END;
**
** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy
** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy
*/
pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf;
assert( pParse->okConstFactor==0 );
#ifndef SQLITE_OMIT_TRACE
if( pStep->zSpan ){
sqlite3VdbeAddOp4(v, OP_Trace, 0x7fffffff, 1, 0,
sqlite3MPrintf(db, "-- %s", pStep->zSpan),
P4_DYNAMIC);
}
#endif
switch( pStep->op ){
case TK_UPDATE: {
sqlite3Update(pParse,
sqlite3TriggerStepSrc(pParse, pStep),
sqlite3ExprListDup(db, pStep->pExprList, 0),
sqlite3ExprDup(db, pStep->pWhere, 0),
pParse->eOrconf, 0, 0, 0
);
break;
}
case TK_INSERT: {
sqlite3Insert(pParse,
sqlite3TriggerStepSrc(pParse, pStep),
sqlite3SelectDup(db, pStep->pSelect, 0),
sqlite3IdListDup(db, pStep->pIdList),
pParse->eOrconf,
sqlite3UpsertDup(db, pStep->pUpsert)
);
break;
}
case TK_DELETE: {
sqlite3DeleteFrom(pParse,
sqlite3TriggerStepSrc(pParse, pStep),
sqlite3ExprDup(db, pStep->pWhere, 0), 0, 0
);
break;
}
default: assert( pStep->op==TK_SELECT ); {
SelectDest sDest;
Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0);
sqlite3SelectDestInit(&sDest, SRT_Discard, 0);
sqlite3Select(pParse, pSelect, &sDest);
sqlite3SelectDelete(db, pSelect);
break;
}
}
if( pStep->op!=TK_SELECT ){
sqlite3VdbeAddOp0(v, OP_ResetCount);
}
}
return 0;
}
#ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
/*
** This function is used to add VdbeComment() annotations to a VDBE
** program. It is not used in production code, only for debugging.
*/
static const char *onErrorText(int onError){
switch( onError ){
case OE_Abort: return "abort";
case OE_Rollback: return "rollback";
case OE_Fail: return "fail";
case OE_Replace: return "replace";
case OE_Ignore: return "ignore";
case OE_Default: return "default";
}
return "n/a";
}
#endif
/*
** Parse context structure pFrom has just been used to create a sub-vdbe
** (trigger program). If an error has occurred, transfer error information
** from pFrom to pTo.
*/
static void transferParseError(Parse *pTo, Parse *pFrom){
assert( pFrom->zErrMsg==0 || pFrom->nErr );
assert( pTo->zErrMsg==0 || pTo->nErr );
if( pTo->nErr==0 ){
pTo->zErrMsg = pFrom->zErrMsg;
pTo->nErr = pFrom->nErr;
pTo->rc = pFrom->rc;
}else{
sqlite3DbFree(pFrom->db, pFrom->zErrMsg);
}
}
/*
** Create and populate a new TriggerPrg object with a sub-program
** implementing trigger pTrigger with ON CONFLICT policy orconf.
*/
static TriggerPrg *codeRowTrigger(
Parse *pParse, /* Current parse context */
Trigger *pTrigger, /* Trigger to code */
Table *pTab, /* The table pTrigger is attached to */
int orconf /* ON CONFLICT policy to code trigger program with */
){
Parse *pTop = sqlite3ParseToplevel(pParse);
sqlite3 *db = pParse->db; /* Database handle */
TriggerPrg *pPrg; /* Value to return */
Expr *pWhen = 0; /* Duplicate of trigger WHEN expression */
Vdbe *v; /* Temporary VM */
NameContext sNC; /* Name context for sub-vdbe */
SubProgram *pProgram = 0; /* Sub-vdbe for trigger program */
Parse *pSubParse; /* Parse context for sub-vdbe */
int iEndTrigger = 0; /* Label to jump to if WHEN is false */
assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );
assert( pTop->pVdbe );
/* Allocate the TriggerPrg and SubProgram objects. To ensure that they
** are freed if an error occurs, link them into the Parse.pTriggerPrg
** list of the top-level Parse object sooner rather than later. */
pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg));
if( !pPrg ) return 0;
pPrg->pNext = pTop->pTriggerPrg;
pTop->pTriggerPrg = pPrg;
pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram));
if( !pProgram ) return 0;
sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram);
pPrg->pTrigger = pTrigger;
pPrg->orconf = orconf;
pPrg->aColmask[0] = 0xffffffff;
pPrg->aColmask[1] = 0xffffffff;
/* Allocate and populate a new Parse context to use for coding the
** trigger sub-program. */
pSubParse = sqlite3StackAllocZero(db, sizeof(Parse));
if( !pSubParse ) return 0;
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pSubParse;
pSubParse->db = db;
pSubParse->pTriggerTab = pTab;
pSubParse->pToplevel = pTop;
pSubParse->zAuthContext = pTrigger->zName;
pSubParse->eTriggerOp = pTrigger->op;
pSubParse->nQueryLoop = pParse->nQueryLoop;
pSubParse->disableVtab = pParse->disableVtab;
v = sqlite3GetVdbe(pSubParse);
if( v ){
VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)",
pTrigger->zName, onErrorText(orconf),
(pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"),
(pTrigger->op==TK_UPDATE ? "UPDATE" : ""),
(pTrigger->op==TK_INSERT ? "INSERT" : ""),
(pTrigger->op==TK_DELETE ? "DELETE" : ""),
pTab->zName
));
#ifndef SQLITE_OMIT_TRACE
if( pTrigger->zName ){
sqlite3VdbeChangeP4(v, -1,
sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC
);
}
#endif
/* If one was specified, code the WHEN clause. If it evaluates to false
** (or NULL) the sub-vdbe is immediately halted by jumping to the
** OP_Halt inserted at the end of the program. */
if( pTrigger->pWhen ){
pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0);
if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen)
&& db->mallocFailed==0
){
iEndTrigger = sqlite3VdbeMakeLabel(pSubParse);
sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL);
}
sqlite3ExprDelete(db, pWhen);
}
/* Code the trigger program into the sub-vdbe. */
codeTriggerProgram(pSubParse, pTrigger->step_list, orconf);
/* Insert an OP_Halt at the end of the sub-program. */
if( iEndTrigger ){
sqlite3VdbeResolveLabel(v, iEndTrigger);
}
sqlite3VdbeAddOp0(v, OP_Halt);
VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf)));
transferParseError(pParse, pSubParse);
if( db->mallocFailed==0 && pParse->nErr==0 ){
pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg);
}
pProgram->nMem = pSubParse->nMem;
pProgram->nCsr = pSubParse->nTab;
pProgram->token = (void *)pTrigger;
pPrg->aColmask[0] = pSubParse->oldmask;
pPrg->aColmask[1] = pSubParse->newmask;
sqlite3VdbeDelete(v);
}
assert( !pSubParse->pAinc && !pSubParse->pZombieTab );
assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg );
sqlite3ParserReset(pSubParse);
sqlite3StackFree(db, pSubParse);
return pPrg;
}
/*
** Return a pointer to a TriggerPrg object containing the sub-program for
** trigger pTrigger with default ON CONFLICT algorithm orconf. If no such
** TriggerPrg object exists, a new object is allocated and populated before
** being returned.
*/
static TriggerPrg *getRowTrigger(
Parse *pParse, /* Current parse context */
Trigger *pTrigger, /* Trigger to code */
Table *pTab, /* The table trigger pTrigger is attached to */
int orconf /* ON CONFLICT algorithm. */
){
Parse *pRoot = sqlite3ParseToplevel(pParse);
TriggerPrg *pPrg;
assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) );
/* It may be that this trigger has already been coded (or is in the
** process of being coded). If this is the case, then an entry with
** a matching TriggerPrg.pTrigger field will be present somewhere
** in the Parse.pTriggerPrg list. Search for such an entry. */
for(pPrg=pRoot->pTriggerPrg;
pPrg && (pPrg->pTrigger!=pTrigger || pPrg->orconf!=orconf);
pPrg=pPrg->pNext
);
/* If an existing TriggerPrg could not be located, create a new one. */
if( !pPrg ){
pPrg = codeRowTrigger(pParse, pTrigger, pTab, orconf);
}
return pPrg;
}
/*
** Generate code for the trigger program associated with trigger p on
** table pTab. The reg, orconf and ignoreJump parameters passed to this
** function are the same as those described in the header function for
** sqlite3CodeRowTrigger()
*/
SQLITE_PRIVATE void sqlite3CodeRowTriggerDirect(
Parse *pParse, /* Parse context */
Trigger *p, /* Trigger to code */
Table *pTab, /* The table to code triggers from */
int reg, /* Reg array containing OLD.* and NEW.* values */
int orconf, /* ON CONFLICT policy */
int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */
){
Vdbe *v = sqlite3GetVdbe(pParse); /* Main VM */
TriggerPrg *pPrg;
pPrg = getRowTrigger(pParse, p, pTab, orconf);
assert( pPrg || pParse->nErr || pParse->db->mallocFailed );
/* Code the OP_Program opcode in the parent VDBE. P4 of the OP_Program
** is a pointer to the sub-vdbe containing the trigger program. */
if( pPrg ){
int bRecursive = (p->zName && 0==(pParse->db->flags&SQLITE_RecTriggers));
sqlite3VdbeAddOp4(v, OP_Program, reg, ignoreJump, ++pParse->nMem,
(const char *)pPrg->pProgram, P4_SUBPROGRAM);
VdbeComment(
(v, "Call: %s.%s", (p->zName?p->zName:"fkey"), onErrorText(orconf)));
/* Set the P5 operand of the OP_Program instruction to non-zero if
** recursive invocation of this trigger program is disallowed. Recursive
** invocation is disallowed if (a) the sub-program is really a trigger,
** not a foreign key action, and (b) the flag to enable recursive triggers
** is clear. */
sqlite3VdbeChangeP5(v, (u8)bRecursive);
}
}
/*
** This is called to code the required FOR EACH ROW triggers for an operation
** on table pTab. The operation to code triggers for (INSERT, UPDATE or DELETE)
** is given by the op parameter. The tr_tm parameter determines whether the
** BEFORE or AFTER triggers are coded. If the operation is an UPDATE, then
** parameter pChanges is passed the list of columns being modified.
**
** If there are no triggers that fire at the specified time for the specified
** operation on pTab, this function is a no-op.
**
** The reg argument is the address of the first in an array of registers
** that contain the values substituted for the new.* and old.* references
** in the trigger program. If N is the number of columns in table pTab
** (a copy of pTab->nCol), then registers are populated as follows:
**
** Register Contains
** ------------------------------------------------------
** reg+0 OLD.rowid
** reg+1 OLD.* value of left-most column of pTab
** ... ...
** reg+N OLD.* value of right-most column of pTab
** reg+N+1 NEW.rowid
** reg+N+2 OLD.* value of left-most column of pTab
** ... ...
** reg+N+N+1 NEW.* value of right-most column of pTab
**
** For ON DELETE triggers, the registers containing the NEW.* values will
** never be accessed by the trigger program, so they are not allocated or
** populated by the caller (there is no data to populate them with anyway).
** Similarly, for ON INSERT triggers the values stored in the OLD.* registers
** are never accessed, and so are not allocated by the caller. So, for an
** ON INSERT trigger, the value passed to this function as parameter reg
** is not a readable register, although registers (reg+N) through
** (reg+N+N+1) are.
**
** Parameter orconf is the default conflict resolution algorithm for the
** trigger program to use (REPLACE, IGNORE etc.). Parameter ignoreJump
** is the instruction that control should jump to if a trigger program
** raises an IGNORE exception.
*/
SQLITE_PRIVATE void sqlite3CodeRowTrigger(
Parse *pParse, /* Parse context */
Trigger *pTrigger, /* List of triggers on table pTab */
int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */
ExprList *pChanges, /* Changes list for any UPDATE OF triggers */
int tr_tm, /* One of TRIGGER_BEFORE, TRIGGER_AFTER */
Table *pTab, /* The table to code triggers from */
int reg, /* The first in an array of registers (see above) */
int orconf, /* ON CONFLICT policy */
int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */
){
Trigger *p; /* Used to iterate through pTrigger list */
assert( op==TK_UPDATE || op==TK_INSERT || op==TK_DELETE );
assert( tr_tm==TRIGGER_BEFORE || tr_tm==TRIGGER_AFTER );
assert( (op==TK_UPDATE)==(pChanges!=0) );
for(p=pTrigger; p; p=p->pNext){
/* Sanity checking: The schema for the trigger and for the table are
** always defined. The trigger must be in the same schema as the table
** or else it must be a TEMP trigger. */
assert( p->pSchema!=0 );
assert( p->pTabSchema!=0 );
assert( p->pSchema==p->pTabSchema
|| p->pSchema==pParse->db->aDb[1].pSchema );
/* Determine whether we should code this trigger */
if( p->op==op
&& p->tr_tm==tr_tm
&& checkColumnOverlap(p->pColumns, pChanges)
){
sqlite3CodeRowTriggerDirect(pParse, p, pTab, reg, orconf, ignoreJump);
}
}
}
/*
** Triggers may access values stored in the old.* or new.* pseudo-table.
** This function returns a 32-bit bitmask indicating which columns of the
** old.* or new.* tables actually are used by triggers. This information
** may be used by the caller, for example, to avoid having to load the entire
** old.* record into memory when executing an UPDATE or DELETE command.
**
** Bit 0 of the returned mask is set if the left-most column of the
** table may be accessed using an [old|new].<col> reference. Bit 1 is set if
** the second leftmost column value is required, and so on. If there
** are more than 32 columns in the table, and at least one of the columns
** with an index greater than 32 may be accessed, 0xffffffff is returned.
**
** It is not possible to determine if the old.rowid or new.rowid column is
** accessed by triggers. The caller must always assume that it is.
**
** Parameter isNew must be either 1 or 0. If it is 0, then the mask returned
** applies to the old.* table. If 1, the new.* table.
**
** Parameter tr_tm must be a mask with one or both of the TRIGGER_BEFORE
** and TRIGGER_AFTER bits set. Values accessed by BEFORE triggers are only
** included in the returned mask if the TRIGGER_BEFORE bit is set in the
** tr_tm parameter. Similarly, values accessed by AFTER triggers are only
** included in the returned mask if the TRIGGER_AFTER bit is set in tr_tm.
*/
SQLITE_PRIVATE u32 sqlite3TriggerColmask(
Parse *pParse, /* Parse context */
Trigger *pTrigger, /* List of triggers on table pTab */
ExprList *pChanges, /* Changes list for any UPDATE OF triggers */
int isNew, /* 1 for new.* ref mask, 0 for old.* ref mask */
int tr_tm, /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
Table *pTab, /* The table to code triggers from */
int orconf /* Default ON CONFLICT policy for trigger steps */
){
const int op = pChanges ? TK_UPDATE : TK_DELETE;
u32 mask = 0;
Trigger *p;
assert( isNew==1 || isNew==0 );
for(p=pTrigger; p; p=p->pNext){
if( p->op==op && (tr_tm&p->tr_tm)
&& checkColumnOverlap(p->pColumns,pChanges)
){
TriggerPrg *pPrg;
pPrg = getRowTrigger(pParse, p, pTab, orconf);
if( pPrg ){
mask |= pPrg->aColmask[isNew];
}
}
}
return mask;
}
#endif /* !defined(SQLITE_OMIT_TRIGGER) */
/************** End of trigger.c *********************************************/
/************** Begin file update.c ******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
*/
/* #include "sqliteInt.h" */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
Parse *pParse, /* The parsing context */
SrcList *pSrc, /* The virtual table to be modified */
Table *pTab, /* The virtual table */
ExprList *pChanges, /* The columns to change in the UPDATE statement */
Expr *pRowidExpr, /* Expression used to recompute the rowid */
int *aXRef, /* Mapping from columns of pTab to entries in pChanges */
Expr *pWhere, /* WHERE clause of the UPDATE statement */
int onError /* ON CONFLICT strategy */
);
#endif /* SQLITE_OMIT_VIRTUALTABLE */
/*
** The most recently coded instruction was an OP_Column to retrieve the
** i-th column of table pTab. This routine sets the P4 parameter of the
** OP_Column to the default value, if any.
**
** The default value of a column is specified by a DEFAULT clause in the
** column definition. This was either supplied by the user when the table
** was created, or added later to the table definition by an ALTER TABLE
** command. If the latter, then the row-records in the table btree on disk
** may not contain a value for the column and the default value, taken
** from the P4 parameter of the OP_Column instruction, is returned instead.
** If the former, then all row-records are guaranteed to include a value
** for the column and the P4 value is not required.
**
** Column definitions created by an ALTER TABLE command may only have
** literal default values specified: a number, null or a string. (If a more
** complicated default expression value was provided, it is evaluated
** when the ALTER TABLE is executed and one of the literal values written
** into the sqlite_schema table.)
**
** Therefore, the P4 parameter is only required if the default value for
** the column is a literal number, string or null. The sqlite3ValueFromExpr()
** function is capable of transforming these types of expressions into
** sqlite3_value objects.
**
** If column as REAL affinity and the table is an ordinary b-tree table
** (not a virtual table) then the value might have been stored as an
** integer. In that case, add an OP_RealAffinity opcode to make sure
** it has been converted into REAL.
*/
SQLITE_PRIVATE void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){
assert( pTab!=0 );
if( !pTab->pSelect ){
sqlite3_value *pValue = 0;
u8 enc = ENC(sqlite3VdbeDb(v));
Column *pCol = &pTab->aCol[i];
VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));
assert( i<pTab->nCol );
sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc,
pCol->affinity, &pValue);
if( pValue ){
sqlite3VdbeAppendP4(v, pValue, P4_MEM);
}
}
#ifndef SQLITE_OMIT_FLOATING_POINT
if( pTab->aCol[i].affinity==SQLITE_AFF_REAL && !IsVirtual(pTab) ){
sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
}
#endif
}
/*
** Check to see if column iCol of index pIdx references any of the
** columns defined by aXRef and chngRowid. Return true if it does
** and false if not. This is an optimization. False-positives are a
** performance degradation, but false-negatives can result in a corrupt
** index and incorrect answers.
**
** aXRef[j] will be non-negative if column j of the original table is
** being updated. chngRowid will be true if the rowid of the table is
** being updated.
*/
static int indexColumnIsBeingUpdated(
Index *pIdx, /* The index to check */
int iCol, /* Which column of the index to check */
int *aXRef, /* aXRef[j]>=0 if column j is being updated */
int chngRowid /* true if the rowid is being updated */
){
i16 iIdxCol = pIdx->aiColumn[iCol];
assert( iIdxCol!=XN_ROWID ); /* Cannot index rowid */
if( iIdxCol>=0 ){
return aXRef[iIdxCol]>=0;
}
assert( iIdxCol==XN_EXPR );
assert( pIdx->aColExpr!=0 );
assert( pIdx->aColExpr->a[iCol].pExpr!=0 );
return sqlite3ExprReferencesUpdatedColumn(pIdx->aColExpr->a[iCol].pExpr,
aXRef,chngRowid);
}
/*
** Check to see if index pIdx is a partial index whose conditional
** expression might change values due to an UPDATE. Return true if
** the index is subject to change and false if the index is guaranteed
** to be unchanged. This is an optimization. False-positives are a
** performance degradation, but false-negatives can result in a corrupt
** index and incorrect answers.
**
** aXRef[j] will be non-negative if column j of the original table is
** being updated. chngRowid will be true if the rowid of the table is
** being updated.
*/
static int indexWhereClauseMightChange(
Index *pIdx, /* The index to check */
int *aXRef, /* aXRef[j]>=0 if column j is being updated */
int chngRowid /* true if the rowid is being updated */
){
if( pIdx->pPartIdxWhere==0 ) return 0;
return sqlite3ExprReferencesUpdatedColumn(pIdx->pPartIdxWhere,
aXRef, chngRowid);
}
/*
** Allocate and return a pointer to an expression of type TK_ROW with
** Expr.iColumn set to value (iCol+1). The resolver will modify the
** expression to be a TK_COLUMN reading column iCol of the first
** table in the source-list (pSrc->a[0]).
*/
static Expr *exprRowColumn(Parse *pParse, int iCol){
Expr *pRet = sqlite3PExpr(pParse, TK_ROW, 0, 0);
if( pRet ) pRet->iColumn = iCol+1;
return pRet;
}
/*
** Assuming both the pLimit and pOrderBy parameters are NULL, this function
** generates VM code to run the query:
**
** SELECT <other-columns>, pChanges FROM pTabList WHERE pWhere
**
** and write the results to the ephemeral table already opened as cursor
** iEph. None of pChanges, pTabList or pWhere are modified or consumed by
** this function, they must be deleted by the caller.
**
** Or, if pLimit and pOrderBy are not NULL, and pTab is not a view:
**
** SELECT <other-columns>, pChanges FROM pTabList
** WHERE pWhere
** GROUP BY <other-columns>
** ORDER BY pOrderBy LIMIT pLimit
**
** If pTab is a view, the GROUP BY clause is omitted.
**
** Exactly how results are written to table iEph, and exactly what
** the <other-columns> in the query above are is determined by the type
** of table pTabList->a[0].pTab.
**
** If the table is a WITHOUT ROWID table, then argument pPk must be its
** PRIMARY KEY. In this case <other-columns> are the primary key columns
** of the table, in order. The results of the query are written to ephemeral
** table iEph as index keys, using OP_IdxInsert.
**
** If the table is actually a view, then <other-columns> are all columns of
** the view. The results are written to the ephemeral table iEph as records
** with automatically assigned integer keys.
**
** If the table is a virtual or ordinary intkey table, then <other-columns>
** is its rowid. For a virtual table, the results are written to iEph as
** records with automatically assigned integer keys For intkey tables, the
** rowid value in <other-columns> is used as the integer key, and the
** remaining fields make up the table record.
*/
static void updateFromSelect(
Parse *pParse, /* Parse context */
int iEph, /* Cursor for open eph. table */
Index *pPk, /* PK if table 0 is WITHOUT ROWID */
ExprList *pChanges, /* List of expressions to return */
SrcList *pTabList, /* List of tables to select from */
Expr *pWhere, /* WHERE clause for query */
ExprList *pOrderBy, /* ORDER BY clause */
Expr *pLimit /* LIMIT clause */
){
int i;
SelectDest dest;
Select *pSelect = 0;
ExprList *pList = 0;
ExprList *pGrp = 0;
Expr *pLimit2 = 0;
ExprList *pOrderBy2 = 0;
sqlite3 *db = pParse->db;
Table *pTab = pTabList->a[0].pTab;
SrcList *pSrc;
Expr *pWhere2;
int eDest;
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( pOrderBy && pLimit==0 ) {
sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on UPDATE");
return;
}
pOrderBy2 = sqlite3ExprListDup(db, pOrderBy, 0);
pLimit2 = sqlite3ExprDup(db, pLimit, 0);
#else
UNUSED_PARAMETER(pOrderBy);
UNUSED_PARAMETER(pLimit);
#endif
pSrc = sqlite3SrcListDup(db, pTabList, 0);
pWhere2 = sqlite3ExprDup(db, pWhere, 0);
assert( pTabList->nSrc>1 );
if( pSrc ){
pSrc->a[0].iCursor = -1;
pSrc->a[0].pTab->nTabRef--;
pSrc->a[0].pTab = 0;
}
if( pPk ){
for(i=0; i<pPk->nKeyCol; i++){
Expr *pNew = exprRowColumn(pParse, pPk->aiColumn[i]);
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( pLimit ){
pGrp = sqlite3ExprListAppend(pParse, pGrp, sqlite3ExprDup(db, pNew, 0));
}
#endif
pList = sqlite3ExprListAppend(pParse, pList, pNew);
}
eDest = IsVirtual(pTab) ? SRT_Table : SRT_Upfrom;
}else if( pTab->pSelect ){
for(i=0; i<pTab->nCol; i++){
pList = sqlite3ExprListAppend(pParse, pList, exprRowColumn(pParse, i));
}
eDest = SRT_Table;
}else{
eDest = IsVirtual(pTab) ? SRT_Table : SRT_Upfrom;
pList = sqlite3ExprListAppend(pParse, 0, sqlite3PExpr(pParse,TK_ROW,0,0));
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( pLimit ){
pGrp = sqlite3ExprListAppend(pParse, 0, sqlite3PExpr(pParse,TK_ROW,0,0));
}
#endif
}
if( ALWAYS(pChanges) ){
for(i=0; i<pChanges->nExpr; i++){
pList = sqlite3ExprListAppend(pParse, pList,
sqlite3ExprDup(db, pChanges->a[i].pExpr, 0)
);
}
}
pSelect = sqlite3SelectNew(pParse, pList,
pSrc, pWhere2, pGrp, 0, pOrderBy2, SF_UpdateFrom|SF_IncludeHidden, pLimit2
);
sqlite3SelectDestInit(&dest, eDest, iEph);
dest.iSDParm2 = (pPk ? pPk->nKeyCol : -1);
sqlite3Select(pParse, pSelect, &dest);
sqlite3SelectDelete(db, pSelect);
}
/*
** Process an UPDATE statement.
**
** UPDATE OR IGNORE tbl SET a=b, c=d FROM tbl2... WHERE e<5 AND f NOT NULL;
** \_______/ \_/ \______/ \_____/ \________________/
** onError | pChanges | pWhere
** \_______________________/
** pTabList
*/
SQLITE_PRIVATE void sqlite3Update(
Parse *pParse, /* The parser context */
SrcList *pTabList, /* The table in which we should change things */
ExprList *pChanges, /* Things to be changed */
Expr *pWhere, /* The WHERE clause. May be null */
int onError, /* How to handle constraint errors */
ExprList *pOrderBy, /* ORDER BY clause. May be null */
Expr *pLimit, /* LIMIT clause. May be null */
Upsert *pUpsert /* ON CONFLICT clause, or null */
){
int i, j, k; /* Loop counters */
Table *pTab; /* The table to be updated */
int addrTop = 0; /* VDBE instruction address of the start of the loop */
WhereInfo *pWInfo = 0; /* Information about the WHERE clause */
Vdbe *v; /* The virtual database engine */
Index *pIdx; /* For looping over indices */
Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */
int nIdx; /* Number of indices that need updating */
int nAllIdx; /* Total number of indexes */
int iBaseCur; /* Base cursor number */
int iDataCur; /* Cursor for the canonical data btree */
int iIdxCur; /* Cursor for the first index */
sqlite3 *db; /* The database structure */
int *aRegIdx = 0; /* Registers for to each index and the main table */
int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the
** an expression for the i-th column of the table.
** aXRef[i]==-1 if the i-th column is not changed. */
u8 *aToOpen; /* 1 for tables and indices to be opened */
u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */
u8 chngRowid; /* Rowid changed in a normal table */
u8 chngKey; /* Either chngPk or chngRowid */
Expr *pRowidExpr = 0; /* Expression defining the new record number */
int iRowidExpr = -1; /* Index of "rowid=" (or IPK) assignment in pChanges */
AuthContext sContext; /* The authorization context */
NameContext sNC; /* The name-context to resolve expressions in */
int iDb; /* Database containing the table being updated */
int eOnePass; /* ONEPASS_XXX value from where.c */
int hasFK; /* True if foreign key processing is required */
int labelBreak; /* Jump here to break out of UPDATE loop */
int labelContinue; /* Jump here to continue next step of UPDATE loop */
int flags; /* Flags for sqlite3WhereBegin() */
#ifndef SQLITE_OMIT_TRIGGER
int isView; /* True when updating a view (INSTEAD OF trigger) */
Trigger *pTrigger; /* List of triggers on pTab, if required */
int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */
#endif
int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */
int iEph = 0; /* Ephemeral table holding all primary key values */
int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */
int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
int addrOpen = 0; /* Address of OP_OpenEphemeral */
int iPk = 0; /* First of nPk cells holding PRIMARY KEY value */
i16 nPk = 0; /* Number of components of the PRIMARY KEY */
int bReplace = 0; /* True if REPLACE conflict resolution might happen */
int bFinishSeek = 1; /* The OP_FinishSeek opcode is needed */
int nChangeFrom = 0; /* If there is a FROM, pChanges->nExpr, else 0 */
/* Register Allocations */
int regRowCount = 0; /* A count of rows changed */
int regOldRowid = 0; /* The old rowid */
int regNewRowid = 0; /* The new rowid */
int regNew = 0; /* Content of the NEW.* table in triggers */
int regOld = 0; /* Content of OLD.* table in triggers */
int regRowSet = 0; /* Rowset of rows to be updated */
int regKey = 0; /* composite PRIMARY KEY value */
memset(&sContext, 0, sizeof(sContext));
db = pParse->db;
if( pParse->nErr || db->mallocFailed ){
goto update_cleanup;
}
/* Locate the table which we want to update.
*/
pTab = sqlite3SrcListLookup(pParse, pTabList);
if( pTab==0 ) goto update_cleanup;
iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
/* Figure out if we have any triggers and if the table being
** updated is a view.
*/
#ifndef SQLITE_OMIT_TRIGGER
pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);
isView = pTab->pSelect!=0;
assert( pTrigger || tmask==0 );
#else
# define pTrigger 0
# define isView 0
# define tmask 0
#endif
#ifdef SQLITE_OMIT_VIEW
# undef isView
# define isView 0
#endif
/* If there was a FROM clause, set nChangeFrom to the number of expressions
** in the change-list. Otherwise, set it to 0. There cannot be a FROM
** clause if this function is being called to generate code for part of
** an UPSERT statement. */
nChangeFrom = (pTabList->nSrc>1) ? pChanges->nExpr : 0;
assert( nChangeFrom==0 || pUpsert==0 );
#ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
if( !isView && nChangeFrom==0 ){
pWhere = sqlite3LimitWhere(
pParse, pTabList, pWhere, pOrderBy, pLimit, "UPDATE"
);
pOrderBy = 0;
pLimit = 0;
}
#endif
if( sqlite3ViewGetColumnNames(pParse, pTab) ){
goto update_cleanup;
}
if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
goto update_cleanup;
}
/* Allocate a cursors for the main database table and for all indices.
** The index cursors might not be used, but if they are used they
** need to occur right after the database cursor. So go ahead and
** allocate enough space, just in case.
*/
iBaseCur = iDataCur = pParse->nTab++;
iIdxCur = iDataCur+1;
pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
testcase( pPk!=0 && pPk!=pTab->pIndex );
for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
if( pPk==pIdx ){
iDataCur = pParse->nTab;
}
pParse->nTab++;
}
if( pUpsert ){
/* On an UPSERT, reuse the same cursors already opened by INSERT */
iDataCur = pUpsert->iDataCur;
iIdxCur = pUpsert->iIdxCur;
pParse->nTab = iBaseCur;
}
pTabList->a[0].iCursor = iDataCur;
/* Allocate space for aXRef[], aRegIdx[], and aToOpen[].
** Initialize aXRef[] and aToOpen[] to their default values.
*/
aXRef = sqlite3DbMallocRawNN(db, sizeof(int) * (pTab->nCol+nIdx+1) + nIdx+2 );
if( aXRef==0 ) goto update_cleanup;
aRegIdx = aXRef+pTab->nCol;
aToOpen = (u8*)(aRegIdx+nIdx+1);
memset(aToOpen, 1, nIdx+1);
aToOpen[nIdx+1] = 0;
for(i=0; i<pTab->nCol; i++) aXRef[i] = -1;
/* Initialize the name-context */
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
sNC.uNC.pUpsert = pUpsert;
sNC.ncFlags = NC_UUpsert;
/* Begin generating code. */
v = sqlite3GetVdbe(pParse);
if( v==0 ) goto update_cleanup;
/* Resolve the column names in all the expressions of the
** of the UPDATE statement. Also find the column index
** for each column to be updated in the pChanges array. For each
** column to be updated, make sure we have authorization to change
** that column.
*/
chngRowid = chngPk = 0;
for(i=0; i<pChanges->nExpr; i++){
/* If this is an UPDATE with a FROM clause, do not resolve expressions
** here. The call to sqlite3Select() below will do that. */
if( nChangeFrom==0 && sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){
goto update_cleanup;
}
for(j=0; j<pTab->nCol; j++){
if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zEName)==0 ){
if( j==pTab->iPKey ){
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
iRowidExpr = i;
}else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){
chngPk = 1;
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
else if( pTab->aCol[j].colFlags & COLFLAG_GENERATED ){
testcase( pTab->aCol[j].colFlags & COLFLAG_VIRTUAL );
testcase( pTab->aCol[j].colFlags & COLFLAG_STORED );
sqlite3ErrorMsg(pParse,
"cannot UPDATE generated column \"%s\"",
pTab->aCol[j].zName);
goto update_cleanup;
}
#endif
aXRef[j] = i;
break;
}
}
if( j>=pTab->nCol ){
if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zEName) ){
j = -1;
chngRowid = 1;
pRowidExpr = pChanges->a[i].pExpr;
iRowidExpr = i;
}else{
sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zEName);
pParse->checkSchema = 1;
goto update_cleanup;
}
}
#ifndef SQLITE_OMIT_AUTHORIZATION
{
int rc;
rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName,
j<0 ? "ROWID" : pTab->aCol[j].zName,
db->aDb[iDb].zDbSName);
if( rc==SQLITE_DENY ){
goto update_cleanup;
}else if( rc==SQLITE_IGNORE ){
aXRef[j] = -1;
}
}
#endif
}
assert( (chngRowid & chngPk)==0 );
assert( chngRowid==0 || chngRowid==1 );
assert( chngPk==0 || chngPk==1 );
chngKey = chngRowid + chngPk;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* Mark generated columns as changing if their generator expressions
** reference any changing column. The actual aXRef[] value for
** generated expressions is not used, other than to check to see that it
** is non-negative, so the value of aXRef[] for generated columns can be
** set to any non-negative number. We use 99999 so that the value is
** obvious when looking at aXRef[] in a symbolic debugger.
*/
if( pTab->tabFlags & TF_HasGenerated ){
int bProgress;
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
do{
bProgress = 0;
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ) continue;
if( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)==0 ) continue;
if( sqlite3ExprReferencesUpdatedColumn(pTab->aCol[i].pDflt,
aXRef, chngRowid) ){
aXRef[i] = 99999;
bProgress = 1;
}
}
}while( bProgress );
}
#endif
/* The SET expressions are not actually used inside the WHERE loop.
** So reset the colUsed mask. Unless this is a virtual table. In that
** case, set all bits of the colUsed mask (to ensure that the virtual
** table implementation makes all columns available).
*/
pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0;
hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);
/* There is one entry in the aRegIdx[] array for each index on the table
** being updated. Fill in aRegIdx[] with a register number that will hold
** the key for accessing each index.
*/
if( onError==OE_Replace ) bReplace = 1;
for(nAllIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nAllIdx++){
int reg;
if( chngKey || hasFK>1 || pIdx==pPk
|| indexWhereClauseMightChange(pIdx,aXRef,chngRowid)
){
reg = ++pParse->nMem;
pParse->nMem += pIdx->nColumn;
}else{
reg = 0;
for(i=0; i<pIdx->nKeyCol; i++){
if( indexColumnIsBeingUpdated(pIdx, i, aXRef, chngRowid) ){
reg = ++pParse->nMem;
pParse->nMem += pIdx->nColumn;
if( onError==OE_Default && pIdx->onError==OE_Replace ){
bReplace = 1;
}
break;
}
}
}
if( reg==0 ) aToOpen[nAllIdx+1] = 0;
aRegIdx[nAllIdx] = reg;
}
aRegIdx[nAllIdx] = ++pParse->nMem; /* Register storing the table record */
if( bReplace ){
/* If REPLACE conflict resolution might be invoked, open cursors on all
** indexes in case they are needed to delete records. */
memset(aToOpen, 1, nIdx+1);
}
if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
sqlite3BeginWriteOperation(pParse, pTrigger || hasFK, iDb);
/* Allocate required registers. */
if( !IsVirtual(pTab) ){
/* For now, regRowSet and aRegIdx[nAllIdx] share the same register.
** If regRowSet turns out to be needed, then aRegIdx[nAllIdx] will be
** reallocated. aRegIdx[nAllIdx] is the register in which the main
** table record is written. regRowSet holds the RowSet for the
** two-pass update algorithm. */
assert( aRegIdx[nAllIdx]==pParse->nMem );
regRowSet = aRegIdx[nAllIdx];
regOldRowid = regNewRowid = ++pParse->nMem;
if( chngPk || pTrigger || hasFK ){
regOld = pParse->nMem + 1;
pParse->nMem += pTab->nCol;
}
if( chngKey || pTrigger || hasFK ){
regNewRowid = ++pParse->nMem;
}
regNew = pParse->nMem + 1;
pParse->nMem += pTab->nCol;
}
/* Start the view context. */
if( isView ){
sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
}
/* If we are trying to update a view, realize that view into
** an ephemeral table.
*/
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
if( nChangeFrom==0 && isView ){
sqlite3MaterializeView(pParse, pTab,
pWhere, pOrderBy, pLimit, iDataCur
);
pOrderBy = 0;
pLimit = 0;
}
#endif
/* Resolve the column names in all the expressions in the
** WHERE clause.
*/
if( nChangeFrom==0 && sqlite3ResolveExprNames(&sNC, pWhere) ){
goto update_cleanup;
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Virtual tables must be handled separately */
if( IsVirtual(pTab) ){
updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
pWhere, onError);
goto update_cleanup;
}
#endif
/* Jump to labelBreak to abandon further processing of this UPDATE */
labelContinue = labelBreak = sqlite3VdbeMakeLabel(pParse);
/* Not an UPSERT. Normal processing. Begin by
** initialize the count of updated rows */
if( (db->flags&SQLITE_CountRows)!=0
&& !pParse->pTriggerTab
&& !pParse->nested
&& pUpsert==0
){
regRowCount = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
}
if( nChangeFrom==0 && HasRowid(pTab) ){
sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
iEph = pParse->nTab++;
addrOpen = sqlite3VdbeAddOp3(v, OP_OpenEphemeral, iEph, 0, regRowSet);
}else{
assert( pPk!=0 || HasRowid(pTab) );
nPk = pPk ? pPk->nKeyCol : 0;
iPk = pParse->nMem+1;
pParse->nMem += nPk;
pParse->nMem += nChangeFrom;
regKey = ++pParse->nMem;
if( pUpsert==0 ){
int nEphCol = nPk + nChangeFrom + (isView ? pTab->nCol : 0);
iEph = pParse->nTab++;
if( pPk ) sqlite3VdbeAddOp3(v, OP_Null, 0, iPk, iPk+nPk-1);
addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nEphCol);
if( pPk ){
KeyInfo *pKeyInfo = sqlite3KeyInfoOfIndex(pParse, pPk);
if( pKeyInfo ){
pKeyInfo->nAllField = nEphCol;
sqlite3VdbeAppendP4(v, pKeyInfo, P4_KEYINFO);
}
}
if( nChangeFrom ){
updateFromSelect(
pParse, iEph, pPk, pChanges, pTabList, pWhere, pOrderBy, pLimit
);
#ifndef SQLITE_OMIT_SUBQUERY
if( isView ) iDataCur = iEph;
#endif
}
}
}
if( nChangeFrom ){
sqlite3MultiWrite(pParse);
eOnePass = ONEPASS_OFF;
nKey = nPk;
regKey = iPk;
}else{
if( pUpsert ){
/* If this is an UPSERT, then all cursors have already been opened by
** the outer INSERT and the data cursor should be pointing at the row
** that is to be updated. So bypass the code that searches for the
** row(s) to be updated.
*/
pWInfo = 0;
eOnePass = ONEPASS_SINGLE;
sqlite3ExprIfFalse(pParse, pWhere, labelBreak, SQLITE_JUMPIFNULL);
bFinishSeek = 0;
}else{
/* Begin the database scan.
**
** Do not consider a single-pass strategy for a multi-row update if
** there are any triggers or foreign keys to process, or rows may
** be deleted as a result of REPLACE conflict handling. Any of these
** things might disturb a cursor being used to scan through the table
** or index, causing a single-pass approach to malfunction. */
flags = WHERE_ONEPASS_DESIRED;
if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){
flags |= WHERE_ONEPASS_MULTIROW;
}
pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, flags,iIdxCur);
if( pWInfo==0 ) goto update_cleanup;
/* A one-pass strategy that might update more than one row may not
** be used if any column of the index used for the scan is being
** updated. Otherwise, if there is an index on "b", statements like
** the following could create an infinite loop:
**
** UPDATE t1 SET b=b+1 WHERE b>?
**
** Fall back to ONEPASS_OFF if where.c has selected a ONEPASS_MULTI
** strategy that uses an index for which one or more columns are being
** updated. */
eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
bFinishSeek = sqlite3WhereUsesDeferredSeek(pWInfo);
if( eOnePass!=ONEPASS_SINGLE ){
sqlite3MultiWrite(pParse);
if( eOnePass==ONEPASS_MULTI ){
int iCur = aiCurOnePass[1];
if( iCur>=0 && iCur!=iDataCur && aToOpen[iCur-iBaseCur] ){
eOnePass = ONEPASS_OFF;
}
assert( iCur!=iDataCur || !HasRowid(pTab) );
}
}
}
if( HasRowid(pTab) ){
/* Read the rowid of the current row of the WHERE scan. In ONEPASS_OFF
** mode, write the rowid into the FIFO. In either of the one-pass modes,
** leave it in register regOldRowid. */
sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
if( eOnePass==ONEPASS_OFF ){
aRegIdx[nAllIdx] = ++pParse->nMem;
sqlite3VdbeAddOp3(v, OP_Insert, iEph, regRowSet, regOldRowid);
}else{
if( ALWAYS(addrOpen) ) sqlite3VdbeChangeToNoop(v, addrOpen);
}
}else{
/* Read the PK of the current row into an array of registers. In
** ONEPASS_OFF mode, serialize the array into a record and store it in
** the ephemeral table. Or, in ONEPASS_SINGLE or MULTI mode, change
** the OP_OpenEphemeral instruction to a Noop (the ephemeral table
** is not required) and leave the PK fields in the array of registers. */
for(i=0; i<nPk; i++){
assert( pPk->aiColumn[i]>=0 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur,
pPk->aiColumn[i], iPk+i);
}
if( eOnePass ){
if( addrOpen ) sqlite3VdbeChangeToNoop(v, addrOpen);
nKey = nPk;
regKey = iPk;
}else{
sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey,
sqlite3IndexAffinityStr(db, pPk), nPk);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEph, regKey, iPk, nPk);
}
}
}
if( pUpsert==0 ){
if( nChangeFrom==0 && eOnePass!=ONEPASS_MULTI ){
sqlite3WhereEnd(pWInfo);
}
if( !isView ){
int addrOnce = 0;
/* Open every index that needs updating. */
if( eOnePass!=ONEPASS_OFF ){
if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0;
if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0;
}
if( eOnePass==ONEPASS_MULTI && (nIdx-(aiCurOnePass[1]>=0))>0 ){
addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
}
sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur,
aToOpen, 0, 0);
if( addrOnce ){
sqlite3VdbeJumpHereOrPopInst(v, addrOnce);
}
}
/* Top of the update loop */
if( eOnePass!=ONEPASS_OFF ){
if( !isView && aiCurOnePass[0]!=iDataCur && aiCurOnePass[1]!=iDataCur ){
assert( pPk );
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey,nKey);
VdbeCoverage(v);
}
if( eOnePass!=ONEPASS_SINGLE ){
labelContinue = sqlite3VdbeMakeLabel(pParse);
}
sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak);
VdbeCoverageIf(v, pPk==0);
VdbeCoverageIf(v, pPk!=0);
}else if( pPk || nChangeFrom ){
labelContinue = sqlite3VdbeMakeLabel(pParse);
sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
addrTop = sqlite3VdbeCurrentAddr(v);
if( nChangeFrom ){
if( !isView ){
if( pPk ){
for(i=0; i<nPk; i++){
sqlite3VdbeAddOp3(v, OP_Column, iEph, i, iPk+i);
}
sqlite3VdbeAddOp4Int(
v, OP_NotFound, iDataCur, labelContinue, iPk, nPk
); VdbeCoverage(v);
}else{
sqlite3VdbeAddOp2(v, OP_Rowid, iEph, regOldRowid);
sqlite3VdbeAddOp3(
v, OP_NotExists, iDataCur, labelContinue, regOldRowid
); VdbeCoverage(v);
}
}
}else{
sqlite3VdbeAddOp2(v, OP_RowData, iEph, regKey);
sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey,0);
VdbeCoverage(v);
}
}else{
sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
labelContinue = sqlite3VdbeMakeLabel(pParse);
addrTop = sqlite3VdbeAddOp2(v, OP_Rowid, iEph, regOldRowid);
VdbeCoverage(v);
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
VdbeCoverage(v);
}
}
/* If the rowid value will change, set register regNewRowid to
** contain the new value. If the rowid is not being modified,
** then regNewRowid is the same register as regOldRowid, which is
** already populated. */
assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );
if( chngRowid ){
assert( iRowidExpr>=0 );
if( nChangeFrom==0 ){
sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
}else{
sqlite3VdbeAddOp3(v, OP_Column, iEph, iRowidExpr, regNewRowid);
}
sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v);
}
/* Compute the old pre-UPDATE content of the row being changed, if that
** information is needed */
if( chngPk || hasFK || pTrigger ){
u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0);
oldmask |= sqlite3TriggerColmask(pParse,
pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError
);
for(i=0; i<pTab->nCol; i++){
u32 colFlags = pTab->aCol[i].colFlags;
k = sqlite3TableColumnToStorage(pTab, i) + regOld;
if( oldmask==0xffffffff
|| (i<32 && (oldmask & MASKBIT32(i))!=0)
|| (colFlags & COLFLAG_PRIMKEY)!=0
){
testcase( oldmask!=0xffffffff && i==31 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, k);
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, k);
}
}
if( chngRowid==0 && pPk==0 ){
sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid);
}
}
/* Populate the array of registers beginning at regNew with the new
** row data. This array is used to check constants, create the new
** table and index records, and as the values for any new.* references
** made by triggers.
**
** If there are one or more BEFORE triggers, then do not populate the
** registers associated with columns that are (a) not modified by
** this UPDATE statement and (b) not accessed by new.* references. The
** values for registers not modified by the UPDATE must be reloaded from
** the database after the BEFORE triggers are fired anyway (as the trigger
** may have modified them). So not loading those that are not going to
** be used eliminates some redundant opcodes.
*/
newmask = sqlite3TriggerColmask(
pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError
);
for(i=0, k=regNew; i<pTab->nCol; i++, k++){
if( i==pTab->iPKey ){
sqlite3VdbeAddOp2(v, OP_Null, 0, k);
}else if( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)!=0 ){
if( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL ) k--;
}else{
j = aXRef[i];
if( j>=0 ){
if( nChangeFrom ){
int nOff = (isView ? pTab->nCol : nPk);
assert( eOnePass==ONEPASS_OFF );
sqlite3VdbeAddOp3(v, OP_Column, iEph, nOff+j, k);
}else{
sqlite3ExprCode(pParse, pChanges->a[j].pExpr, k);
}
}else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){
/* This branch loads the value of a column that will not be changed
** into a register. This is done if there are no BEFORE triggers, or
** if there are one or more BEFORE triggers that use this value via
** a new.* reference in a trigger program.
*/
testcase( i==31 );
testcase( i==32 );
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, k);
bFinishSeek = 0;
}else{
sqlite3VdbeAddOp2(v, OP_Null, 0, k);
}
}
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( pTab->tabFlags & TF_HasGenerated ){
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
sqlite3ComputeGeneratedColumns(pParse, regNew, pTab);
}
#endif
/* Fire any BEFORE UPDATE triggers. This happens before constraints are
** verified. One could argue that this is wrong.
*/
if( tmask&TRIGGER_BEFORE ){
sqlite3TableAffinity(v, pTab, regNew);
sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges,
TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue);
if( !isView ){
/* The row-trigger may have deleted the row being updated. In this
** case, jump to the next row. No updates or AFTER triggers are
** required. This behavior - what happens when the row being updated
** is deleted or renamed by a BEFORE trigger - is left undefined in the
** documentation.
*/
if( pPk ){
sqlite3VdbeAddOp4Int(v, OP_NotFound,iDataCur,labelContinue,regKey,nKey);
VdbeCoverage(v);
}else{
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue,regOldRowid);
VdbeCoverage(v);
}
/* After-BEFORE-trigger-reload-loop:
** If it did not delete it, the BEFORE trigger may still have modified
** some of the columns of the row being updated. Load the values for
** all columns not modified by the update statement into their registers
** in case this has happened. Only unmodified columns are reloaded.
** The values computed for modified columns use the values before the
** BEFORE trigger runs. See test case trigger1-18.0 (added 2018-04-26)
** for an example.
*/
for(i=0, k=regNew; i<pTab->nCol; i++, k++){
if( pTab->aCol[i].colFlags & COLFLAG_GENERATED ){
if( pTab->aCol[i].colFlags & COLFLAG_VIRTUAL ) k--;
}else if( aXRef[i]<0 && i!=pTab->iPKey ){
sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, k);
}
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
if( pTab->tabFlags & TF_HasGenerated ){
testcase( pTab->tabFlags & TF_HasVirtual );
testcase( pTab->tabFlags & TF_HasStored );
sqlite3ComputeGeneratedColumns(pParse, regNew, pTab);
}
#endif
}
}
if( !isView ){
/* Do constraint checks. */
assert( regOldRowid>0 );
sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace,
aXRef, 0);
/* If REPLACE conflict handling may have been used, or if the PK of the
** row is changing, then the GenerateConstraintChecks() above may have
** moved cursor iDataCur. Reseek it. */
if( bReplace || chngKey ){
if( pPk ){
sqlite3VdbeAddOp4Int(v, OP_NotFound,iDataCur,labelContinue,regKey,nKey);
}else{
sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue,regOldRowid);
}
VdbeCoverageNeverTaken(v);
}
/* Do FK constraint checks. */
if( hasFK ){
sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
}
/* Delete the index entries associated with the current record. */
sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1);
/* We must run the OP_FinishSeek opcode to resolve a prior
** OP_DeferredSeek if there is any possibility that there have been
** no OP_Column opcodes since the OP_DeferredSeek was issued. But
** we want to avoid the OP_FinishSeek if possible, as running it
** costs CPU cycles. */
if( bFinishSeek ){
sqlite3VdbeAddOp1(v, OP_FinishSeek, iDataCur);
}
/* If changing the rowid value, or if there are foreign key constraints
** to process, delete the old record. Otherwise, add a noop OP_Delete
** to invoke the pre-update hook.
**
** That (regNew==regnewRowid+1) is true is also important for the
** pre-update hook. If the caller invokes preupdate_new(), the returned
** value is copied from memory cell (regNewRowid+1+iCol), where iCol
** is the column index supplied by the user.
*/
assert( regNew==regNewRowid+1 );
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
sqlite3VdbeAddOp3(v, OP_Delete, iDataCur,
OPFLAG_ISUPDATE | ((hasFK>1 || chngKey) ? 0 : OPFLAG_ISNOOP),
regNewRowid
);
if( eOnePass==ONEPASS_MULTI ){
assert( hasFK==0 && chngKey==0 );
sqlite3VdbeChangeP5(v, OPFLAG_SAVEPOSITION);
}
if( !pParse->nested ){
sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
}
#else
if( hasFK>1 || chngKey ){
sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
}
#endif
if( hasFK ){
sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey);
}
/* Insert the new index entries and the new record. */
sqlite3CompleteInsertion(
pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx,
OPFLAG_ISUPDATE | (eOnePass==ONEPASS_MULTI ? OPFLAG_SAVEPOSITION : 0),
0, 0
);
/* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
** handle rows (possibly in other tables) that refer via a foreign key
** to the row just updated. */
if( hasFK ){
sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey);
}
}
/* Increment the row counter
*/
if( regRowCount ){
sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
}
sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges,
TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue);
/* Repeat the above with the next record to be updated, until
** all record selected by the WHERE clause have been updated.
*/
if( eOnePass==ONEPASS_SINGLE ){
/* Nothing to do at end-of-loop for a single-pass */
}else if( eOnePass==ONEPASS_MULTI ){
sqlite3VdbeResolveLabel(v, labelContinue);
sqlite3WhereEnd(pWInfo);
}else{
sqlite3VdbeResolveLabel(v, labelContinue);
sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);
}
sqlite3VdbeResolveLabel(v, labelBreak);
/* Update the sqlite_sequence table by storing the content of the
** maximum rowid counter values recorded while inserting into
** autoincrement tables.
*/
if( pParse->nested==0 && pParse->pTriggerTab==0 && pUpsert==0 ){
sqlite3AutoincrementEnd(pParse);
}
/*
** Return the number of rows that were changed, if we are tracking
** that information.
*/
if( regRowCount ){
sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
sqlite3VdbeSetNumCols(v, 1);
sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC);
}
update_cleanup:
sqlite3AuthContextPop(&sContext);
sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */
sqlite3SrcListDelete(db, pTabList);
sqlite3ExprListDelete(db, pChanges);
sqlite3ExprDelete(db, pWhere);
#if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
sqlite3ExprListDelete(db, pOrderBy);
sqlite3ExprDelete(db, pLimit);
#endif
return;
}
/* Make sure "isView" and other macros defined above are undefined. Otherwise
** they may interfere with compilation of other functions in this file
** (or in another file, if this file becomes part of the amalgamation). */
#ifdef isView
#undef isView
#endif
#ifdef pTrigger
#undef pTrigger
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Generate code for an UPDATE of a virtual table.
**
** There are two possible strategies - the default and the special
** "onepass" strategy. Onepass is only used if the virtual table
** implementation indicates that pWhere may match at most one row.
**
** The default strategy is to create an ephemeral table that contains
** for each row to be changed:
**
** (A) The original rowid of that row.
** (B) The revised rowid for the row.
** (C) The content of every column in the row.
**
** Then loop through the contents of this ephemeral table executing a
** VUpdate for each row. When finished, drop the ephemeral table.
**
** The "onepass" strategy does not use an ephemeral table. Instead, it
** stores the same values (A, B and C above) in a register array and
** makes a single invocation of VUpdate.
*/
static void updateVirtualTable(
Parse *pParse, /* The parsing context */
SrcList *pSrc, /* The virtual table to be modified */
Table *pTab, /* The virtual table */
ExprList *pChanges, /* The columns to change in the UPDATE statement */
Expr *pRowid, /* Expression used to recompute the rowid */
int *aXRef, /* Mapping from columns of pTab to entries in pChanges */
Expr *pWhere, /* WHERE clause of the UPDATE statement */
int onError /* ON CONFLICT strategy */
){
Vdbe *v = pParse->pVdbe; /* Virtual machine under construction */
int ephemTab; /* Table holding the result of the SELECT */
int i; /* Loop counter */
sqlite3 *db = pParse->db; /* Database connection */
const char *pVTab = (const char*)sqlite3GetVTable(db, pTab);
WhereInfo *pWInfo = 0;
int nArg = 2 + pTab->nCol; /* Number of arguments to VUpdate */
int regArg; /* First register in VUpdate arg array */
int regRec; /* Register in which to assemble record */
int regRowid; /* Register for ephem table rowid */
int iCsr = pSrc->a[0].iCursor; /* Cursor used for virtual table scan */
int aDummy[2]; /* Unused arg for sqlite3WhereOkOnePass() */
int eOnePass; /* True to use onepass strategy */
int addr; /* Address of OP_OpenEphemeral */
/* Allocate nArg registers in which to gather the arguments for VUpdate. Then
** create and open the ephemeral table in which the records created from
** these arguments will be temporarily stored. */
assert( v );
ephemTab = pParse->nTab++;
addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg);
regArg = pParse->nMem + 1;
pParse->nMem += nArg;
if( pSrc->nSrc>1 ){
Index *pPk = 0;
Expr *pRow;
ExprList *pList;
if( HasRowid(pTab) ){
if( pRowid ){
pRow = sqlite3ExprDup(db, pRowid, 0);
}else{
pRow = sqlite3PExpr(pParse, TK_ROW, 0, 0);
}
}else{
i16 iPk; /* PRIMARY KEY column */
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
assert( pPk->nKeyCol==1 );
iPk = pPk->aiColumn[0];
if( aXRef[iPk]>=0 ){
pRow = sqlite3ExprDup(db, pChanges->a[aXRef[iPk]].pExpr, 0);
}else{
pRow = exprRowColumn(pParse, iPk);
}
}
pList = sqlite3ExprListAppend(pParse, 0, pRow);
for(i=0; i<pTab->nCol; i++){
if( aXRef[i]>=0 ){
pList = sqlite3ExprListAppend(pParse, pList,
sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0)
);
}else{
pList = sqlite3ExprListAppend(pParse, pList, exprRowColumn(pParse, i));
}
}
updateFromSelect(pParse, ephemTab, pPk, pList, pSrc, pWhere, 0, 0);
sqlite3ExprListDelete(db, pList);
eOnePass = ONEPASS_OFF;
}else{
regRec = ++pParse->nMem;
regRowid = ++pParse->nMem;
/* Start scanning the virtual table */
pWInfo = sqlite3WhereBegin(pParse, pSrc,pWhere,0,0,WHERE_ONEPASS_DESIRED,0);
if( pWInfo==0 ) return;
/* Populate the argument registers. */
for(i=0; i<pTab->nCol; i++){
assert( (pTab->aCol[i].colFlags & COLFLAG_GENERATED)==0 );
if( aXRef[i]>=0 ){
sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
}else{
sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG);/* For sqlite3_vtab_nochange() */
}
}
if( HasRowid(pTab) ){
sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg);
if( pRowid ){
sqlite3ExprCode(pParse, pRowid, regArg+1);
}else{
sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1);
}
}else{
Index *pPk; /* PRIMARY KEY index */
i16 iPk; /* PRIMARY KEY column */
pPk = sqlite3PrimaryKeyIndex(pTab);
assert( pPk!=0 );
assert( pPk->nKeyCol==1 );
iPk = pPk->aiColumn[0];
sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, iPk, regArg);
sqlite3VdbeAddOp2(v, OP_SCopy, regArg+2+iPk, regArg+1);
}
eOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy);
/* There is no ONEPASS_MULTI on virtual tables */
assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );
if( eOnePass ){
/* If using the onepass strategy, no-op out the OP_OpenEphemeral coded
** above. */
sqlite3VdbeChangeToNoop(v, addr);
sqlite3VdbeAddOp1(v, OP_Close, iCsr);
}else{
/* Create a record from the argument register contents and insert it into
** the ephemeral table. */
sqlite3MultiWrite(pParse);
sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec);
#if defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_NULL_TRIM)
/* Signal an assert() within OP_MakeRecord that it is allowed to
** accept no-change records with serial_type 10 */
sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG_MAGIC);
#endif
sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid);
sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid);
}
}
if( eOnePass==ONEPASS_OFF ){
/* End the virtual table scan */
if( pSrc->nSrc==1 ){
sqlite3WhereEnd(pWInfo);
}
/* Begin scannning through the ephemeral table. */
addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v);
/* Extract arguments from the current row of the ephemeral table and
** invoke the VUpdate method. */
for(i=0; i<nArg; i++){
sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i, regArg+i);
}
}
sqlite3VtabMakeWritable(pParse, pTab);
sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB);
sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
sqlite3MayAbort(pParse);
/* End of the ephemeral table scan. Or, if using the onepass strategy,
** jump to here if the scan visited zero rows. */
if( eOnePass==ONEPASS_OFF ){
sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v);
sqlite3VdbeJumpHere(v, addr);
sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);
}else{
sqlite3WhereEnd(pWInfo);
}
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
/************** End of update.c **********************************************/
/************** Begin file upsert.c ******************************************/
/*
** 2018-04-12
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code to implement various aspects of UPSERT
** processing and handling of the Upsert object.
*/
/* #include "sqliteInt.h" */
#ifndef SQLITE_OMIT_UPSERT
/*
** Free a list of Upsert objects
*/
SQLITE_PRIVATE void sqlite3UpsertDelete(sqlite3 *db, Upsert *p){
if( p ){
sqlite3ExprListDelete(db, p->pUpsertTarget);
sqlite3ExprDelete(db, p->pUpsertTargetWhere);
sqlite3ExprListDelete(db, p->pUpsertSet);
sqlite3ExprDelete(db, p->pUpsertWhere);
sqlite3DbFree(db, p);
}
}
/*
** Duplicate an Upsert object.
*/
SQLITE_PRIVATE Upsert *sqlite3UpsertDup(sqlite3 *db, Upsert *p){
if( p==0 ) return 0;
return sqlite3UpsertNew(db,
sqlite3ExprListDup(db, p->pUpsertTarget, 0),
sqlite3ExprDup(db, p->pUpsertTargetWhere, 0),
sqlite3ExprListDup(db, p->pUpsertSet, 0),
sqlite3ExprDup(db, p->pUpsertWhere, 0)
);
}
/*
** Create a new Upsert object.
*/
SQLITE_PRIVATE Upsert *sqlite3UpsertNew(
sqlite3 *db, /* Determines which memory allocator to use */
ExprList *pTarget, /* Target argument to ON CONFLICT, or NULL */
Expr *pTargetWhere, /* Optional WHERE clause on the target */
ExprList *pSet, /* UPDATE columns, or NULL for a DO NOTHING */
Expr *pWhere /* WHERE clause for the ON CONFLICT UPDATE */
){
Upsert *pNew;
pNew = sqlite3DbMallocRaw(db, sizeof(Upsert));
if( pNew==0 ){
sqlite3ExprListDelete(db, pTarget);
sqlite3ExprDelete(db, pTargetWhere);
sqlite3ExprListDelete(db, pSet);
sqlite3ExprDelete(db, pWhere);
return 0;
}else{
pNew->pUpsertTarget = pTarget;
pNew->pUpsertTargetWhere = pTargetWhere;
pNew->pUpsertSet = pSet;
pNew->pUpsertWhere = pWhere;
pNew->pUpsertIdx = 0;
}
return pNew;
}
/*
** Analyze the ON CONFLICT clause described by pUpsert. Resolve all
** symbols in the conflict-target.
**
** Return SQLITE_OK if everything works, or an error code is something
** is wrong.
*/
SQLITE_PRIVATE int sqlite3UpsertAnalyzeTarget(
Parse *pParse, /* The parsing context */
SrcList *pTabList, /* Table into which we are inserting */
Upsert *pUpsert /* The ON CONFLICT clauses */
){
Table *pTab; /* That table into which we are inserting */
int rc; /* Result code */
int iCursor; /* Cursor used by pTab */
Index *pIdx; /* One of the indexes of pTab */
ExprList *pTarget; /* The conflict-target clause */
Expr *pTerm; /* One term of the conflict-target clause */
NameContext sNC; /* Context for resolving symbolic names */
Expr sCol[2]; /* Index column converted into an Expr */
assert( pTabList->nSrc==1 );
assert( pTabList->a[0].pTab!=0 );
assert( pUpsert!=0 );
assert( pUpsert->pUpsertTarget!=0 );
/* Resolve all symbolic names in the conflict-target clause, which
** includes both the list of columns and the optional partial-index
** WHERE clause.
*/
memset(&sNC, 0, sizeof(sNC));
sNC.pParse = pParse;
sNC.pSrcList = pTabList;
rc = sqlite3ResolveExprListNames(&sNC, pUpsert->pUpsertTarget);
if( rc ) return rc;
rc = sqlite3ResolveExprNames(&sNC, pUpsert->pUpsertTargetWhere);
if( rc ) return rc;
/* Check to see if the conflict target matches the rowid. */
pTab = pTabList->a[0].pTab;
pTarget = pUpsert->pUpsertTarget;
iCursor = pTabList->a[0].iCursor;
if( HasRowid(pTab)
&& pTarget->nExpr==1
&& (pTerm = pTarget->a[0].pExpr)->op==TK_COLUMN
&& pTerm->iColumn==XN_ROWID
){
/* The conflict-target is the rowid of the primary table */
assert( pUpsert->pUpsertIdx==0 );
return SQLITE_OK;
}
/* Initialize sCol[0..1] to be an expression parse tree for a
** single column of an index. The sCol[0] node will be the TK_COLLATE
** operator and sCol[1] will be the TK_COLUMN operator. Code below
** will populate the specific collation and column number values
** prior to comparing against the conflict-target expression.
*/
memset(sCol, 0, sizeof(sCol));
sCol[0].op = TK_COLLATE;
sCol[0].pLeft = &sCol[1];
sCol[1].op = TK_COLUMN;
sCol[1].iTable = pTabList->a[0].iCursor;
/* Check for matches against other indexes */
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
int ii, jj, nn;
if( !IsUniqueIndex(pIdx) ) continue;
if( pTarget->nExpr!=pIdx->nKeyCol ) continue;
if( pIdx->pPartIdxWhere ){
if( pUpsert->pUpsertTargetWhere==0 ) continue;
if( sqlite3ExprCompare(pParse, pUpsert->pUpsertTargetWhere,
pIdx->pPartIdxWhere, iCursor)!=0 ){
continue;
}
}
nn = pIdx->nKeyCol;
for(ii=0; ii<nn; ii++){
Expr *pExpr;
sCol[0].u.zToken = (char*)pIdx->azColl[ii];
if( pIdx->aiColumn[ii]==XN_EXPR ){
assert( pIdx->aColExpr!=0 );
assert( pIdx->aColExpr->nExpr>ii );
pExpr = pIdx->aColExpr->a[ii].pExpr;
if( pExpr->op!=TK_COLLATE ){
sCol[0].pLeft = pExpr;
pExpr = &sCol[0];
}
}else{
sCol[0].pLeft = &sCol[1];
sCol[1].iColumn = pIdx->aiColumn[ii];
pExpr = &sCol[0];
}
for(jj=0; jj<nn; jj++){
if( sqlite3ExprCompare(pParse, pTarget->a[jj].pExpr, pExpr,iCursor)<2 ){
break; /* Column ii of the index matches column jj of target */
}
}
if( jj>=nn ){
/* The target contains no match for column jj of the index */
break;
}
}
if( ii<nn ){
/* Column ii of the index did not match any term of the conflict target.
** Continue the search with the next index. */
continue;
}
pUpsert->pUpsertIdx = pIdx;
return SQLITE_OK;
}
sqlite3ErrorMsg(pParse, "ON CONFLICT clause does not match any "
"PRIMARY KEY or UNIQUE constraint");
return SQLITE_ERROR;
}
/*
** Generate bytecode that does an UPDATE as part of an upsert.
**
** If pIdx is NULL, then the UNIQUE constraint that failed was the IPK.
** In this case parameter iCur is a cursor open on the table b-tree that
** currently points to the conflicting table row. Otherwise, if pIdx
** is not NULL, then pIdx is the constraint that failed and iCur is a
** cursor points to the conflicting row.
*/
SQLITE_PRIVATE void sqlite3UpsertDoUpdate(
Parse *pParse, /* The parsing and code-generating context */
Upsert *pUpsert, /* The ON CONFLICT clause for the upsert */
Table *pTab, /* The table being updated */
Index *pIdx, /* The UNIQUE constraint that failed */
int iCur /* Cursor for pIdx (or pTab if pIdx==NULL) */
){
Vdbe *v = pParse->pVdbe;
sqlite3 *db = pParse->db;
SrcList *pSrc; /* FROM clause for the UPDATE */
int iDataCur;
int i;
assert( v!=0 );
assert( pUpsert!=0 );
VdbeNoopComment((v, "Begin DO UPDATE of UPSERT"));
iDataCur = pUpsert->iDataCur;
if( pIdx && iCur!=iDataCur ){
if( HasRowid(pTab) ){
int regRowid = sqlite3GetTempReg(pParse);
sqlite3VdbeAddOp2(v, OP_IdxRowid, iCur, regRowid);
sqlite3VdbeAddOp3(v, OP_SeekRowid, iDataCur, 0, regRowid);
VdbeCoverage(v);
sqlite3ReleaseTempReg(pParse, regRowid);
}else{
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
int nPk = pPk->nKeyCol;
int iPk = pParse->nMem+1;
pParse->nMem += nPk;
for(i=0; i<nPk; i++){
int k;
assert( pPk->aiColumn[i]>=0 );
k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[i]);
sqlite3VdbeAddOp3(v, OP_Column, iCur, k, iPk+i);
VdbeComment((v, "%s.%s", pIdx->zName,
pTab->aCol[pPk->aiColumn[i]].zName));
}
sqlite3VdbeVerifyAbortable(v, OE_Abort);
i = sqlite3VdbeAddOp4Int(v, OP_Found, iDataCur, 0, iPk, nPk);
VdbeCoverage(v);
sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CORRUPT, OE_Abort, 0,
"corrupt database", P4_STATIC);
sqlite3MayAbort(pParse);
sqlite3VdbeJumpHere(v, i);
}
}
/* pUpsert does not own pUpsertSrc - the outer INSERT statement does. So
** we have to make a copy before passing it down into sqlite3Update() */
pSrc = sqlite3SrcListDup(db, pUpsert->pUpsertSrc, 0);
/* excluded.* columns of type REAL need to be converted to a hard real */
for(i=0; i<pTab->nCol; i++){
if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){
sqlite3VdbeAddOp1(v, OP_RealAffinity, pUpsert->regData+i);
}
}
sqlite3Update(pParse, pSrc, pUpsert->pUpsertSet,
pUpsert->pUpsertWhere, OE_Abort, 0, 0, pUpsert);
pUpsert->pUpsertSet = 0; /* Will have been deleted by sqlite3Update() */
pUpsert->pUpsertWhere = 0; /* Will have been deleted by sqlite3Update() */
VdbeNoopComment((v, "End DO UPDATE of UPSERT"));
}
#endif /* SQLITE_OMIT_UPSERT */
/************** End of upsert.c **********************************************/
/************** Begin file vacuum.c ******************************************/
/*
** 2003 April 6
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the VACUUM command.
**
** Most of the code in this file may be omitted by defining the
** SQLITE_OMIT_VACUUM macro.
*/
/* #include "sqliteInt.h" */
/* #include "vdbeInt.h" */
#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
/*
** Execute zSql on database db.
**
** If zSql returns rows, then each row will have exactly one
** column. (This will only happen if zSql begins with "SELECT".)
** Take each row of result and call execSql() again recursively.
**
** The execSqlF() routine does the same thing, except it accepts
** a format string as its third argument
*/
static int execSql(sqlite3 *db, char **pzErrMsg, const char *zSql){
sqlite3_stmt *pStmt;
int rc;
/* printf("SQL: [%s]\n", zSql); fflush(stdout); */
rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
if( rc!=SQLITE_OK ) return rc;
while( SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
const char *zSubSql = (const char*)sqlite3_column_text(pStmt,0);
assert( sqlite3_strnicmp(zSql,"SELECT",6)==0 );
/* The secondary SQL must be one of CREATE TABLE, CREATE INDEX,
** or INSERT. Historically there have been attacks that first
** corrupt the sqlite_schema.sql field with other kinds of statements
** then run VACUUM to get those statements to execute at inappropriate
** times. */
if( zSubSql
&& (strncmp(zSubSql,"CRE",3)==0 || strncmp(zSubSql,"INS",3)==0)
){
rc = execSql(db, pzErrMsg, zSubSql);
if( rc!=SQLITE_OK ) break;
}
}
assert( rc!=SQLITE_ROW );
if( rc==SQLITE_DONE ) rc = SQLITE_OK;
if( rc ){
sqlite3SetString(pzErrMsg, db, sqlite3_errmsg(db));
}
(void)sqlite3_finalize(pStmt);
return rc;
}
static int execSqlF(sqlite3 *db, char **pzErrMsg, const char *zSql, ...){
char *z;
va_list ap;
int rc;
va_start(ap, zSql);
z = sqlite3VMPrintf(db, zSql, ap);
va_end(ap);
if( z==0 ) return SQLITE_NOMEM;
rc = execSql(db, pzErrMsg, z);
sqlite3DbFree(db, z);
return rc;
}
/*
** The VACUUM command is used to clean up the database,
** collapse free space, etc. It is modelled after the VACUUM command
** in PostgreSQL. The VACUUM command works as follows:
**
** (1) Create a new transient database file
** (2) Copy all content from the database being vacuumed into
** the new transient database file
** (3) Copy content from the transient database back into the
** original database.
**
** The transient database requires temporary disk space approximately
** equal to the size of the original database. The copy operation of
** step (3) requires additional temporary disk space approximately equal
** to the size of the original database for the rollback journal.
** Hence, temporary disk space that is approximately 2x the size of the
** original database is required. Every page of the database is written
** approximately 3 times: Once for step (2) and twice for step (3).
** Two writes per page are required in step (3) because the original
** database content must be written into the rollback journal prior to
** overwriting the database with the vacuumed content.
**
** Only 1x temporary space and only 1x writes would be required if
** the copy of step (3) were replaced by deleting the original database
** and renaming the transient database as the original. But that will
** not work if other processes are attached to the original database.
** And a power loss in between deleting the original and renaming the
** transient would cause the database file to appear to be deleted
** following reboot.
*/
SQLITE_PRIVATE void sqlite3Vacuum(Parse *pParse, Token *pNm, Expr *pInto){
Vdbe *v = sqlite3GetVdbe(pParse);
int iDb = 0;
if( v==0 ) goto build_vacuum_end;
if( pParse->nErr ) goto build_vacuum_end;
if( pNm ){
#ifndef SQLITE_BUG_COMPATIBLE_20160819
/* Default behavior: Report an error if the argument to VACUUM is
** not recognized */
iDb = sqlite3TwoPartName(pParse, pNm, pNm, &pNm);
if( iDb<0 ) goto build_vacuum_end;
#else
/* When SQLITE_BUG_COMPATIBLE_20160819 is defined, unrecognized arguments
** to VACUUM are silently ignored. This is a back-out of a bug fix that
** occurred on 2016-08-19 (https://www.sqlite.org/src/info/083f9e6270).
** The buggy behavior is required for binary compatibility with some
** legacy applications. */
iDb = sqlite3FindDb(pParse->db, pNm);
if( iDb<0 ) iDb = 0;
#endif
}
if( iDb!=1 ){
int iIntoReg = 0;
if( pInto && sqlite3ResolveSelfReference(pParse,0,0,pInto,0)==0 ){
iIntoReg = ++pParse->nMem;
sqlite3ExprCode(pParse, pInto, iIntoReg);
}
sqlite3VdbeAddOp2(v, OP_Vacuum, iDb, iIntoReg);
sqlite3VdbeUsesBtree(v, iDb);
}
build_vacuum_end:
sqlite3ExprDelete(pParse->db, pInto);
return;
}
/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/
SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3RunVacuum(
char **pzErrMsg, /* Write error message here */
sqlite3 *db, /* Database connection */
int iDb, /* Which attached DB to vacuum */
sqlite3_value *pOut /* Write results here, if not NULL. VACUUM INTO */
){
int rc = SQLITE_OK; /* Return code from service routines */
Btree *pMain; /* The database being vacuumed */
Btree *pTemp; /* The temporary database we vacuum into */
u32 saved_mDbFlags; /* Saved value of db->mDbFlags */
u64 saved_flags; /* Saved value of db->flags */
int saved_nChange; /* Saved value of db->nChange */
int saved_nTotalChange; /* Saved value of db->nTotalChange */
u32 saved_openFlags; /* Saved value of db->openFlags */
u8 saved_mTrace; /* Saved trace settings */
Db *pDb = 0; /* Database to detach at end of vacuum */
int isMemDb; /* True if vacuuming a :memory: database */
int nRes; /* Bytes of reserved space at the end of each page */
int nDb; /* Number of attached databases */
const char *zDbMain; /* Schema name of database to vacuum */
const char *zOut; /* Name of output file */
if( !db->autoCommit ){
sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
return SQLITE_ERROR; /* IMP: R-12218-18073 */
}
if( db->nVdbeActive>1 ){
sqlite3SetString(pzErrMsg, db,"cannot VACUUM - SQL statements in progress");
return SQLITE_ERROR; /* IMP: R-15610-35227 */
}
saved_openFlags = db->openFlags;
if( pOut ){
if( sqlite3_value_type(pOut)!=SQLITE_TEXT ){
sqlite3SetString(pzErrMsg, db, "non-text filename");
return SQLITE_ERROR;
}
zOut = (const char*)sqlite3_value_text(pOut);
db->openFlags &= ~SQLITE_OPEN_READONLY;
db->openFlags |= SQLITE_OPEN_CREATE|SQLITE_OPEN_READWRITE;
}else{
zOut = "";
}
/* Save the current value of the database flags so that it can be
** restored before returning. Then set the writable-schema flag, and
** disable CHECK and foreign key constraints. */
saved_flags = db->flags;
saved_mDbFlags = db->mDbFlags;
saved_nChange = db->nChange;
saved_nTotalChange = db->nTotalChange;
saved_mTrace = db->mTrace;
db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;
db->mDbFlags |= DBFLAG_PreferBuiltin | DBFLAG_Vacuum;
db->flags &= ~(u64)(SQLITE_ForeignKeys | SQLITE_ReverseOrder
| SQLITE_Defensive | SQLITE_CountRows);
db->mTrace = 0;
zDbMain = db->aDb[iDb].zDbSName;
pMain = db->aDb[iDb].pBt;
isMemDb = sqlite3PagerIsMemdb(sqlite3BtreePager(pMain));
/* Attach the temporary database as 'vacuum_db'. The synchronous pragma
** can be set to 'off' for this file, as it is not recovered if a crash
** occurs anyway. The integrity of the database is maintained by a
** (possibly synchronous) transaction opened on the main database before
** sqlite3BtreeCopyFile() is called.
**
** An optimisation would be to use a non-journaled pager.
** (Later:) I tried setting "PRAGMA vacuum_db.journal_mode=OFF" but
** that actually made the VACUUM run slower. Very little journalling
** actually occurs when doing a vacuum since the vacuum_db is initially
** empty. Only the journal header is written. Apparently it takes more
** time to parse and run the PRAGMA to turn journalling off than it does
** to write the journal header file.
*/
nDb = db->nDb;
rc = execSqlF(db, pzErrMsg, "ATTACH %Q AS vacuum_db", zOut);
db->openFlags = saved_openFlags;
if( rc!=SQLITE_OK ) goto end_of_vacuum;
assert( (db->nDb-1)==nDb );
pDb = &db->aDb[nDb];
assert( strcmp(pDb->zDbSName,"vacuum_db")==0 );
pTemp = pDb->pBt;
if( pOut ){
sqlite3_file *id = sqlite3PagerFile(sqlite3BtreePager(pTemp));
i64 sz = 0;
if( id->pMethods!=0 && (sqlite3OsFileSize(id, &sz)!=SQLITE_OK || sz>0) ){
rc = SQLITE_ERROR;
sqlite3SetString(pzErrMsg, db, "output file already exists");
goto end_of_vacuum;
}
db->mDbFlags |= DBFLAG_VacuumInto;
}
nRes = sqlite3BtreeGetRequestedReserve(pMain);
sqlite3BtreeSetCacheSize(pTemp, db->aDb[iDb].pSchema->cache_size);
sqlite3BtreeSetSpillSize(pTemp, sqlite3BtreeSetSpillSize(pMain,0));
sqlite3BtreeSetPagerFlags(pTemp, PAGER_SYNCHRONOUS_OFF|PAGER_CACHESPILL);
/* Begin a transaction and take an exclusive lock on the main database
** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,
** to ensure that we do not try to change the page-size on a WAL database.
*/
rc = execSql(db, pzErrMsg, "BEGIN");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeBeginTrans(pMain, pOut==0 ? 2 : 0, 0);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Do not attempt to change the page size for a WAL database */
if( sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))
==PAGER_JOURNALMODE_WAL ){
db->nextPagesize = 0;
}
if( sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes, 0)
|| (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
|| NEVER(db->mallocFailed)
){
rc = SQLITE_NOMEM_BKPT;
goto end_of_vacuum;
}
#ifndef SQLITE_OMIT_AUTOVACUUM
sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac>=0 ? db->nextAutovac :
sqlite3BtreeGetAutoVacuum(pMain));
#endif
/* Query the schema of the main database. Create a mirror schema
** in the temporary database.
*/
db->init.iDb = nDb; /* force new CREATE statements into vacuum_db */
rc = execSqlF(db, pzErrMsg,
"SELECT sql FROM \"%w\".sqlite_schema"
" WHERE type='table'AND name<>'sqlite_sequence'"
" AND coalesce(rootpage,1)>0",
zDbMain
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execSqlF(db, pzErrMsg,
"SELECT sql FROM \"%w\".sqlite_schema"
" WHERE type='index'",
zDbMain
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
db->init.iDb = 0;
/* Loop through the tables in the main database. For each, do
** an "INSERT INTO vacuum_db.xxx SELECT * FROM main.xxx;" to copy
** the contents to the temporary database.
*/
rc = execSqlF(db, pzErrMsg,
"SELECT'INSERT INTO vacuum_db.'||quote(name)"
"||' SELECT*FROM\"%w\".'||quote(name)"
"FROM vacuum_db.sqlite_schema "
"WHERE type='table'AND coalesce(rootpage,1)>0",
zDbMain
);
assert( (db->mDbFlags & DBFLAG_Vacuum)!=0 );
db->mDbFlags &= ~DBFLAG_Vacuum;
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy the triggers, views, and virtual tables from the main database
** over to the temporary database. None of these objects has any
** associated storage, so all we have to do is copy their entries
** from the schema table.
*/
rc = execSqlF(db, pzErrMsg,
"INSERT INTO vacuum_db.sqlite_schema"
" SELECT*FROM \"%w\".sqlite_schema"
" WHERE type IN('view','trigger')"
" OR(type='table'AND rootpage=0)",
zDbMain
);
if( rc ) goto end_of_vacuum;
/* At this point, there is a write transaction open on both the
** vacuum database and the main database. Assuming no error occurs,
** both transactions are closed by this block - the main database
** transaction by sqlite3BtreeCopyFile() and the other by an explicit
** call to sqlite3BtreeCommit().
*/
{
u32 meta;
int i;
/* This array determines which meta meta values are preserved in the
** vacuum. Even entries are the meta value number and odd entries
** are an increment to apply to the meta value after the vacuum.
** The increment is used to increase the schema cookie so that other
** connections to the same database will know to reread the schema.
*/
static const unsigned char aCopy[] = {
BTREE_SCHEMA_VERSION, 1, /* Add one to the old schema cookie */
BTREE_DEFAULT_CACHE_SIZE, 0, /* Preserve the default page cache size */
BTREE_TEXT_ENCODING, 0, /* Preserve the text encoding */
BTREE_USER_VERSION, 0, /* Preserve the user version */
BTREE_APPLICATION_ID, 0, /* Preserve the application id */
};
assert( SQLITE_TXN_WRITE==sqlite3BtreeTxnState(pTemp) );
assert( pOut!=0 || SQLITE_TXN_WRITE==sqlite3BtreeTxnState(pMain) );
/* Copy Btree meta values */
for(i=0; i<ArraySize(aCopy); i+=2){
/* GetMeta() and UpdateMeta() cannot fail in this context because
** we already have page 1 loaded into cache and marked dirty. */
sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);
if( NEVER(rc!=SQLITE_OK) ) goto end_of_vacuum;
}
if( pOut==0 ){
rc = sqlite3BtreeCopyFile(pMain, pTemp);
}
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pOut==0 ){
sqlite3BtreeSetAutoVacuum(pMain, sqlite3BtreeGetAutoVacuum(pTemp));
}
#endif
}
assert( rc==SQLITE_OK );
if( pOut==0 ){
rc = sqlite3BtreeSetPageSize(pMain, sqlite3BtreeGetPageSize(pTemp), nRes,1);
}
end_of_vacuum:
/* Restore the original value of db->flags */
db->init.iDb = 0;
db->mDbFlags = saved_mDbFlags;
db->flags = saved_flags;
db->nChange = saved_nChange;
db->nTotalChange = saved_nTotalChange;
db->mTrace = saved_mTrace;
sqlite3BtreeSetPageSize(pMain, -1, 0, 1);
/* Currently there is an SQL level transaction open on the vacuum
** database. No locks are held on any other files (since the main file
** was committed at the btree level). So it safe to end the transaction
** by manually setting the autoCommit flag to true and detaching the
** vacuum database. The vacuum_db journal file is deleted when the pager
** is closed by the DETACH.
*/
db->autoCommit = 1;
if( pDb ){
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
pDb->pSchema = 0;
}
/* This both clears the schemas and reduces the size of the db->aDb[]
** array. */
sqlite3ResetAllSchemasOfConnection(db);
return rc;
}
#endif /* SQLITE_OMIT_VACUUM && SQLITE_OMIT_ATTACH */
/************** End of vacuum.c **********************************************/
/************** Begin file vtab.c ********************************************/
/*
** 2006 June 10
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to help implement virtual tables.
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* #include "sqliteInt.h" */
/*
** Before a virtual table xCreate() or xConnect() method is invoked, the
** sqlite3.pVtabCtx member variable is set to point to an instance of
** this struct allocated on the stack. It is used by the implementation of
** the sqlite3_declare_vtab() and sqlite3_vtab_config() APIs, both of which
** are invoked only from within xCreate and xConnect methods.
*/
struct VtabCtx {
VTable *pVTable; /* The virtual table being constructed */
Table *pTab; /* The Table object to which the virtual table belongs */
VtabCtx *pPrior; /* Parent context (if any) */
int bDeclared; /* True after sqlite3_declare_vtab() is called */
};
/*
** Construct and install a Module object for a virtual table. When this
** routine is called, it is guaranteed that all appropriate locks are held
** and the module is not already part of the connection.
**
** If there already exists a module with zName, replace it with the new one.
** If pModule==0, then delete the module zName if it exists.
*/
SQLITE_PRIVATE Module *sqlite3VtabCreateModule(
sqlite3 *db, /* Database in which module is registered */
const char *zName, /* Name assigned to this module */
const sqlite3_module *pModule, /* The definition of the module */
void *pAux, /* Context pointer for xCreate/xConnect */
void (*xDestroy)(void *) /* Module destructor function */
){
Module *pMod;
Module *pDel;
char *zCopy;
if( pModule==0 ){
zCopy = (char*)zName;
pMod = 0;
}else{
int nName = sqlite3Strlen30(zName);
pMod = (Module *)sqlite3Malloc(sizeof(Module) + nName + 1);
if( pMod==0 ){
sqlite3OomFault(db);
return 0;
}
zCopy = (char *)(&pMod[1]);
memcpy(zCopy, zName, nName+1);
pMod->zName = zCopy;
pMod->pModule = pModule;
pMod->pAux = pAux;
pMod->xDestroy = xDestroy;
pMod->pEpoTab = 0;
pMod->nRefModule = 1;
}
pDel = (Module *)sqlite3HashInsert(&db->aModule,zCopy,(void*)pMod);
if( pDel ){
if( pDel==pMod ){
sqlite3OomFault(db);
sqlite3DbFree(db, pDel);
pMod = 0;
}else{
sqlite3VtabEponymousTableClear(db, pDel);
sqlite3VtabModuleUnref(db, pDel);
}
}
return pMod;
}
/*
** The actual function that does the work of creating a new module.
** This function implements the sqlite3_create_module() and
** sqlite3_create_module_v2() interfaces.
*/
static int createModule(
sqlite3 *db, /* Database in which module is registered */
const char *zName, /* Name assigned to this module */
const sqlite3_module *pModule, /* The definition of the module */
void *pAux, /* Context pointer for xCreate/xConnect */
void (*xDestroy)(void *) /* Module destructor function */
){
int rc = SQLITE_OK;
sqlite3_mutex_enter(db->mutex);
(void)sqlite3VtabCreateModule(db, zName, pModule, pAux, xDestroy);
rc = sqlite3ApiExit(db, rc);
if( rc!=SQLITE_OK && xDestroy ) xDestroy(pAux);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** External API function used to create a new virtual-table module.
*/
SQLITE_API int SQLITE_APICALL sqlite3_create_module(
sqlite3 *db, /* Database in which module is registered */
const char *zName, /* Name assigned to this module */
const sqlite3_module *pModule, /* The definition of the module */
void *pAux /* Context pointer for xCreate/xConnect */
){
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
#endif
return createModule(db, zName, pModule, pAux, 0);
}
/*
** External API function used to create a new virtual-table module.
*/
SQLITE_API int SQLITE_APICALL sqlite3_create_module_v2(
sqlite3 *db, /* Database in which module is registered */
const char *zName, /* Name assigned to this module */
const sqlite3_module *pModule, /* The definition of the module */
void *pAux, /* Context pointer for xCreate/xConnect */
void (*xDestroy)(void *) /* Module destructor function */
){
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
#endif
return createModule(db, zName, pModule, pAux, xDestroy);
}
/*
** External API to drop all virtual-table modules, except those named
** on the azNames list.
*/
SQLITE_API int SQLITE_APICALL sqlite3_drop_modules(sqlite3 *db, const char** azNames){
HashElem *pThis, *pNext;
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
for(pThis=sqliteHashFirst(&db->aModule); pThis; pThis=pNext){
Module *pMod = (Module*)sqliteHashData(pThis);
pNext = sqliteHashNext(pThis);
if( azNames ){
int ii;
for(ii=0; azNames[ii]!=0 && strcmp(azNames[ii],pMod->zName)!=0; ii++){}
if( azNames[ii]!=0 ) continue;
}
createModule(db, pMod->zName, 0, 0, 0);
}
return SQLITE_OK;
}
/*
** Decrement the reference count on a Module object. Destroy the
** module when the reference count reaches zero.
*/
SQLITE_PRIVATE void sqlite3VtabModuleUnref(sqlite3 *db, Module *pMod){
assert( pMod->nRefModule>0 );
pMod->nRefModule--;
if( pMod->nRefModule==0 ){
if( pMod->xDestroy ){
pMod->xDestroy(pMod->pAux);
}
assert( pMod->pEpoTab==0 );
sqlite3DbFree(db, pMod);
}
}
/*
** Lock the virtual table so that it cannot be disconnected.
** Locks nest. Every lock should have a corresponding unlock.
** If an unlock is omitted, resources leaks will occur.
**
** If a disconnect is attempted while a virtual table is locked,
** the disconnect is deferred until all locks have been removed.
*/
SQLITE_PRIVATE void sqlite3VtabLock(VTable *pVTab){
pVTab->nRef++;
}
/*
** pTab is a pointer to a Table structure representing a virtual-table.
** Return a pointer to the VTable object used by connection db to access
** this virtual-table, if one has been created, or NULL otherwise.
*/
SQLITE_PRIVATE VTable *sqlite3GetVTable(sqlite3 *db, Table *pTab){
VTable *pVtab;
assert( IsVirtual(pTab) );
for(pVtab=pTab->pVTable; pVtab && pVtab->db!=db; pVtab=pVtab->pNext);
return pVtab;
}
/*
** Decrement the ref-count on a virtual table object. When the ref-count
** reaches zero, call the xDisconnect() method to delete the object.
*/
SQLITE_PRIVATE void sqlite3VtabUnlock(VTable *pVTab){
sqlite3 *db = pVTab->db;
assert( db );
assert( pVTab->nRef>0 );
assert( db->magic==SQLITE_MAGIC_OPEN || db->magic==SQLITE_MAGIC_ZOMBIE );
pVTab->nRef--;
if( pVTab->nRef==0 ){
sqlite3_vtab *p = pVTab->pVtab;
sqlite3VtabModuleUnref(pVTab->db, pVTab->pMod);
if( p ){
p->pModule->xDisconnect(p);
}
sqlite3DbFree(db, pVTab);
}
}
/*
** Table p is a virtual table. This function moves all elements in the
** p->pVTable list to the sqlite3.pDisconnect lists of their associated
** database connections to be disconnected at the next opportunity.
** Except, if argument db is not NULL, then the entry associated with
** connection db is left in the p->pVTable list.
*/
static VTable *vtabDisconnectAll(sqlite3 *db, Table *p){
VTable *pRet = 0;
VTable *pVTable = p->pVTable;
p->pVTable = 0;
/* Assert that the mutex (if any) associated with the BtShared database
** that contains table p is held by the caller. See header comments
** above function sqlite3VtabUnlockList() for an explanation of why
** this makes it safe to access the sqlite3.pDisconnect list of any
** database connection that may have an entry in the p->pVTable list.
*/
assert( db==0 || sqlite3SchemaMutexHeld(db, 0, p->pSchema) );
while( pVTable ){
sqlite3 *db2 = pVTable->db;
VTable *pNext = pVTable->pNext;
assert( db2 );
if( db2==db ){
pRet = pVTable;
p->pVTable = pRet;
pRet->pNext = 0;
}else{
pVTable->pNext = db2->pDisconnect;
db2->pDisconnect = pVTable;
}
pVTable = pNext;
}
assert( !db || pRet );
return pRet;
}
/*
** Table *p is a virtual table. This function removes the VTable object
** for table *p associated with database connection db from the linked
** list in p->pVTab. It also decrements the VTable ref count. This is
** used when closing database connection db to free all of its VTable
** objects without disturbing the rest of the Schema object (which may
** be being used by other shared-cache connections).
*/
SQLITE_PRIVATE void sqlite3VtabDisconnect(sqlite3 *db, Table *p){
VTable **ppVTab;
assert( IsVirtual(p) );
assert( sqlite3BtreeHoldsAllMutexes(db) );
assert( sqlite3_mutex_held(db->mutex) );
for(ppVTab=&p->pVTable; *ppVTab; ppVTab=&(*ppVTab)->pNext){
if( (*ppVTab)->db==db ){
VTable *pVTab = *ppVTab;
*ppVTab = pVTab->pNext;
sqlite3VtabUnlock(pVTab);
break;
}
}
}
/*
** Disconnect all the virtual table objects in the sqlite3.pDisconnect list.
**
** This function may only be called when the mutexes associated with all
** shared b-tree databases opened using connection db are held by the
** caller. This is done to protect the sqlite3.pDisconnect list. The
** sqlite3.pDisconnect list is accessed only as follows:
**
** 1) By this function. In this case, all BtShared mutexes and the mutex
** associated with the database handle itself must be held.
**
** 2) By function vtabDisconnectAll(), when it adds a VTable entry to
** the sqlite3.pDisconnect list. In this case either the BtShared mutex
** associated with the database the virtual table is stored in is held
** or, if the virtual table is stored in a non-sharable database, then
** the database handle mutex is held.
**
** As a result, a sqlite3.pDisconnect cannot be accessed simultaneously
** by multiple threads. It is thread-safe.
*/
SQLITE_PRIVATE void sqlite3VtabUnlockList(sqlite3 *db){
VTable *p = db->pDisconnect;
assert( sqlite3BtreeHoldsAllMutexes(db) );
assert( sqlite3_mutex_held(db->mutex) );
if( p ){
db->pDisconnect = 0;
sqlite3ExpirePreparedStatements(db, 0);
do {
VTable *pNext = p->pNext;
sqlite3VtabUnlock(p);
p = pNext;
}while( p );
}
}
/*
** Clear any and all virtual-table information from the Table record.
** This routine is called, for example, just before deleting the Table
** record.
**
** Since it is a virtual-table, the Table structure contains a pointer
** to the head of a linked list of VTable structures. Each VTable
** structure is associated with a single sqlite3* user of the schema.
** The reference count of the VTable structure associated with database
** connection db is decremented immediately (which may lead to the
** structure being xDisconnected and free). Any other VTable structures
** in the list are moved to the sqlite3.pDisconnect list of the associated
** database connection.
*/
SQLITE_PRIVATE void sqlite3VtabClear(sqlite3 *db, Table *p){
if( !db || db->pnBytesFreed==0 ) vtabDisconnectAll(0, p);
if( p->azModuleArg ){
int i;
for(i=0; i<p->nModuleArg; i++){
if( i!=1 ) sqlite3DbFree(db, p->azModuleArg[i]);
}
sqlite3DbFree(db, p->azModuleArg);
}
}
/*
** Add a new module argument to pTable->azModuleArg[].
** The string is not copied - the pointer is stored. The
** string will be freed automatically when the table is
** deleted.
*/
static void addModuleArgument(Parse *pParse, Table *pTable, char *zArg){
sqlite3_int64 nBytes = sizeof(char *)*(2+pTable->nModuleArg);
char **azModuleArg;
sqlite3 *db = pParse->db;
if( pTable->nModuleArg+3>=db->aLimit[SQLITE_LIMIT_COLUMN] ){
sqlite3ErrorMsg(pParse, "too many columns on %s", pTable->zName);
}
azModuleArg = sqlite3DbRealloc(db, pTable->azModuleArg, nBytes);
if( azModuleArg==0 ){
sqlite3DbFree(db, zArg);
}else{
int i = pTable->nModuleArg++;
azModuleArg[i] = zArg;
azModuleArg[i+1] = 0;
pTable->azModuleArg = azModuleArg;
}
}
/*
** The parser calls this routine when it first sees a CREATE VIRTUAL TABLE
** statement. The module name has been parsed, but the optional list
** of parameters that follow the module name are still pending.
*/
SQLITE_PRIVATE void sqlite3VtabBeginParse(
Parse *pParse, /* Parsing context */
Token *pName1, /* Name of new table, or database name */
Token *pName2, /* Name of new table or NULL */
Token *pModuleName, /* Name of the module for the virtual table */
int ifNotExists /* No error if the table already exists */
){
Table *pTable; /* The new virtual table */
sqlite3 *db; /* Database connection */
sqlite3StartTable(pParse, pName1, pName2, 0, 0, 1, ifNotExists);
pTable = pParse->pNewTable;
if( pTable==0 ) return;
assert( 0==pTable->pIndex );
db = pParse->db;
assert( pTable->nModuleArg==0 );
addModuleArgument(pParse, pTable, sqlite3NameFromToken(db, pModuleName));
addModuleArgument(pParse, pTable, 0);
addModuleArgument(pParse, pTable, sqlite3DbStrDup(db, pTable->zName));
assert( (pParse->sNameToken.z==pName2->z && pName2->z!=0)
|| (pParse->sNameToken.z==pName1->z && pName2->z==0)
);
pParse->sNameToken.n = (int)(
&pModuleName->z[pModuleName->n] - pParse->sNameToken.z
);
#ifndef SQLITE_OMIT_AUTHORIZATION
/* Creating a virtual table invokes the authorization callback twice.
** The first invocation, to obtain permission to INSERT a row into the
** sqlite_schema table, has already been made by sqlite3StartTable().
** The second call, to obtain permission to create the table, is made now.
*/
if( pTable->azModuleArg ){
int iDb = sqlite3SchemaToIndex(db, pTable->pSchema);
assert( iDb>=0 ); /* The database the table is being created in */
sqlite3AuthCheck(pParse, SQLITE_CREATE_VTABLE, pTable->zName,
pTable->azModuleArg[0], pParse->db->aDb[iDb].zDbSName);
}
#endif
}
/*
** This routine takes the module argument that has been accumulating
** in pParse->zArg[] and appends it to the list of arguments on the
** virtual table currently under construction in pParse->pTable.
*/
static void addArgumentToVtab(Parse *pParse){
if( pParse->sArg.z && pParse->pNewTable ){
const char *z = (const char*)pParse->sArg.z;
int n = pParse->sArg.n;
sqlite3 *db = pParse->db;
addModuleArgument(pParse, pParse->pNewTable, sqlite3DbStrNDup(db, z, n));
}
}
/*
** The parser calls this routine after the CREATE VIRTUAL TABLE statement
** has been completely parsed.
*/
SQLITE_PRIVATE void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
Table *pTab = pParse->pNewTable; /* The table being constructed */
sqlite3 *db = pParse->db; /* The database connection */
if( pTab==0 ) return;
addArgumentToVtab(pParse);
pParse->sArg.z = 0;
if( pTab->nModuleArg<1 ) return;
/* If the CREATE VIRTUAL TABLE statement is being entered for the
** first time (in other words if the virtual table is actually being
** created now instead of just being read out of sqlite_schema) then
** do additional initialization work and store the statement text
** in the sqlite_schema table.
*/
if( !db->init.busy ){
char *zStmt;
char *zWhere;
int iDb;
int iReg;
Vdbe *v;
sqlite3MayAbort(pParse);
/* Compute the complete text of the CREATE VIRTUAL TABLE statement */
if( pEnd ){
pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n;
}
zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);
/* A slot for the record has already been allocated in the
** schema table. We just need to update that slot with all
** the information we've collected.
**
** The VM register number pParse->regRowid holds the rowid of an
** entry in the sqlite_schema table tht was created for this vtab
** by sqlite3StartTable().
*/
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3NestedParse(pParse,
"UPDATE %Q." DFLT_SCHEMA_TABLE " "
"SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
"WHERE rowid=#%d",
db->aDb[iDb].zDbSName,
pTab->zName,
pTab->zName,
zStmt,
pParse->regRowid
);
v = sqlite3GetVdbe(pParse);
sqlite3ChangeCookie(pParse, iDb);
sqlite3VdbeAddOp0(v, OP_Expire);
zWhere = sqlite3MPrintf(db, "name=%Q AND sql=%Q", pTab->zName, zStmt);
sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);
sqlite3DbFree(db, zStmt);
iReg = ++pParse->nMem;
sqlite3VdbeLoadString(v, iReg, pTab->zName);
sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg);
}
/* If we are rereading the sqlite_schema table create the in-memory
** record of the table. The xConnect() method is not called until
** the first time the virtual table is used in an SQL statement. This
** allows a schema that contains virtual tables to be loaded before
** the required virtual table implementations are registered. */
else {
Table *pOld;
Schema *pSchema = pTab->pSchema;
const char *zName = pTab->zName;
assert( sqlite3SchemaMutexHeld(db, 0, pSchema) );
pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab);
if( pOld ){
sqlite3OomFault(db);
assert( pTab==pOld ); /* Malloc must have failed inside HashInsert() */
return;
}
pParse->pNewTable = 0;
}
}
/*
** The parser calls this routine when it sees the first token
** of an argument to the module name in a CREATE VIRTUAL TABLE statement.
*/
SQLITE_PRIVATE void sqlite3VtabArgInit(Parse *pParse){
addArgumentToVtab(pParse);
pParse->sArg.z = 0;
pParse->sArg.n = 0;
}
/*
** The parser calls this routine for each token after the first token
** in an argument to the module name in a CREATE VIRTUAL TABLE statement.
*/
SQLITE_PRIVATE void sqlite3VtabArgExtend(Parse *pParse, Token *p){
Token *pArg = &pParse->sArg;
if( pArg->z==0 ){
pArg->z = p->z;
pArg->n = p->n;
}else{
assert(pArg->z <= p->z);
pArg->n = (int)(&p->z[p->n] - pArg->z);
}
}
/*
** Invoke a virtual table constructor (either xCreate or xConnect). The
** pointer to the function to invoke is passed as the fourth parameter
** to this procedure.
*/
static int vtabCallConstructor(
sqlite3 *db,
Table *pTab,
Module *pMod,
int (*xConstruct)(sqlite3*,void*,int,const char*const*,sqlite3_vtab**,char**),
char **pzErr
){
VtabCtx sCtx;
VTable *pVTable;
int rc;
const char *const*azArg = (const char *const*)pTab->azModuleArg;
int nArg = pTab->nModuleArg;
char *zErr = 0;
char *zModuleName;
int iDb;
VtabCtx *pCtx;
/* Check that the virtual-table is not already being initialized */
for(pCtx=db->pVtabCtx; pCtx; pCtx=pCtx->pPrior){
if( pCtx->pTab==pTab ){
*pzErr = sqlite3MPrintf(db,
"vtable constructor called recursively: %s", pTab->zName
);
return SQLITE_LOCKED;
}
}
zModuleName = sqlite3DbStrDup(db, pTab->zName);
if( !zModuleName ){
return SQLITE_NOMEM_BKPT;
}
pVTable = sqlite3MallocZero(sizeof(VTable));
if( !pVTable ){
sqlite3OomFault(db);
sqlite3DbFree(db, zModuleName);
return SQLITE_NOMEM_BKPT;
}
pVTable->db = db;
pVTable->pMod = pMod;
pVTable->eVtabRisk = SQLITE_VTABRISK_Normal;
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
pTab->azModuleArg[1] = db->aDb[iDb].zDbSName;
/* Invoke the virtual table constructor */
assert( &db->pVtabCtx );
assert( xConstruct );
sCtx.pTab = pTab;
sCtx.pVTable = pVTable;
sCtx.pPrior = db->pVtabCtx;
sCtx.bDeclared = 0;
db->pVtabCtx = &sCtx;
rc = xConstruct(db, pMod->pAux, nArg, azArg, &pVTable->pVtab, &zErr);
db->pVtabCtx = sCtx.pPrior;
if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
assert( sCtx.pTab==pTab );
if( SQLITE_OK!=rc ){
if( zErr==0 ){
*pzErr = sqlite3MPrintf(db, "vtable constructor failed: %s", zModuleName);
}else {
*pzErr = sqlite3MPrintf(db, "%s", zErr);
sqlite3_free(zErr);
}
sqlite3DbFree(db, pVTable);
}else if( ALWAYS(pVTable->pVtab) ){
/* Justification of ALWAYS(): A correct vtab constructor must allocate
** the sqlite3_vtab object if successful. */
memset(pVTable->pVtab, 0, sizeof(pVTable->pVtab[0]));
pVTable->pVtab->pModule = pMod->pModule;
pMod->nRefModule++;
pVTable->nRef = 1;
if( sCtx.bDeclared==0 ){
const char *zFormat = "vtable constructor did not declare schema: %s";
*pzErr = sqlite3MPrintf(db, zFormat, pTab->zName);
sqlite3VtabUnlock(pVTable);
rc = SQLITE_ERROR;
}else{
int iCol;
u16 oooHidden = 0;
/* If everything went according to plan, link the new VTable structure
** into the linked list headed by pTab->pVTable. Then loop through the
** columns of the table to see if any of them contain the token "hidden".
** If so, set the Column COLFLAG_HIDDEN flag and remove the token from
** the type string. */
pVTable->pNext = pTab->pVTable;
pTab->pVTable = pVTable;
for(iCol=0; iCol<pTab->nCol; iCol++){
char *zType = sqlite3ColumnType(&pTab->aCol[iCol], "");
int nType;
int i = 0;
nType = sqlite3Strlen30(zType);
for(i=0; i<nType; i++){
if( 0==sqlite3StrNICmp("hidden", &zType[i], 6)
&& (i==0 || zType[i-1]==' ')
&& (zType[i+6]=='\0' || zType[i+6]==' ')
){
break;
}
}
if( i<nType ){
int j;
int nDel = 6 + (zType[i+6] ? 1 : 0);
for(j=i; (j+nDel)<=nType; j++){
zType[j] = zType[j+nDel];
}
if( zType[i]=='\0' && i>0 ){
assert(zType[i-1]==' ');
zType[i-1] = '\0';
}
pTab->aCol[iCol].colFlags |= COLFLAG_HIDDEN;
oooHidden = TF_OOOHidden;
}else{
pTab->tabFlags |= oooHidden;
}
}
}
}
sqlite3DbFree(db, zModuleName);
return rc;
}
/*
** This function is invoked by the parser to call the xConnect() method
** of the virtual table pTab. If an error occurs, an error code is returned
** and an error left in pParse.
**
** This call is a no-op if table pTab is not a virtual table.
*/
SQLITE_PRIVATE int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
sqlite3 *db = pParse->db;
const char *zMod;
Module *pMod;
int rc;
assert( pTab );
if( !IsVirtual(pTab) || sqlite3GetVTable(db, pTab) ){
return SQLITE_OK;
}
/* Locate the required virtual table module */
zMod = pTab->azModuleArg[0];
pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
if( !pMod ){
const char *zModule = pTab->azModuleArg[0];
sqlite3ErrorMsg(pParse, "no such module: %s", zModule);
rc = SQLITE_ERROR;
}else{
char *zErr = 0;
rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xConnect, &zErr);
if( rc!=SQLITE_OK ){
sqlite3ErrorMsg(pParse, "%s", zErr);
pParse->rc = rc;
}
sqlite3DbFree(db, zErr);
}
return rc;
}
/*
** Grow the db->aVTrans[] array so that there is room for at least one
** more v-table. Return SQLITE_NOMEM if a malloc fails, or SQLITE_OK otherwise.
*/
static int growVTrans(sqlite3 *db){
const int ARRAY_INCR = 5;
/* Grow the sqlite3.aVTrans array if required */
if( (db->nVTrans%ARRAY_INCR)==0 ){
VTable **aVTrans;
sqlite3_int64 nBytes = sizeof(sqlite3_vtab*)*
((sqlite3_int64)db->nVTrans + ARRAY_INCR);
aVTrans = sqlite3DbRealloc(db, (void *)db->aVTrans, nBytes);
if( !aVTrans ){
return SQLITE_NOMEM_BKPT;
}
memset(&aVTrans[db->nVTrans], 0, sizeof(sqlite3_vtab *)*ARRAY_INCR);
db->aVTrans = aVTrans;
}
return SQLITE_OK;
}
/*
** Add the virtual table pVTab to the array sqlite3.aVTrans[]. Space should
** have already been reserved using growVTrans().
*/
static void addToVTrans(sqlite3 *db, VTable *pVTab){
/* Add pVtab to the end of sqlite3.aVTrans */
db->aVTrans[db->nVTrans++] = pVTab;
sqlite3VtabLock(pVTab);
}
/*
** This function is invoked by the vdbe to call the xCreate method
** of the virtual table named zTab in database iDb.
**
** If an error occurs, *pzErr is set to point to an English language
** description of the error and an SQLITE_XXX error code is returned.
** In this case the caller must call sqlite3DbFree(db, ) on *pzErr.
*/
SQLITE_PRIVATE int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
int rc = SQLITE_OK;
Table *pTab;
Module *pMod;
const char *zMod;
pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
assert( pTab && IsVirtual(pTab) && !pTab->pVTable );
/* Locate the required virtual table module */
zMod = pTab->azModuleArg[0];
pMod = (Module*)sqlite3HashFind(&db->aModule, zMod);
/* If the module has been registered and includes a Create method,
** invoke it now. If the module has not been registered, return an
** error. Otherwise, do nothing.
*/
if( pMod==0 || pMod->pModule->xCreate==0 || pMod->pModule->xDestroy==0 ){
*pzErr = sqlite3MPrintf(db, "no such module: %s", zMod);
rc = SQLITE_ERROR;
}else{
rc = vtabCallConstructor(db, pTab, pMod, pMod->pModule->xCreate, pzErr);
}
/* Justification of ALWAYS(): The xConstructor method is required to
** create a valid sqlite3_vtab if it returns SQLITE_OK. */
if( rc==SQLITE_OK && ALWAYS(sqlite3GetVTable(db, pTab)) ){
rc = growVTrans(db);
if( rc==SQLITE_OK ){
addToVTrans(db, sqlite3GetVTable(db, pTab));
}
}
return rc;
}
/*
** This function is used to set the schema of a virtual table. It is only
** valid to call this function from within the xCreate() or xConnect() of a
** virtual table module.
*/
SQLITE_API int SQLITE_APICALL sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
VtabCtx *pCtx;
int rc = SQLITE_OK;
Table *pTab;
char *zErr = 0;
Parse sParse;
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) || zCreateTable==0 ){
return SQLITE_MISUSE_BKPT;
}
#endif
sqlite3_mutex_enter(db->mutex);
pCtx = db->pVtabCtx;
if( !pCtx || pCtx->bDeclared ){
sqlite3Error(db, SQLITE_MISUSE);
sqlite3_mutex_leave(db->mutex);
return SQLITE_MISUSE_BKPT;
}
pTab = pCtx->pTab;
assert( IsVirtual(pTab) );
memset(&sParse, 0, sizeof(sParse));
sParse.eParseMode = PARSE_MODE_DECLARE_VTAB;
sParse.db = db;
sParse.nQueryLoop = 1;
if( SQLITE_OK==sqlite3RunParser(&sParse, zCreateTable, &zErr)
&& sParse.pNewTable
&& !db->mallocFailed
&& !sParse.pNewTable->pSelect
&& !IsVirtual(sParse.pNewTable)
){
if( !pTab->aCol ){
Table *pNew = sParse.pNewTable;
Index *pIdx;
pTab->aCol = pNew->aCol;
pTab->nCol = pNew->nCol;
pTab->tabFlags |= pNew->tabFlags & (TF_WithoutRowid|TF_NoVisibleRowid);
pNew->nCol = 0;
pNew->aCol = 0;
assert( pTab->pIndex==0 );
assert( HasRowid(pNew) || sqlite3PrimaryKeyIndex(pNew)!=0 );
if( !HasRowid(pNew)
&& pCtx->pVTable->pMod->pModule->xUpdate!=0
&& sqlite3PrimaryKeyIndex(pNew)->nKeyCol!=1
){
/* WITHOUT ROWID virtual tables must either be read-only (xUpdate==0)
** or else must have a single-column PRIMARY KEY */
rc = SQLITE_ERROR;
}
pIdx = pNew->pIndex;
if( pIdx ){
assert( pIdx->pNext==0 );
pTab->pIndex = pIdx;
pNew->pIndex = 0;
pIdx->pTable = pTab;
}
}
pCtx->bDeclared = 1;
}else{
sqlite3ErrorWithMsg(db, SQLITE_ERROR, (zErr ? "%s" : 0), zErr);
sqlite3DbFree(db, zErr);
rc = SQLITE_ERROR;
}
sParse.eParseMode = PARSE_MODE_NORMAL;
if( sParse.pVdbe ){
sqlite3VdbeFinalize(sParse.pVdbe);
}
sqlite3DeleteTable(db, sParse.pNewTable);
sqlite3ParserReset(&sParse);
assert( (rc&0xff)==rc );
rc = sqlite3ApiExit(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
/*
** This function is invoked by the vdbe to call the xDestroy method
** of the virtual table named zTab in database iDb. This occurs
** when a DROP TABLE is mentioned.
**
** This call is a no-op if zTab is not a virtual table.
*/
SQLITE_PRIVATE int sqlite3VtabCallDestroy(sqlite3 *db, int iDb, const char *zTab){
int rc = SQLITE_OK;
Table *pTab;
pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zDbSName);
if( pTab!=0 && ALWAYS(pTab->pVTable!=0) ){
VTable *p;
int (*xDestroy)(sqlite3_vtab *);
for(p=pTab->pVTable; p; p=p->pNext){
assert( p->pVtab );
if( p->pVtab->nRef>0 ){
return SQLITE_LOCKED;
}
}
p = vtabDisconnectAll(db, pTab);
xDestroy = p->pMod->pModule->xDestroy;
if( xDestroy==0 ) xDestroy = p->pMod->pModule->xDisconnect;
assert( xDestroy!=0 );
pTab->nTabRef++;
rc = xDestroy(p->pVtab);
/* Remove the sqlite3_vtab* from the aVTrans[] array, if applicable */
if( rc==SQLITE_OK ){
assert( pTab->pVTable==p && p->pNext==0 );
p->pVtab = 0;
pTab->pVTable = 0;
sqlite3VtabUnlock(p);
}
sqlite3DeleteTable(db, pTab);
}
return rc;
}
/*
** This function invokes either the xRollback or xCommit method
** of each of the virtual tables in the sqlite3.aVTrans array. The method
** called is identified by the second argument, "offset", which is
** the offset of the method to call in the sqlite3_module structure.
**
** The array is cleared after invoking the callbacks.
*/
static void callFinaliser(sqlite3 *db, int offset){
int i;
if( db->aVTrans ){
VTable **aVTrans = db->aVTrans;
db->aVTrans = 0;
for(i=0; i<db->nVTrans; i++){
VTable *pVTab = aVTrans[i];
sqlite3_vtab *p = pVTab->pVtab;
if( p ){
int (*x)(sqlite3_vtab *);
x = *(int (**)(sqlite3_vtab *))((char *)p->pModule + offset);
if( x ) x(p);
}
pVTab->iSavepoint = 0;
sqlite3VtabUnlock(pVTab);
}
sqlite3DbFree(db, aVTrans);
db->nVTrans = 0;
}
}
/*
** Invoke the xSync method of all virtual tables in the sqlite3.aVTrans
** array. Return the error code for the first error that occurs, or
** SQLITE_OK if all xSync operations are successful.
**
** If an error message is available, leave it in p->zErrMsg.
*/
SQLITE_PRIVATE int sqlite3VtabSync(sqlite3 *db, Vdbe *p){
int i;
int rc = SQLITE_OK;
VTable **aVTrans = db->aVTrans;
db->aVTrans = 0;
for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){
int (*x)(sqlite3_vtab *);
sqlite3_vtab *pVtab = aVTrans[i]->pVtab;
if( pVtab && (x = pVtab->pModule->xSync)!=0 ){
rc = x(pVtab);
sqlite3VtabImportErrmsg(p, pVtab);
}
}
db->aVTrans = aVTrans;
return rc;
}
/*
** Invoke the xRollback method of all virtual tables in the
** sqlite3.aVTrans array. Then clear the array itself.
*/
SQLITE_PRIVATE int sqlite3VtabRollback(sqlite3 *db){
callFinaliser(db, offsetof(sqlite3_module,xRollback));
return SQLITE_OK;
}
/*
** Invoke the xCommit method of all virtual tables in the
** sqlite3.aVTrans array. Then clear the array itself.
*/
SQLITE_PRIVATE int sqlite3VtabCommit(sqlite3 *db){
callFinaliser(db, offsetof(sqlite3_module,xCommit));
return SQLITE_OK;
}
/*
** If the virtual table pVtab supports the transaction interface
** (xBegin/xRollback/xCommit and optionally xSync) and a transaction is
** not currently open, invoke the xBegin method now.
**
** If the xBegin call is successful, place the sqlite3_vtab pointer
** in the sqlite3.aVTrans array.
*/
SQLITE_PRIVATE int sqlite3VtabBegin(sqlite3 *db, VTable *pVTab){
int rc = SQLITE_OK;
const sqlite3_module *pModule;
/* Special case: If db->aVTrans is NULL and db->nVTrans is greater
** than zero, then this function is being called from within a
** virtual module xSync() callback. It is illegal to write to
** virtual module tables in this case, so return SQLITE_LOCKED.
*/
if( sqlite3VtabInSync(db) ){
return SQLITE_LOCKED;
}
if( !pVTab ){
return SQLITE_OK;
}
pModule = pVTab->pVtab->pModule;
if( pModule->xBegin ){
int i;
/* If pVtab is already in the aVTrans array, return early */
for(i=0; i<db->nVTrans; i++){
if( db->aVTrans[i]==pVTab ){
return SQLITE_OK;
}
}
/* Invoke the xBegin method. If successful, add the vtab to the
** sqlite3.aVTrans[] array. */
rc = growVTrans(db);
if( rc==SQLITE_OK ){
rc = pModule->xBegin(pVTab->pVtab);
if( rc==SQLITE_OK ){
int iSvpt = db->nStatement + db->nSavepoint;
addToVTrans(db, pVTab);
if( iSvpt && pModule->xSavepoint ){
pVTab->iSavepoint = iSvpt;
rc = pModule->xSavepoint(pVTab->pVtab, iSvpt-1);
}
}
}
}
return rc;
}
/*
** Invoke either the xSavepoint, xRollbackTo or xRelease method of all
** virtual tables that currently have an open transaction. Pass iSavepoint
** as the second argument to the virtual table method invoked.
**
** If op is SAVEPOINT_BEGIN, the xSavepoint method is invoked. If it is
** SAVEPOINT_ROLLBACK, the xRollbackTo method. Otherwise, if op is
** SAVEPOINT_RELEASE, then the xRelease method of each virtual table with
** an open transaction is invoked.
**
** If any virtual table method returns an error code other than SQLITE_OK,
** processing is abandoned and the error returned to the caller of this
** function immediately. If all calls to virtual table methods are successful,
** SQLITE_OK is returned.
*/
SQLITE_PRIVATE int sqlite3VtabSavepoint(sqlite3 *db, int op, int iSavepoint){
int rc = SQLITE_OK;
assert( op==SAVEPOINT_RELEASE||op==SAVEPOINT_ROLLBACK||op==SAVEPOINT_BEGIN );
assert( iSavepoint>=-1 );
if( db->aVTrans ){
int i;
for(i=0; rc==SQLITE_OK && i<db->nVTrans; i++){
VTable *pVTab = db->aVTrans[i];
const sqlite3_module *pMod = pVTab->pMod->pModule;
if( pVTab->pVtab && pMod->iVersion>=2 ){
int (*xMethod)(sqlite3_vtab *, int);
sqlite3VtabLock(pVTab);
switch( op ){
case SAVEPOINT_BEGIN:
xMethod = pMod->xSavepoint;
pVTab->iSavepoint = iSavepoint+1;
break;
case SAVEPOINT_ROLLBACK:
xMethod = pMod->xRollbackTo;
break;
default:
xMethod = pMod->xRelease;
break;
}
if( xMethod && pVTab->iSavepoint>iSavepoint ){
rc = xMethod(pVTab->pVtab, iSavepoint);
}
sqlite3VtabUnlock(pVTab);
}
}
}
return rc;
}
/*
** The first parameter (pDef) is a function implementation. The
** second parameter (pExpr) is the first argument to this function.
** If pExpr is a column in a virtual table, then let the virtual
** table implementation have an opportunity to overload the function.
**
** This routine is used to allow virtual table implementations to
** overload MATCH, LIKE, GLOB, and REGEXP operators.
**
** Return either the pDef argument (indicating no change) or a
** new FuncDef structure that is marked as ephemeral using the
** SQLITE_FUNC_EPHEM flag.
*/
SQLITE_PRIVATE FuncDef *sqlite3VtabOverloadFunction(
sqlite3 *db, /* Database connection for reporting malloc problems */
FuncDef *pDef, /* Function to possibly overload */
int nArg, /* Number of arguments to the function */
Expr *pExpr /* First argument to the function */
){
Table *pTab;
sqlite3_vtab *pVtab;
sqlite3_module *pMod;
void (*xSFunc)(sqlite3_context*,int,sqlite3_value**) = 0;
void *pArg = 0;
FuncDef *pNew;
int rc = 0;
/* Check to see the left operand is a column in a virtual table */
if( NEVER(pExpr==0) ) return pDef;
if( pExpr->op!=TK_COLUMN ) return pDef;
pTab = pExpr->y.pTab;
if( pTab==0 ) return pDef;
if( !IsVirtual(pTab) ) return pDef;
pVtab = sqlite3GetVTable(db, pTab)->pVtab;
assert( pVtab!=0 );
assert( pVtab->pModule!=0 );
pMod = (sqlite3_module *)pVtab->pModule;
if( pMod->xFindFunction==0 ) return pDef;
/* Call the xFindFunction method on the virtual table implementation
** to see if the implementation wants to overload this function.
**
** Though undocumented, we have historically always invoked xFindFunction
** with an all lower-case function name. Continue in this tradition to
** avoid any chance of an incompatibility.
*/
#ifdef SQLITE_DEBUG
{
int i;
for(i=0; pDef->zName[i]; i++){
unsigned char x = (unsigned char)pDef->zName[i];
assert( x==sqlite3UpperToLower[x] );
}
}
#endif
rc = pMod->xFindFunction(pVtab, nArg, pDef->zName, &xSFunc, &pArg);
if( rc==0 ){
return pDef;
}
/* Create a new ephemeral function definition for the overloaded
** function */
pNew = sqlite3DbMallocZero(db, sizeof(*pNew)
+ sqlite3Strlen30(pDef->zName) + 1);
if( pNew==0 ){
return pDef;
}
*pNew = *pDef;
pNew->zName = (const char*)&pNew[1];
memcpy((char*)&pNew[1], pDef->zName, sqlite3Strlen30(pDef->zName)+1);
pNew->xSFunc = xSFunc;
pNew->pUserData = pArg;
pNew->funcFlags |= SQLITE_FUNC_EPHEM;
return pNew;
}
/*
** Make sure virtual table pTab is contained in the pParse->apVirtualLock[]
** array so that an OP_VBegin will get generated for it. Add pTab to the
** array if it is missing. If pTab is already in the array, this routine
** is a no-op.
*/
SQLITE_PRIVATE void sqlite3VtabMakeWritable(Parse *pParse, Table *pTab){
Parse *pToplevel = sqlite3ParseToplevel(pParse);
int i, n;
Table **apVtabLock;
assert( IsVirtual(pTab) );
for(i=0; i<pToplevel->nVtabLock; i++){
if( pTab==pToplevel->apVtabLock[i] ) return;
}
n = (pToplevel->nVtabLock+1)*sizeof(pToplevel->apVtabLock[0]);
apVtabLock = sqlite3Realloc(pToplevel->apVtabLock, n);
if( apVtabLock ){
pToplevel->apVtabLock = apVtabLock;
pToplevel->apVtabLock[pToplevel->nVtabLock++] = pTab;
}else{
sqlite3OomFault(pToplevel->db);
}
}
/*
** Check to see if virtual table module pMod can be have an eponymous
** virtual table instance. If it can, create one if one does not already
** exist. Return non-zero if the eponymous virtual table instance exists
** when this routine returns, and return zero if it does not exist.
**
** An eponymous virtual table instance is one that is named after its
** module, and more importantly, does not require a CREATE VIRTUAL TABLE
** statement in order to come into existance. Eponymous virtual table
** instances always exist. They cannot be DROP-ed.
**
** Any virtual table module for which xConnect and xCreate are the same
** method can have an eponymous virtual table instance.
*/
SQLITE_PRIVATE int sqlite3VtabEponymousTableInit(Parse *pParse, Module *pMod){
const sqlite3_module *pModule = pMod->pModule;
Table *pTab;
char *zErr = 0;
int rc;
sqlite3 *db = pParse->db;
if( pMod->pEpoTab ) return 1;
if( pModule->xCreate!=0 && pModule->xCreate!=pModule->xConnect ) return 0;
pTab = sqlite3DbMallocZero(db, sizeof(Table));
if( pTab==0 ) return 0;
pTab->zName = sqlite3DbStrDup(db, pMod->zName);
if( pTab->zName==0 ){
sqlite3DbFree(db, pTab);
return 0;
}
pMod->pEpoTab = pTab;
pTab->nTabRef = 1;
pTab->pSchema = db->aDb[0].pSchema;
assert( pTab->nModuleArg==0 );
pTab->iPKey = -1;
addModuleArgument(pParse, pTab, sqlite3DbStrDup(db, pTab->zName));
addModuleArgument(pParse, pTab, 0);
addModuleArgument(pParse, pTab, sqlite3DbStrDup(db, pTab->zName));
rc = vtabCallConstructor(db, pTab, pMod, pModule->xConnect, &zErr);
if( rc ){
sqlite3ErrorMsg(pParse, "%s", zErr);
sqlite3DbFree(db, zErr);
sqlite3VtabEponymousTableClear(db, pMod);
return 0;
}
return 1;
}
/*
** Erase the eponymous virtual table instance associated with
** virtual table module pMod, if it exists.
*/
SQLITE_PRIVATE void sqlite3VtabEponymousTableClear(sqlite3 *db, Module *pMod){
Table *pTab = pMod->pEpoTab;
if( pTab!=0 ){
/* Mark the table as Ephemeral prior to deleting it, so that the
** sqlite3DeleteTable() routine will know that it is not stored in
** the schema. */
pTab->tabFlags |= TF_Ephemeral;
sqlite3DeleteTable(db, pTab);
pMod->pEpoTab = 0;
}
}
/*
** Return the ON CONFLICT resolution mode in effect for the virtual
** table update operation currently in progress.
**
** The results of this routine are undefined unless it is called from
** within an xUpdate method.
*/
SQLITE_API int SQLITE_APICALL sqlite3_vtab_on_conflict(sqlite3 *db){
static const unsigned char aMap[] = {
SQLITE_ROLLBACK, SQLITE_ABORT, SQLITE_FAIL, SQLITE_IGNORE, SQLITE_REPLACE
};
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
assert( OE_Rollback==1 && OE_Abort==2 && OE_Fail==3 );
assert( OE_Ignore==4 && OE_Replace==5 );
assert( db->vtabOnConflict>=1 && db->vtabOnConflict<=5 );
return (int)aMap[db->vtabOnConflict-1];
}
/*
** Call from within the xCreate() or xConnect() methods to provide
** the SQLite core with additional information about the behavior
** of the virtual table being implemented.
*/
SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3 *db, int op, ...){
va_list ap;
int rc = SQLITE_OK;
VtabCtx *p;
#ifdef SQLITE_ENABLE_API_ARMOR
if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
sqlite3_mutex_enter(db->mutex);
p = db->pVtabCtx;
if( !p ){
rc = SQLITE_MISUSE_BKPT;
}else{
assert( p->pTab==0 || IsVirtual(p->pTab) );
va_start(ap, op);
switch( op ){
case SQLITE_VTAB_CONSTRAINT_SUPPORT: {
p->pVTable->bConstraint = (u8)va_arg(ap, int);
break;
}
case SQLITE_VTAB_INNOCUOUS: {
p->pVTable->eVtabRisk = SQLITE_VTABRISK_Low;
break;
}
case SQLITE_VTAB_DIRECTONLY: {
p->pVTable->eVtabRisk = SQLITE_VTABRISK_High;
break;
}
default: {
rc = SQLITE_MISUSE_BKPT;
break;
}
}
va_end(ap);
}
if( rc!=SQLITE_OK ) sqlite3Error(db, rc);
sqlite3_mutex_leave(db->mutex);
return rc;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
/************** End of vtab.c ************************************************/
/************** Begin file wherecode.c ***************************************/
/*
** 2015-06-06
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.
**
** This file was split off from where.c on 2015-06-06 in order to reduce the
** size of where.c and make it easier to edit. This file contains the routines
** that actually generate the bulk of the WHERE loop code. The original where.c
** file retains the code that does query planning and analysis.
*/
/* #include "sqliteInt.h" */
/************** Include whereInt.h in the middle of wherecode.c **************/
/************** Begin file whereInt.h ****************************************/
/*
** 2013-11-12
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains structure and macro definitions for the query
** planner logic in "where.c". These definitions are broken out into
** a separate source file for easier editing.
*/
#ifndef SQLITE_WHEREINT_H
#define SQLITE_WHEREINT_H
/*
** Trace output macros
*/
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
/***/ extern int sqlite3WhereTrace;
#endif
#if defined(SQLITE_DEBUG) \
&& (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE))
# define WHERETRACE(K,X) if(sqlite3WhereTrace&(K)) sqlite3DebugPrintf X
# define WHERETRACE_ENABLED 1
#else
# define WHERETRACE(K,X)
#endif
/* Forward references
*/
typedef struct WhereClause WhereClause;
typedef struct WhereMaskSet WhereMaskSet;
typedef struct WhereOrInfo WhereOrInfo;
typedef struct WhereAndInfo WhereAndInfo;
typedef struct WhereLevel WhereLevel;
typedef struct WhereLoop WhereLoop;
typedef struct WherePath WherePath;
typedef struct WhereTerm WhereTerm;
typedef struct WhereLoopBuilder WhereLoopBuilder;
typedef struct WhereScan WhereScan;
typedef struct WhereOrCost WhereOrCost;
typedef struct WhereOrSet WhereOrSet;
/*
** This object contains information needed to implement a single nested
** loop in WHERE clause.
**
** Contrast this object with WhereLoop. This object describes the
** implementation of the loop. WhereLoop describes the algorithm.
** This object contains a pointer to the WhereLoop algorithm as one of
** its elements.
**
** The WhereInfo object contains a single instance of this object for
** each term in the FROM clause (which is to say, for each of the
** nested loops as implemented). The order of WhereLevel objects determines
** the loop nested order, with WhereInfo.a[0] being the outer loop and
** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.
*/
struct WhereLevel {
int iLeftJoin; /* Memory cell used to implement LEFT OUTER JOIN */
int iTabCur; /* The VDBE cursor used to access the table */
int iIdxCur; /* The VDBE cursor used to access pIdx */
int addrBrk; /* Jump here to break out of the loop */
int addrNxt; /* Jump here to start the next IN combination */
int addrSkip; /* Jump here for next iteration of skip-scan */
int addrCont; /* Jump here to continue with the next loop cycle */
int addrFirst; /* First instruction of interior of the loop */
int addrBody; /* Beginning of the body of this loop */
int regBignull; /* big-null flag reg. True if a NULL-scan is needed */
int addrBignull; /* Jump here for next part of big-null scan */
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
u32 iLikeRepCntr; /* LIKE range processing counter register (times 2) */
int addrLikeRep; /* LIKE range processing address */
#endif
u8 iFrom; /* Which entry in the FROM clause */
u8 op, p3, p5; /* Opcode, P3 & P5 of the opcode that ends the loop */
int p1, p2; /* Operands of the opcode used to end the loop */
union { /* Information that depends on pWLoop->wsFlags */
struct {
int nIn; /* Number of entries in aInLoop[] */
struct InLoop {
int iCur; /* The VDBE cursor used by this IN operator */
int addrInTop; /* Top of the IN loop */
int iBase; /* Base register of multi-key index record */
int nPrefix; /* Number of prior entires in the key */
u8 eEndLoopOp; /* IN Loop terminator. OP_Next or OP_Prev */
} *aInLoop; /* Information about each nested IN operator */
} in; /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
Index *pCovidx; /* Possible covering index for WHERE_MULTI_OR */
} u;
struct WhereLoop *pWLoop; /* The selected WhereLoop object */
Bitmask notReady; /* FROM entries not usable at this level */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
int addrVisit; /* Address at which row is visited */
#endif
};
/*
** Each instance of this object represents an algorithm for evaluating one
** term of a join. Every term of the FROM clause will have at least
** one corresponding WhereLoop object (unless INDEXED BY constraints
** prevent a query solution - which is an error) and many terms of the
** FROM clause will have multiple WhereLoop objects, each describing a
** potential way of implementing that FROM-clause term, together with
** dependencies and cost estimates for using the chosen algorithm.
**
** Query planning consists of building up a collection of these WhereLoop
** objects, then computing a particular sequence of WhereLoop objects, with
** one WhereLoop object per FROM clause term, that satisfy all dependencies
** and that minimize the overall cost.
*/
struct WhereLoop {
Bitmask prereq; /* Bitmask of other loops that must run first */
Bitmask maskSelf; /* Bitmask identifying table iTab */
#ifdef SQLITE_DEBUG
char cId; /* Symbolic ID of this loop for debugging use */
#endif
u8 iTab; /* Position in FROM clause of table for this loop */
u8 iSortIdx; /* Sorting index number. 0==None */
LogEst rSetup; /* One-time setup cost (ex: create transient index) */
LogEst rRun; /* Cost of running each loop */
LogEst nOut; /* Estimated number of output rows */
union {
struct { /* Information for internal btree tables */
u16 nEq; /* Number of equality constraints */
u16 nBtm; /* Size of BTM vector */
u16 nTop; /* Size of TOP vector */
u16 nDistinctCol; /* Index columns used to sort for DISTINCT */
Index *pIndex; /* Index used, or NULL */
} btree;
struct { /* Information for virtual tables */
int idxNum; /* Index number */
u8 needFree; /* True if sqlite3_free(idxStr) is needed */
i8 isOrdered; /* True if satisfies ORDER BY */
u16 omitMask; /* Terms that may be omitted */
char *idxStr; /* Index identifier string */
} vtab;
} u;
u32 wsFlags; /* WHERE_* flags describing the plan */
u16 nLTerm; /* Number of entries in aLTerm[] */
u16 nSkip; /* Number of NULL aLTerm[] entries */
/**** whereLoopXfer() copies fields above ***********************/
# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
u16 nLSlot; /* Number of slots allocated for aLTerm[] */
WhereTerm **aLTerm; /* WhereTerms used */
WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
WhereTerm *aLTermSpace[3]; /* Initial aLTerm[] space */
};
/* This object holds the prerequisites and the cost of running a
** subquery on one operand of an OR operator in the WHERE clause.
** See WhereOrSet for additional information
*/
struct WhereOrCost {
Bitmask prereq; /* Prerequisites */
LogEst rRun; /* Cost of running this subquery */
LogEst nOut; /* Number of outputs for this subquery */
};
/* The WhereOrSet object holds a set of possible WhereOrCosts that
** correspond to the subquery(s) of OR-clause processing. Only the
** best N_OR_COST elements are retained.
*/
#define N_OR_COST 3
struct WhereOrSet {
u16 n; /* Number of valid a[] entries */
WhereOrCost a[N_OR_COST]; /* Set of best costs */
};
/*
** Each instance of this object holds a sequence of WhereLoop objects
** that implement some or all of a query plan.
**
** Think of each WhereLoop object as a node in a graph with arcs
** showing dependencies and costs for travelling between nodes. (That is
** not a completely accurate description because WhereLoop costs are a
** vector, not a scalar, and because dependencies are many-to-one, not
** one-to-one as are graph nodes. But it is a useful visualization aid.)
** Then a WherePath object is a path through the graph that visits some
** or all of the WhereLoop objects once.
**
** The "solver" works by creating the N best WherePath objects of length
** 1. Then using those as a basis to compute the N best WherePath objects
** of length 2. And so forth until the length of WherePaths equals the
** number of nodes in the FROM clause. The best (lowest cost) WherePath
** at the end is the chosen query plan.
*/
struct WherePath {
Bitmask maskLoop; /* Bitmask of all WhereLoop objects in this path */
Bitmask revLoop; /* aLoop[]s that should be reversed for ORDER BY */
LogEst nRow; /* Estimated number of rows generated by this path */
LogEst rCost; /* Total cost of this path */
LogEst rUnsorted; /* Total cost of this path ignoring sorting costs */
i8 isOrdered; /* No. of ORDER BY terms satisfied. -1 for unknown */
WhereLoop **aLoop; /* Array of WhereLoop objects implementing this path */
};
/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause. Each WHERE
** clause subexpression is separated from the others by AND operators,
** usually, or sometimes subexpressions separated by OR.
**
** All WhereTerms are collected into a single WhereClause structure.
** The following identity holds:
**
** WhereTerm.pWC->a[WhereTerm.idx] == WhereTerm
**
** When a term is of the form:
**
** X <op> <expr>
**
** where X is a column name and <op> is one of certain operators,
** then WhereTerm.leftCursor and WhereTerm.u.leftColumn record the
** cursor number and column number for X. WhereTerm.eOperator records
** the <op> using a bitmask encoding defined by WO_xxx below. The
** use of a bitmask encoding for the operator allows us to search
** quickly for terms that match any of several different operators.
**
** A WhereTerm might also be two or more subterms connected by OR:
**
** (t1.X <op> <expr>) OR (t1.Y <op> <expr>) OR ....
**
** In this second case, wtFlag has the TERM_ORINFO bit set and eOperator==WO_OR
** and the WhereTerm.u.pOrInfo field points to auxiliary information that
** is collected about the OR clause.
**
** If a term in the WHERE clause does not match either of the two previous
** categories, then eOperator==0. The WhereTerm.pExpr field is still set
** to the original subexpression content and wtFlags is set up appropriately
** but no other fields in the WhereTerm object are meaningful.
**
** When eOperator!=0, prereqRight and prereqAll record sets of cursor numbers,
** but they do so indirectly. A single WhereMaskSet structure translates
** cursor number into bits and the translated bit is stored in the prereq
** fields. The translation is used in order to maximize the number of
** bits that will fit in a Bitmask. The VDBE cursor numbers might be
** spread out over the non-negative integers. For example, the cursor
** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45. The WhereMaskSet
** translates these sparse cursor numbers into consecutive integers
** beginning with 0 in order to make the best possible use of the available
** bits in the Bitmask. So, in the example above, the cursor numbers
** would be mapped into integers 0 through 7.
**
** The number of terms in a join is limited by the number of bits
** in prereqRight and prereqAll. The default is 64 bits, hence SQLite
** is only able to process joins with 64 or fewer tables.
*/
struct WhereTerm {
Expr *pExpr; /* Pointer to the subexpression that is this term */
WhereClause *pWC; /* The clause this term is part of */
LogEst truthProb; /* Probability of truth for this expression */
u16 wtFlags; /* TERM_xxx bit flags. See below */
u16 eOperator; /* A WO_xx value describing <op> */
u8 nChild; /* Number of children that must disable us */
u8 eMatchOp; /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */
int iParent; /* Disable pWC->a[iParent] when this term disabled */
int leftCursor; /* Cursor number of X in "X <op> <expr>" */
union {
struct {
int leftColumn; /* Column number of X in "X <op> <expr>" */
int iField; /* Field in (?,?,?) IN (SELECT...) vector */
} x; /* Opcode other than OP_OR or OP_AND */
WhereOrInfo *pOrInfo; /* Extra information if (eOperator & WO_OR)!=0 */
WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */
} u;
Bitmask prereqRight; /* Bitmask of tables used by pExpr->pRight */
Bitmask prereqAll; /* Bitmask of tables referenced by pExpr */
};
/*
** Allowed values of WhereTerm.wtFlags
*/
#define TERM_DYNAMIC 0x0001 /* Need to call sqlite3ExprDelete(db, pExpr) */
#define TERM_VIRTUAL 0x0002 /* Added by the optimizer. Do not code */
#define TERM_CODED 0x0004 /* This term is already coded */
#define TERM_COPIED 0x0008 /* Has a child */
#define TERM_ORINFO 0x0010 /* Need to free the WhereTerm.u.pOrInfo object */
#define TERM_ANDINFO 0x0020 /* Need to free the WhereTerm.u.pAndInfo obj */
#define TERM_OR_OK 0x0040 /* Used during OR-clause processing */
#ifdef SQLITE_ENABLE_STAT4
# define TERM_VNULL 0x0080 /* Manufactured x>NULL or x<=NULL term */
#else
# define TERM_VNULL 0x0000 /* Disabled if not using stat4 */
#endif
#define TERM_LIKEOPT 0x0100 /* Virtual terms from the LIKE optimization */
#define TERM_LIKECOND 0x0200 /* Conditionally this LIKE operator term */
#define TERM_LIKE 0x0400 /* The original LIKE operator */
#define TERM_IS 0x0800 /* Term.pExpr is an IS operator */
#define TERM_VARSELECT 0x1000 /* Term.pExpr contains a correlated sub-query */
#define TERM_HEURTRUTH 0x2000 /* Heuristic truthProb used */
#ifdef SQLITE_ENABLE_STAT4
# define TERM_HIGHTRUTH 0x4000 /* Term excludes few rows */
#else
# define TERM_HIGHTRUTH 0 /* Only used with STAT4 */
#endif
/*
** An instance of the WhereScan object is used as an iterator for locating
** terms in the WHERE clause that are useful to the query planner.
*/
struct WhereScan {
WhereClause *pOrigWC; /* Original, innermost WhereClause */
WhereClause *pWC; /* WhereClause currently being scanned */
const char *zCollName; /* Required collating sequence, if not NULL */
Expr *pIdxExpr; /* Search for this index expression */
char idxaff; /* Must match this affinity, if zCollName!=NULL */
unsigned char nEquiv; /* Number of entries in aEquiv[] */
unsigned char iEquiv; /* Next unused slot in aEquiv[] */
u32 opMask; /* Acceptable operators */
int k; /* Resume scanning at this->pWC->a[this->k] */
int aiCur[11]; /* Cursors in the equivalence class */
i16 aiColumn[11]; /* Corresponding column number in the eq-class */
};
/*
** An instance of the following structure holds all information about a
** WHERE clause. Mostly this is a container for one or more WhereTerms.
**
** Explanation of pOuter: For a WHERE clause of the form
**
** a AND ((b AND c) OR (d AND e)) AND f
**
** There are separate WhereClause objects for the whole clause and for
** the subclauses "(b AND c)" and "(d AND e)". The pOuter field of the
** subclauses points to the WhereClause object for the whole clause.
*/
struct WhereClause {
WhereInfo *pWInfo; /* WHERE clause processing context */
WhereClause *pOuter; /* Outer conjunction */
u8 op; /* Split operator. TK_AND or TK_OR */
u8 hasOr; /* True if any a[].eOperator is WO_OR */
int nTerm; /* Number of terms */
int nSlot; /* Number of entries in a[] */
WhereTerm *a; /* Each a[] describes a term of the WHERE cluase */
#if defined(SQLITE_SMALL_STACK)
WhereTerm aStatic[1]; /* Initial static space for a[] */
#else
WhereTerm aStatic[8]; /* Initial static space for a[] */
#endif
};
/*
** A WhereTerm with eOperator==WO_OR has its u.pOrInfo pointer set to
** a dynamically allocated instance of the following structure.
*/
struct WhereOrInfo {
WhereClause wc; /* Decomposition into subterms */
Bitmask indexable; /* Bitmask of all indexable tables in the clause */
};
/*
** A WhereTerm with eOperator==WO_AND has its u.pAndInfo pointer set to
** a dynamically allocated instance of the following structure.
*/
struct WhereAndInfo {
WhereClause wc; /* The subexpression broken out */
};
/*
** An instance of the following structure keeps track of a mapping
** between VDBE cursor numbers and bits of the bitmasks in WhereTerm.
**
** The VDBE cursor numbers are small integers contained in
** SrcList_item.iCursor and Expr.iTable fields. For any given WHERE
** clause, the cursor numbers might not begin with 0 and they might
** contain gaps in the numbering sequence. But we want to make maximum
** use of the bits in our bitmasks. This structure provides a mapping
** from the sparse cursor numbers into consecutive integers beginning
** with 0.
**
** If WhereMaskSet.ix[A]==B it means that The A-th bit of a Bitmask
** corresponds VDBE cursor number B. The A-th bit of a bitmask is 1<<A.
**
** For example, if the WHERE clause expression used these VDBE
** cursors: 4, 5, 8, 29, 57, 73. Then the WhereMaskSet structure
** would map those cursor numbers into bits 0 through 5.
**
** Note that the mapping is not necessarily ordered. In the example
** above, the mapping might go like this: 4->3, 5->1, 8->2, 29->0,
** 57->5, 73->4. Or one of 719 other combinations might be used. It
** does not really matter. What is important is that sparse cursor
** numbers all get mapped into bit numbers that begin with 0 and contain
** no gaps.
*/
struct WhereMaskSet {
int bVarSelect; /* Used by sqlite3WhereExprUsage() */
int n; /* Number of assigned cursor values */
int ix[BMS]; /* Cursor assigned to each bit */
};
/*
** Initialize a WhereMaskSet object
*/
#define initMaskSet(P) (P)->n=0
/*
** This object is a convenience wrapper holding all information needed
** to construct WhereLoop objects for a particular query.
*/
struct WhereLoopBuilder {
WhereInfo *pWInfo; /* Information about this WHERE */
WhereClause *pWC; /* WHERE clause terms */
ExprList *pOrderBy; /* ORDER BY clause */
WhereLoop *pNew; /* Template WhereLoop */
WhereOrSet *pOrSet; /* Record best loops here, if not NULL */
#ifdef SQLITE_ENABLE_STAT4
UnpackedRecord *pRec; /* Probe for stat4 (if required) */
int nRecValid; /* Number of valid fields currently in pRec */
#endif
unsigned char bldFlags1; /* First set of SQLITE_BLDF_* flags */
unsigned char bldFlags2; /* Second set of SQLITE_BLDF_* flags */
unsigned int iPlanLimit; /* Search limiter */
};
/* Allowed values for WhereLoopBuider.bldFlags */
#define SQLITE_BLDF1_INDEXED 0x0001 /* An index is used */
#define SQLITE_BLDF1_UNIQUE 0x0002 /* All keys of a UNIQUE index used */
#define SQLITE_BLDF2_2NDPASS 0x0004 /* Second builder pass needed */
/* The WhereLoopBuilder.iPlanLimit is used to limit the number of
** index+constraint combinations the query planner will consider for a
** particular query. If this parameter is unlimited, then certain
** pathological queries can spend excess time in the sqlite3WhereBegin()
** routine. The limit is high enough that is should not impact real-world
** queries.
**
** SQLITE_QUERY_PLANNER_LIMIT is the baseline limit. The limit is
** increased by SQLITE_QUERY_PLANNER_LIMIT_INCR before each term of the FROM
** clause is processed, so that every table in a join is guaranteed to be
** able to propose a some index+constraint combinations even if the initial
** baseline limit was exhausted by prior tables of the join.
*/
#ifndef SQLITE_QUERY_PLANNER_LIMIT
# define SQLITE_QUERY_PLANNER_LIMIT 20000
#endif
#ifndef SQLITE_QUERY_PLANNER_LIMIT_INCR
# define SQLITE_QUERY_PLANNER_LIMIT_INCR 1000
#endif
/*
** Each instance of this object records a change to a single node
** in an expression tree to cause that node to point to a column
** of an index rather than an expression or a virtual column. All
** such transformations need to be undone at the end of WHERE clause
** processing.
*/
typedef struct WhereExprMod WhereExprMod;
struct WhereExprMod {
WhereExprMod *pNext; /* Next translation on a list of them all */
Expr *pExpr; /* The Expr node that was transformed */
Expr orig; /* Original value of the Expr node */
};
/*
** The WHERE clause processing routine has two halves. The
** first part does the start of the WHERE loop and the second
** half does the tail of the WHERE loop. An instance of
** this structure is returned by the first half and passed
** into the second half to give some continuity.
**
** An instance of this object holds the complete state of the query
** planner.
*/
struct WhereInfo {
Parse *pParse; /* Parsing and code generating context */
SrcList *pTabList; /* List of tables in the join */
ExprList *pOrderBy; /* The ORDER BY clause or NULL */
ExprList *pResultSet; /* Result set of the query */
Expr *pWhere; /* The complete WHERE clause */
int aiCurOnePass[2]; /* OP_OpenWrite cursors for the ONEPASS opt */
int iContinue; /* Jump here to continue with next record */
int iBreak; /* Jump here to break out of the loop */
int savedNQueryLoop; /* pParse->nQueryLoop outside the WHERE loop */
u16 wctrlFlags; /* Flags originally passed to sqlite3WhereBegin() */
LogEst iLimit; /* LIMIT if wctrlFlags has WHERE_USE_LIMIT */
u8 nLevel; /* Number of nested loop */
i8 nOBSat; /* Number of ORDER BY terms satisfied by indices */
u8 eOnePass; /* ONEPASS_OFF, or _SINGLE, or _MULTI */
u8 eDistinct; /* One of the WHERE_DISTINCT_* values */
unsigned bDeferredSeek :1; /* Uses OP_DeferredSeek */
unsigned untestedTerms :1; /* Not all WHERE terms resolved by outer loop */
unsigned bOrderedInnerLoop:1;/* True if only the inner-most loop is ordered */
unsigned sorted :1; /* True if really sorted (not just grouped) */
LogEst nRowOut; /* Estimated number of output rows */
int iTop; /* The very beginning of the WHERE loop */
int iEndWhere; /* End of the WHERE clause itself */
WhereLoop *pLoops; /* List of all WhereLoop objects */
WhereExprMod *pExprMods; /* Expression modifications */
Bitmask revMask; /* Mask of ORDER BY terms that need reversing */
WhereClause sWC; /* Decomposition of the WHERE clause */
WhereMaskSet sMaskSet; /* Map cursor numbers to bitmasks */
WhereLevel a[1]; /* Information about each nest loop in WHERE */
};
/*
** Private interfaces - callable only by other where.c routines.
**
** where.c:
*/
SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet*,int);
#ifdef WHERETRACE_ENABLED
SQLITE_PRIVATE void sqlite3WhereClausePrint(WhereClause *pWC);
SQLITE_PRIVATE void sqlite3WhereTermPrint(WhereTerm *pTerm, int iTerm);
SQLITE_PRIVATE void sqlite3WhereLoopPrint(WhereLoop *p, WhereClause *pWC);
#endif
SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(
WhereClause *pWC, /* The WHERE clause to be searched */
int iCur, /* Cursor number of LHS */
int iColumn, /* Column number of LHS */
Bitmask notReady, /* RHS must not overlap with this mask */
u32 op, /* Mask of WO_xx values describing operator */
Index *pIdx /* Must be compatible with this index, if not NULL */
);
/* wherecode.c: */
#ifndef SQLITE_OMIT_EXPLAIN
SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
Parse *pParse, /* Parse context */
SrcList *pTabList, /* Table list this loop refers to */
WhereLevel *pLevel, /* Scan to write OP_Explain opcode for */
u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */
);
#else
# define sqlite3WhereExplainOneScan(u,v,w,x) 0
#endif /* SQLITE_OMIT_EXPLAIN */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
Vdbe *v, /* Vdbe to add scanstatus entry to */
SrcList *pSrclist, /* FROM clause pLvl reads data from */
WhereLevel *pLvl, /* Level to add scanstatus() entry for */
int addrExplain /* Address of OP_Explain (or 0) */
);
#else
# define sqlite3WhereAddScanStatus(a, b, c, d) ((void)d)
#endif
SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
Parse *pParse, /* Parsing context */
Vdbe *v, /* Prepared statement under construction */
WhereInfo *pWInfo, /* Complete information about the WHERE clause */
int iLevel, /* Which level of pWInfo->a[] should be coded */
WhereLevel *pLevel, /* The current level pointer */
Bitmask notReady /* Which tables are currently available */
);
/* whereexpr.c: */
SQLITE_PRIVATE void sqlite3WhereClauseInit(WhereClause*,WhereInfo*);
SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause*);
SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause*,Expr*,u8);
SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*);
SQLITE_PRIVATE Bitmask sqlite3WhereExprUsageNN(WhereMaskSet*, Expr*);
SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*);
SQLITE_PRIVATE void sqlite3WhereExprAnalyze(SrcList*, WhereClause*);
SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(Parse*, struct SrcList_item*, WhereClause*);
/*
** Bitmasks for the operators on WhereTerm objects. These are all
** operators that are of interest to the query planner. An
** OR-ed combination of these values can be used when searching for
** particular WhereTerms within a WhereClause.
**
** Value constraints:
** WO_EQ == SQLITE_INDEX_CONSTRAINT_EQ
** WO_LT == SQLITE_INDEX_CONSTRAINT_LT
** WO_LE == SQLITE_INDEX_CONSTRAINT_LE
** WO_GT == SQLITE_INDEX_CONSTRAINT_GT
** WO_GE == SQLITE_INDEX_CONSTRAINT_GE
*/
#define WO_IN 0x0001
#define WO_EQ 0x0002
#define WO_LT (WO_EQ<<(TK_LT-TK_EQ))
#define WO_LE (WO_EQ<<(TK_LE-TK_EQ))
#define WO_GT (WO_EQ<<(TK_GT-TK_EQ))
#define WO_GE (WO_EQ<<(TK_GE-TK_EQ))
#define WO_AUX 0x0040 /* Op useful to virtual tables only */
#define WO_IS 0x0080
#define WO_ISNULL 0x0100
#define WO_OR 0x0200 /* Two or more OR-connected terms */
#define WO_AND 0x0400 /* Two or more AND-connected terms */
#define WO_EQUIV 0x0800 /* Of the form A==B, both columns */
#define WO_NOOP 0x1000 /* This term does not restrict search space */
#define WO_ALL 0x1fff /* Mask of all possible WO_* values */
#define WO_SINGLE 0x01ff /* Mask of all non-compound WO_* values */
/*
** These are definitions of bits in the WhereLoop.wsFlags field.
** The particular combination of bits in each WhereLoop help to
** determine the algorithm that WhereLoop represents.
*/
#define WHERE_COLUMN_EQ 0x00000001 /* x=EXPR */
#define WHERE_COLUMN_RANGE 0x00000002 /* x<EXPR and/or x>EXPR */
#define WHERE_COLUMN_IN 0x00000004 /* x IN (...) */
#define WHERE_COLUMN_NULL 0x00000008 /* x IS NULL */
#define WHERE_CONSTRAINT 0x0000000f /* Any of the WHERE_COLUMN_xxx values */
#define WHERE_TOP_LIMIT 0x00000010 /* x<EXPR or x<=EXPR constraint */
#define WHERE_BTM_LIMIT 0x00000020 /* x>EXPR or x>=EXPR constraint */
#define WHERE_BOTH_LIMIT 0x00000030 /* Both x>EXPR and x<EXPR */
#define WHERE_IDX_ONLY 0x00000040 /* Use index only - omit table */
#define WHERE_IPK 0x00000100 /* x is the INTEGER PRIMARY KEY */
#define WHERE_INDEXED 0x00000200 /* WhereLoop.u.btree.pIndex is valid */
#define WHERE_VIRTUALTABLE 0x00000400 /* WhereLoop.u.vtab is valid */
#define WHERE_IN_ABLE 0x00000800 /* Able to support an IN operator */
#define WHERE_ONEROW 0x00001000 /* Selects no more than one row */
#define WHERE_MULTI_OR 0x00002000 /* OR using multiple indices */
#define WHERE_AUTO_INDEX 0x00004000 /* Uses an ephemeral index */
#define WHERE_SKIPSCAN 0x00008000 /* Uses the skip-scan algorithm */
#define WHERE_UNQ_WANTED 0x00010000 /* WHERE_ONEROW would have been helpful*/
#define WHERE_PARTIALIDX 0x00020000 /* The automatic index is partial */
#define WHERE_IN_EARLYOUT 0x00040000 /* Perhaps quit IN loops early */
#define WHERE_BIGNULL_SORT 0x00080000 /* Column nEq of index is BIGNULL */
#define WHERE_IN_SEEKSCAN 0x00100000 /* Seek-scan optimization for IN */
#endif /* !defined(SQLITE_WHEREINT_H) */
/************** End of whereInt.h ********************************************/
/************** Continuing where we left off in wherecode.c ******************/
#ifndef SQLITE_OMIT_EXPLAIN
/*
** Return the name of the i-th column of the pIdx index.
*/
static const char *explainIndexColumnName(Index *pIdx, int i){
i = pIdx->aiColumn[i];
if( i==XN_EXPR ) return "<expr>";
if( i==XN_ROWID ) return "rowid";
return pIdx->pTable->aCol[i].zName;
}
/*
** This routine is a helper for explainIndexRange() below
**
** pStr holds the text of an expression that we are building up one term
** at a time. This routine adds a new term to the end of the expression.
** Terms are separated by AND so add the "AND" text for second and subsequent
** terms only.
*/
static void explainAppendTerm(
StrAccum *pStr, /* The text expression being built */
Index *pIdx, /* Index to read column names from */
int nTerm, /* Number of terms */
int iTerm, /* Zero-based index of first term. */
int bAnd, /* Non-zero to append " AND " */
const char *zOp /* Name of the operator */
){
int i;
assert( nTerm>=1 );
if( bAnd ) sqlite3_str_append(pStr, " AND ", 5);
if( nTerm>1 ) sqlite3_str_append(pStr, "(", 1);
for(i=0; i<nTerm; i++){
if( i ) sqlite3_str_append(pStr, ",", 1);
sqlite3_str_appendall(pStr, explainIndexColumnName(pIdx, iTerm+i));
}
if( nTerm>1 ) sqlite3_str_append(pStr, ")", 1);
sqlite3_str_append(pStr, zOp, 1);
if( nTerm>1 ) sqlite3_str_append(pStr, "(", 1);
for(i=0; i<nTerm; i++){
if( i ) sqlite3_str_append(pStr, ",", 1);
sqlite3_str_append(pStr, "?", 1);
}
if( nTerm>1 ) sqlite3_str_append(pStr, ")", 1);
}
/*
** Argument pLevel describes a strategy for scanning table pTab. This
** function appends text to pStr that describes the subset of table
** rows scanned by the strategy in the form of an SQL expression.
**
** For example, if the query:
**
** SELECT * FROM t1 WHERE a=1 AND b>2;
**
** is run and there is an index on (a, b), then this function returns a
** string similar to:
**
** "a=? AND b>?"
*/
static void explainIndexRange(StrAccum *pStr, WhereLoop *pLoop){
Index *pIndex = pLoop->u.btree.pIndex;
u16 nEq = pLoop->u.btree.nEq;
u16 nSkip = pLoop->nSkip;
int i, j;
if( nEq==0 && (pLoop->wsFlags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ) return;
sqlite3_str_append(pStr, " (", 2);
for(i=0; i<nEq; i++){
const char *z = explainIndexColumnName(pIndex, i);
if( i ) sqlite3_str_append(pStr, " AND ", 5);
sqlite3_str_appendf(pStr, i>=nSkip ? "%s=?" : "ANY(%s)", z);
}
j = i;
if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
explainAppendTerm(pStr, pIndex, pLoop->u.btree.nBtm, j, i, ">");
i = 1;
}
if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
explainAppendTerm(pStr, pIndex, pLoop->u.btree.nTop, j, i, "<");
}
sqlite3_str_append(pStr, ")", 1);
}
/*
** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN
** command, or if either SQLITE_DEBUG or SQLITE_ENABLE_STMT_SCANSTATUS was
** defined at compile-time. If it is not a no-op, a single OP_Explain opcode
** is added to the output to describe the table scan strategy in pLevel.
**
** If an OP_Explain opcode is added to the VM, its address is returned.
** Otherwise, if no OP_Explain is coded, zero is returned.
*/
SQLITE_PRIVATE int sqlite3WhereExplainOneScan(
Parse *pParse, /* Parse context */
SrcList *pTabList, /* Table list this loop refers to */
WhereLevel *pLevel, /* Scan to write OP_Explain opcode for */
u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */
){
int ret = 0;
#if !defined(SQLITE_DEBUG) && !defined(SQLITE_ENABLE_STMT_SCANSTATUS)
if( sqlite3ParseToplevel(pParse)->explain==2 )
#endif
{
struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
Vdbe *v = pParse->pVdbe; /* VM being constructed */
sqlite3 *db = pParse->db; /* Database handle */
int isSearch; /* True for a SEARCH. False for SCAN. */
WhereLoop *pLoop; /* The controlling WhereLoop object */
u32 flags; /* Flags that describe this loop */
char *zMsg; /* Text to add to EQP output */
StrAccum str; /* EQP output string */
char zBuf[100]; /* Initial space for EQP output string */
pLoop = pLevel->pWLoop;
flags = pLoop->wsFlags;
if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_OR_SUBCLAUSE) ) return 0;
isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
|| ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
|| (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
sqlite3StrAccumInit(&str, db, zBuf, sizeof(zBuf), SQLITE_MAX_LENGTH);
sqlite3_str_appendall(&str, isSearch ? "SEARCH" : "SCAN");
if( pItem->pSelect ){
sqlite3_str_appendf(&str, " SUBQUERY %u", pItem->pSelect->selId);
}else{
sqlite3_str_appendf(&str, " TABLE %s", pItem->zName);
}
if( pItem->zAlias ){
sqlite3_str_appendf(&str, " AS %s", pItem->zAlias);
}
if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 ){
const char *zFmt = 0;
Index *pIdx;
assert( pLoop->u.btree.pIndex!=0 );
pIdx = pLoop->u.btree.pIndex;
assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) );
if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){
if( isSearch ){
zFmt = "PRIMARY KEY";
}
}else if( flags & WHERE_PARTIALIDX ){
zFmt = "AUTOMATIC PARTIAL COVERING INDEX";
}else if( flags & WHERE_AUTO_INDEX ){
zFmt = "AUTOMATIC COVERING INDEX";
}else if( flags & WHERE_IDX_ONLY ){
zFmt = "COVERING INDEX %s";
}else{
zFmt = "INDEX %s";
}
if( zFmt ){
sqlite3_str_append(&str, " USING ", 7);
sqlite3_str_appendf(&str, zFmt, pIdx->zName);
explainIndexRange(&str, pLoop);
}
}else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
const char *zRangeOp;
if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
zRangeOp = "=";
}else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
zRangeOp = ">? AND rowid<";
}else if( flags&WHERE_BTM_LIMIT ){
zRangeOp = ">";
}else{
assert( flags&WHERE_TOP_LIMIT);
zRangeOp = "<";
}
sqlite3_str_appendf(&str,
" USING INTEGER PRIMARY KEY (rowid%s?)",zRangeOp);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
sqlite3_str_appendf(&str, " VIRTUAL TABLE INDEX %d:%s",
pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
}
#endif
#ifdef SQLITE_EXPLAIN_ESTIMATED_ROWS
if( pLoop->nOut>=10 ){
sqlite3_str_appendf(&str, " (~%llu rows)",
sqlite3LogEstToInt(pLoop->nOut));
}else{
sqlite3_str_append(&str, " (~1 row)", 9);
}
#endif
zMsg = sqlite3StrAccumFinish(&str);
sqlite3ExplainBreakpoint("",zMsg);
ret = sqlite3VdbeAddOp4(v, OP_Explain, sqlite3VdbeCurrentAddr(v),
pParse->addrExplain, 0, zMsg,P4_DYNAMIC);
}
return ret;
}
#endif /* SQLITE_OMIT_EXPLAIN */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
/*
** Configure the VM passed as the first argument with an
** sqlite3_stmt_scanstatus() entry corresponding to the scan used to
** implement level pLvl. Argument pSrclist is a pointer to the FROM
** clause that the scan reads data from.
**
** If argument addrExplain is not 0, it must be the address of an
** OP_Explain instruction that describes the same loop.
*/
SQLITE_PRIVATE void sqlite3WhereAddScanStatus(
Vdbe *v, /* Vdbe to add scanstatus entry to */
SrcList *pSrclist, /* FROM clause pLvl reads data from */
WhereLevel *pLvl, /* Level to add scanstatus() entry for */
int addrExplain /* Address of OP_Explain (or 0) */
){
const char *zObj = 0;
WhereLoop *pLoop = pLvl->pWLoop;
if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 && pLoop->u.btree.pIndex!=0 ){
zObj = pLoop->u.btree.pIndex->zName;
}else{
zObj = pSrclist->a[pLvl->iFrom].zName;
}
sqlite3VdbeScanStatus(
v, addrExplain, pLvl->addrBody, pLvl->addrVisit, pLoop->nOut, zObj
);
}
#endif
/*
** Disable a term in the WHERE clause. Except, do not disable the term
** if it controls a LEFT OUTER JOIN and it did not originate in the ON
** or USING clause of that join.
**
** Consider the term t2.z='ok' in the following queries:
**
** (1) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
** (2) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
** (3) SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
**
** The t2.z='ok' is disabled in the in (2) because it originates
** in the ON clause. The term is disabled in (3) because it is not part
** of a LEFT OUTER JOIN. In (1), the term is not disabled.
**
** Disabling a term causes that term to not be tested in the inner loop
** of the join. Disabling is an optimization. When terms are satisfied
** by indices, we disable them to prevent redundant tests in the inner
** loop. We would get the correct results if nothing were ever disabled,
** but joins might run a little slower. The trick is to disable as much
** as we can without disabling too much. If we disabled in (1), we'd get
** the wrong answer. See ticket #813.
**
** If all the children of a term are disabled, then that term is also
** automatically disabled. In this way, terms get disabled if derived
** virtual terms are tested first. For example:
**
** x GLOB 'abc*' AND x>='abc' AND x<'acd'
** \___________/ \______/ \_____/
** parent child1 child2
**
** Only the parent term was in the original WHERE clause. The child1
** and child2 terms were added by the LIKE optimization. If both of
** the virtual child terms are valid, then testing of the parent can be
** skipped.
**
** Usually the parent term is marked as TERM_CODED. But if the parent
** term was originally TERM_LIKE, then the parent gets TERM_LIKECOND instead.
** The TERM_LIKECOND marking indicates that the term should be coded inside
** a conditional such that is only evaluated on the second pass of a
** LIKE-optimization loop, when scanning BLOBs instead of strings.
*/
static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
int nLoop = 0;
assert( pTerm!=0 );
while( (pTerm->wtFlags & TERM_CODED)==0
&& (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
&& (pLevel->notReady & pTerm->prereqAll)==0
){
if( nLoop && (pTerm->wtFlags & TERM_LIKE)!=0 ){
pTerm->wtFlags |= TERM_LIKECOND;
}else{
pTerm->wtFlags |= TERM_CODED;
}
if( pTerm->iParent<0 ) break;
pTerm = &pTerm->pWC->a[pTerm->iParent];
assert( pTerm!=0 );
pTerm->nChild--;
if( pTerm->nChild!=0 ) break;
nLoop++;
}
}
/*
** Code an OP_Affinity opcode to apply the column affinity string zAff
** to the n registers starting at base.
**
** As an optimization, SQLITE_AFF_BLOB and SQLITE_AFF_NONE entries (which
** are no-ops) at the beginning and end of zAff are ignored. If all entries
** in zAff are SQLITE_AFF_BLOB or SQLITE_AFF_NONE, then no code gets generated.
**
** This routine makes its own copy of zAff so that the caller is free
** to modify zAff after this routine returns.
*/
static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
Vdbe *v = pParse->pVdbe;
if( zAff==0 ){
assert( pParse->db->mallocFailed );
return;
}
assert( v!=0 );
/* Adjust base and n to skip over SQLITE_AFF_BLOB and SQLITE_AFF_NONE
** entries at the beginning and end of the affinity string.
*/
assert( SQLITE_AFF_NONE<SQLITE_AFF_BLOB );
while( n>0 && zAff[0]<=SQLITE_AFF_BLOB ){
n--;
base++;
zAff++;
}
while( n>1 && zAff[n-1]<=SQLITE_AFF_BLOB ){
n--;
}
/* Code the OP_Affinity opcode if there is anything left to do. */
if( n>0 ){
sqlite3VdbeAddOp4(v, OP_Affinity, base, n, 0, zAff, n);
}
}
/*
** Expression pRight, which is the RHS of a comparison operation, is
** either a vector of n elements or, if n==1, a scalar expression.
** Before the comparison operation, affinity zAff is to be applied
** to the pRight values. This function modifies characters within the
** affinity string to SQLITE_AFF_BLOB if either:
**
** * the comparison will be performed with no affinity, or
** * the affinity change in zAff is guaranteed not to change the value.
*/
static void updateRangeAffinityStr(
Expr *pRight, /* RHS of comparison */
int n, /* Number of vector elements in comparison */
char *zAff /* Affinity string to modify */
){
int i;
for(i=0; i<n; i++){
Expr *p = sqlite3VectorFieldSubexpr(pRight, i);
if( sqlite3CompareAffinity(p, zAff[i])==SQLITE_AFF_BLOB
|| sqlite3ExprNeedsNoAffinityChange(p, zAff[i])
){
zAff[i] = SQLITE_AFF_BLOB;
}
}
}
/*
** pX is an expression of the form: (vector) IN (SELECT ...)
** In other words, it is a vector IN operator with a SELECT clause on the
** LHS. But not all terms in the vector are indexable and the terms might
** not be in the correct order for indexing.
**
** This routine makes a copy of the input pX expression and then adjusts
** the vector on the LHS with corresponding changes to the SELECT so that
** the vector contains only index terms and those terms are in the correct
** order. The modified IN expression is returned. The caller is responsible
** for deleting the returned expression.
**
** Example:
**
** CREATE TABLE t1(a,b,c,d,e,f);
** CREATE INDEX t1x1 ON t1(e,c);
** SELECT * FROM t1 WHERE (a,b,c,d,e) IN (SELECT v,w,x,y,z FROM t2)
** \_______________________________________/
** The pX expression
**
** Since only columns e and c can be used with the index, in that order,
** the modified IN expression that is returned will be:
**
** (e,c) IN (SELECT z,x FROM t2)
**
** The reduced pX is different from the original (obviously) and thus is
** only used for indexing, to improve performance. The original unaltered
** IN expression must also be run on each output row for correctness.
*/
static Expr *removeUnindexableInClauseTerms(
Parse *pParse, /* The parsing context */
int iEq, /* Look at loop terms starting here */
WhereLoop *pLoop, /* The current loop */
Expr *pX /* The IN expression to be reduced */
){
sqlite3 *db = pParse->db;
Expr *pNew;
pNew = sqlite3ExprDup(db, pX, 0);
if( db->mallocFailed==0 ){
ExprList *pOrigRhs = pNew->x.pSelect->pEList; /* Original unmodified RHS */
ExprList *pOrigLhs = pNew->pLeft->x.pList; /* Original unmodified LHS */
ExprList *pRhs = 0; /* New RHS after modifications */
ExprList *pLhs = 0; /* New LHS after mods */
int i; /* Loop counter */
Select *pSelect; /* Pointer to the SELECT on the RHS */
for(i=iEq; i<pLoop->nLTerm; i++){
if( pLoop->aLTerm[i]->pExpr==pX ){
int iField = pLoop->aLTerm[i]->u.x.iField - 1;
if( pOrigRhs->a[iField].pExpr==0 ) continue; /* Duplicate PK column */
pRhs = sqlite3ExprListAppend(pParse, pRhs, pOrigRhs->a[iField].pExpr);
pOrigRhs->a[iField].pExpr = 0;
assert( pOrigLhs->a[iField].pExpr!=0 );
pLhs = sqlite3ExprListAppend(pParse, pLhs, pOrigLhs->a[iField].pExpr);
pOrigLhs->a[iField].pExpr = 0;
}
}
sqlite3ExprListDelete(db, pOrigRhs);
sqlite3ExprListDelete(db, pOrigLhs);
pNew->pLeft->x.pList = pLhs;
pNew->x.pSelect->pEList = pRhs;
if( pLhs && pLhs->nExpr==1 ){
/* Take care here not to generate a TK_VECTOR containing only a
** single value. Since the parser never creates such a vector, some
** of the subroutines do not handle this case. */
Expr *p = pLhs->a[0].pExpr;
pLhs->a[0].pExpr = 0;
sqlite3ExprDelete(db, pNew->pLeft);
pNew->pLeft = p;
}
pSelect = pNew->x.pSelect;
if( pSelect->pOrderBy ){
/* If the SELECT statement has an ORDER BY clause, zero the
** iOrderByCol variables. These are set to non-zero when an
** ORDER BY term exactly matches one of the terms of the
** result-set. Since the result-set of the SELECT statement may
** have been modified or reordered, these variables are no longer
** set correctly. Since setting them is just an optimization,
** it's easiest just to zero them here. */
ExprList *pOrderBy = pSelect->pOrderBy;
for(i=0; i<pOrderBy->nExpr; i++){
pOrderBy->a[i].u.x.iOrderByCol = 0;
}
}
#if 0
printf("For indexing, change the IN expr:\n");
sqlite3TreeViewExpr(0, pX, 0);
printf("Into:\n");
sqlite3TreeViewExpr(0, pNew, 0);
#endif
}
return pNew;
}
/*
** Generate code for a single equality term of the WHERE clause. An equality
** term can be either X=expr or X IN (...). pTerm is the term to be
** coded.
**
** The current value for the constraint is left in a register, the index
** of which is returned. An attempt is made store the result in iTarget but
** this is only guaranteed for TK_ISNULL and TK_IN constraints. If the
** constraint is a TK_EQ or TK_IS, then the current value might be left in
** some other register and it is the caller's responsibility to compensate.
**
** For a constraint of the form X=expr, the expression is evaluated in
** straight-line code. For constraints of the form X IN (...)
** this routine sets up a loop that will iterate over all values of X.
*/
static int codeEqualityTerm(
Parse *pParse, /* The parsing context */
WhereTerm *pTerm, /* The term of the WHERE clause to be coded */
WhereLevel *pLevel, /* The level of the FROM clause we are working on */
int iEq, /* Index of the equality term within this level */
int bRev, /* True for reverse-order IN operations */
int iTarget /* Attempt to leave results in this register */
){
Expr *pX = pTerm->pExpr;
Vdbe *v = pParse->pVdbe;
int iReg; /* Register holding results */
assert( pLevel->pWLoop->aLTerm[iEq]==pTerm );
assert( iTarget>0 );
if( pX->op==TK_EQ || pX->op==TK_IS ){
iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
}else if( pX->op==TK_ISNULL ){
iReg = iTarget;
sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
#ifndef SQLITE_OMIT_SUBQUERY
}else{
int eType = IN_INDEX_NOOP;
int iTab;
struct InLoop *pIn;
WhereLoop *pLoop = pLevel->pWLoop;
int i;
int nEq = 0;
int *aiMap = 0;
if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
&& pLoop->u.btree.pIndex!=0
&& pLoop->u.btree.pIndex->aSortOrder[iEq]
){
testcase( iEq==0 );
testcase( bRev );
bRev = !bRev;
}
assert( pX->op==TK_IN );
iReg = iTarget;
for(i=0; i<iEq; i++){
if( pLoop->aLTerm[i] && pLoop->aLTerm[i]->pExpr==pX ){
disableTerm(pLevel, pTerm);
return iTarget;
}
}
for(i=iEq;i<pLoop->nLTerm; i++){
assert( pLoop->aLTerm[i]!=0 );
if( pLoop->aLTerm[i]->pExpr==pX ) nEq++;
}
iTab = 0;
if( (pX->flags & EP_xIsSelect)==0 || pX->x.pSelect->pEList->nExpr==1 ){
eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, 0, &iTab);
}else{
sqlite3 *db = pParse->db;
pX = removeUnindexableInClauseTerms(pParse, iEq, pLoop, pX);
if( !db->mallocFailed ){
aiMap = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*nEq);
eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, aiMap, &iTab);
pTerm->pExpr->iTable = iTab;
}
sqlite3ExprDelete(db, pX);
pX = pTerm->pExpr;
}
if( eType==IN_INDEX_INDEX_DESC ){
testcase( bRev );
bRev = !bRev;
}
sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
VdbeCoverageIf(v, bRev);
VdbeCoverageIf(v, !bRev);
assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
pLoop->wsFlags |= WHERE_IN_ABLE;
if( pLevel->u.in.nIn==0 ){
pLevel->addrNxt = sqlite3VdbeMakeLabel(pParse);
}
if( iEq>0 && (pLoop->wsFlags & WHERE_IN_SEEKSCAN)==0 ){
pLoop->wsFlags |= WHERE_IN_EARLYOUT;
}
i = pLevel->u.in.nIn;
pLevel->u.in.nIn += nEq;
pLevel->u.in.aInLoop =
sqlite3DbReallocOrFree(pParse->db, pLevel->u.in.aInLoop,
sizeof(pLevel->u.in.aInLoop[0])*pLevel->u.in.nIn);
pIn = pLevel->u.in.aInLoop;
if( pIn ){
int iMap = 0; /* Index in aiMap[] */
pIn += i;
for(i=iEq;i<pLoop->nLTerm; i++){
if( pLoop->aLTerm[i]->pExpr==pX ){
int iOut = iReg + i - iEq;
if( eType==IN_INDEX_ROWID ){
pIn->addrInTop = sqlite3VdbeAddOp2(v, OP_Rowid, iTab, iOut);
}else{
int iCol = aiMap ? aiMap[iMap++] : 0;
pIn->addrInTop = sqlite3VdbeAddOp3(v,OP_Column,iTab, iCol, iOut);
}
sqlite3VdbeAddOp1(v, OP_IsNull, iOut); VdbeCoverage(v);
if( i==iEq ){
pIn->iCur = iTab;
pIn->eEndLoopOp = bRev ? OP_Prev : OP_Next;
if( iEq>0 ){
pIn->iBase = iReg - i;
pIn->nPrefix = i;
}else{
pIn->nPrefix = 0;
}
}else{
pIn->eEndLoopOp = OP_Noop;
}
pIn++;
}
}
testcase( iEq>0
&& (pLoop->wsFlags & WHERE_IN_SEEKSCAN)==0
&& (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 );
if( iEq>0
&& (pLoop->wsFlags & (WHERE_IN_SEEKSCAN|WHERE_VIRTUALTABLE))==0
){
sqlite3VdbeAddOp3(v, OP_SeekHit, pLevel->iIdxCur, 0, iEq);
}
}else{
pLevel->u.in.nIn = 0;
}
sqlite3DbFree(pParse->db, aiMap);
#endif
}
disableTerm(pLevel, pTerm);
return iReg;
}
/*
** Generate code that will evaluate all == and IN constraints for an
** index scan.
**
** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c).
** Suppose the WHERE clause is this: a==5 AND b IN (1,2,3) AND c>5 AND c<10
** The index has as many as three equality constraints, but in this
** example, the third "c" value is an inequality. So only two
** constraints are coded. This routine will generate code to evaluate
** a==5 and b IN (1,2,3). The current values for a and b will be stored
** in consecutive registers and the index of the first register is returned.
**
** In the example above nEq==2. But this subroutine works for any value
** of nEq including 0. If nEq==0, this routine is nearly a no-op.
** The only thing it does is allocate the pLevel->iMem memory cell and
** compute the affinity string.
**
** The nExtraReg parameter is 0 or 1. It is 0 if all WHERE clause constraints
** are == or IN and are covered by the nEq. nExtraReg is 1 if there is
** an inequality constraint (such as the "c>=5 AND c<10" in the example) that
** occurs after the nEq quality constraints.
**
** This routine allocates a range of nEq+nExtraReg memory cells and returns
** the index of the first memory cell in that range. The code that
** calls this routine will use that memory range to store keys for
** start and termination conditions of the loop.
** key value of the loop. If one or more IN operators appear, then
** this routine allocates an additional nEq memory cells for internal
** use.
**
** Before returning, *pzAff is set to point to a buffer containing a
** copy of the column affinity string of the index allocated using
** sqlite3DbMalloc(). Except, entries in the copy of the string associated
** with equality constraints that use BLOB or NONE affinity are set to
** SQLITE_AFF_BLOB. This is to deal with SQL such as the following:
**
** CREATE TABLE t1(a TEXT PRIMARY KEY, b);
** SELECT ... FROM t1 AS t2, t1 WHERE t1.a = t2.b;
**
** In the example above, the index on t1(a) has TEXT affinity. But since
** the right hand side of the equality constraint (t2.b) has BLOB/NONE affinity,
** no conversion should be attempted before using a t2.b value as part of
** a key to search the index. Hence the first byte in the returned affinity
** string in this example would be set to SQLITE_AFF_BLOB.
*/
static int codeAllEqualityTerms(
Parse *pParse, /* Parsing context */
WhereLevel *pLevel, /* Which nested loop of the FROM we are coding */
int bRev, /* Reverse the order of IN operators */
int nExtraReg, /* Number of extra registers to allocate */
char **pzAff /* OUT: Set to point to affinity string */
){
u16 nEq; /* The number of == or IN constraints to code */
u16 nSkip; /* Number of left-most columns to skip */
Vdbe *v = pParse->pVdbe; /* The vm under construction */
Index *pIdx; /* The index being used for this loop */
WhereTerm *pTerm; /* A single constraint term */
WhereLoop *pLoop; /* The WhereLoop object */
int j; /* Loop counter */
int regBase; /* Base register */
int nReg; /* Number of registers to allocate */
char *zAff; /* Affinity string to return */
/* This module is only called on query plans that use an index. */
pLoop = pLevel->pWLoop;
assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
nEq = pLoop->u.btree.nEq;
nSkip = pLoop->nSkip;
pIdx = pLoop->u.btree.pIndex;
assert( pIdx!=0 );
/* Figure out how many memory cells we will need then allocate them.
*/
regBase = pParse->nMem + 1;
nReg = pLoop->u.btree.nEq + nExtraReg;
pParse->nMem += nReg;
zAff = sqlite3DbStrDup(pParse->db,sqlite3IndexAffinityStr(pParse->db,pIdx));
assert( zAff!=0 || pParse->db->mallocFailed );
if( nSkip ){
int iIdxCur = pLevel->iIdxCur;
sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
VdbeCoverageIf(v, bRev==0);
VdbeCoverageIf(v, bRev!=0);
VdbeComment((v, "begin skip-scan on %s", pIdx->zName));
j = sqlite3VdbeAddOp0(v, OP_Goto);
pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT),
iIdxCur, 0, regBase, nSkip);
VdbeCoverageIf(v, bRev==0);
VdbeCoverageIf(v, bRev!=0);
sqlite3VdbeJumpHere(v, j);
for(j=0; j<nSkip; j++){
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
testcase( pIdx->aiColumn[j]==XN_EXPR );
VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));
}
}
/* Evaluate the equality constraints
*/
assert( zAff==0 || (int)strlen(zAff)>=nEq );
for(j=nSkip; j<nEq; j++){
int r1;
pTerm = pLoop->aLTerm[j];
assert( pTerm!=0 );
/* The following testcase is true for indices with redundant columns.
** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
testcase( pTerm->wtFlags & TERM_VIRTUAL );
r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
if( r1!=regBase+j ){
if( nReg==1 ){
sqlite3ReleaseTempReg(pParse, regBase);
regBase = r1;
}else{
sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
}
}
if( pTerm->eOperator & WO_IN ){
if( pTerm->pExpr->flags & EP_xIsSelect ){
/* No affinity ever needs to be (or should be) applied to a value
** from the RHS of an "? IN (SELECT ...)" expression. The
** sqlite3FindInIndex() routine has already ensured that the
** affinity of the comparison has been applied to the value. */
if( zAff ) zAff[j] = SQLITE_AFF_BLOB;
}
}else if( (pTerm->eOperator & WO_ISNULL)==0 ){
Expr *pRight = pTerm->pExpr->pRight;
if( (pTerm->wtFlags & TERM_IS)==0 && sqlite3ExprCanBeNull(pRight) ){
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
VdbeCoverage(v);
}
if( zAff ){
if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_BLOB ){
zAff[j] = SQLITE_AFF_BLOB;
}
if( sqlite3ExprNeedsNoAffinityChange(pRight, zAff[j]) ){
zAff[j] = SQLITE_AFF_BLOB;
}
}
}
}
*pzAff = zAff;
return regBase;
}
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
/*
** If the most recently coded instruction is a constant range constraint
** (a string literal) that originated from the LIKE optimization, then
** set P3 and P5 on the OP_String opcode so that the string will be cast
** to a BLOB at appropriate times.
**
** The LIKE optimization trys to evaluate "x LIKE 'abc%'" as a range
** expression: "x>='ABC' AND x<'abd'". But this requires that the range
** scan loop run twice, once for strings and a second time for BLOBs.
** The OP_String opcodes on the second pass convert the upper and lower
** bound string constants to blobs. This routine makes the necessary changes
** to the OP_String opcodes for that to happen.
**
** Except, of course, if SQLITE_LIKE_DOESNT_MATCH_BLOBS is defined, then
** only the one pass through the string space is required, so this routine
** becomes a no-op.
*/
static void whereLikeOptimizationStringFixup(
Vdbe *v, /* prepared statement under construction */
WhereLevel *pLevel, /* The loop that contains the LIKE operator */
WhereTerm *pTerm /* The upper or lower bound just coded */
){
if( pTerm->wtFlags & TERM_LIKEOPT ){
VdbeOp *pOp;
assert( pLevel->iLikeRepCntr>0 );
pOp = sqlite3VdbeGetOp(v, -1);
assert( pOp!=0 );
assert( pOp->opcode==OP_String8
|| pTerm->pWC->pWInfo->pParse->db->mallocFailed );
pOp->p3 = (int)(pLevel->iLikeRepCntr>>1); /* Register holding counter */
pOp->p5 = (u8)(pLevel->iLikeRepCntr&1); /* ASC or DESC */
}
}
#else
# define whereLikeOptimizationStringFixup(A,B,C)
#endif
#ifdef SQLITE_ENABLE_CURSOR_HINTS
/*
** Information is passed from codeCursorHint() down to individual nodes of
** the expression tree (by sqlite3WalkExpr()) using an instance of this
** structure.
*/
struct CCurHint {
int iTabCur; /* Cursor for the main table */
int iIdxCur; /* Cursor for the index, if pIdx!=0. Unused otherwise */
Index *pIdx; /* The index used to access the table */
};
/*
** This function is called for every node of an expression that is a candidate
** for a cursor hint on an index cursor. For TK_COLUMN nodes that reference
** the table CCurHint.iTabCur, verify that the same column can be
** accessed through the index. If it cannot, then set pWalker->eCode to 1.
*/
static int codeCursorHintCheckExpr(Walker *pWalker, Expr *pExpr){
struct CCurHint *pHint = pWalker->u.pCCurHint;
assert( pHint->pIdx!=0 );
if( pExpr->op==TK_COLUMN
&& pExpr->iTable==pHint->iTabCur
&& sqlite3TableColumnToIndex(pHint->pIdx, pExpr->iColumn)<0
){
pWalker->eCode = 1;
}
return WRC_Continue;
}
/*
** Test whether or not expression pExpr, which was part of a WHERE clause,
** should be included in the cursor-hint for a table that is on the rhs
** of a LEFT JOIN. Set Walker.eCode to non-zero before returning if the
** expression is not suitable.
**
** An expression is unsuitable if it might evaluate to non NULL even if
** a TK_COLUMN node that does affect the value of the expression is set
** to NULL. For example:
**
** col IS NULL
** col IS NOT NULL
** coalesce(col, 1)
** CASE WHEN col THEN 0 ELSE 1 END
*/
static int codeCursorHintIsOrFunction(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_IS
|| pExpr->op==TK_ISNULL || pExpr->op==TK_ISNOT
|| pExpr->op==TK_NOTNULL || pExpr->op==TK_CASE
){
pWalker->eCode = 1;
}else if( pExpr->op==TK_FUNCTION ){
int d1;
char d2[4];
if( 0==sqlite3IsLikeFunction(pWalker->pParse->db, pExpr, &d1, d2) ){
pWalker->eCode = 1;
}
}
return WRC_Continue;
}
/*
** This function is called on every node of an expression tree used as an
** argument to the OP_CursorHint instruction. If the node is a TK_COLUMN
** that accesses any table other than the one identified by
** CCurHint.iTabCur, then do the following:
**
** 1) allocate a register and code an OP_Column instruction to read
** the specified column into the new register, and
**
** 2) transform the expression node to a TK_REGISTER node that reads
** from the newly populated register.
**
** Also, if the node is a TK_COLUMN that does access the table idenified
** by pCCurHint.iTabCur, and an index is being used (which we will
** know because CCurHint.pIdx!=0) then transform the TK_COLUMN into
** an access of the index rather than the original table.
*/
static int codeCursorHintFixExpr(Walker *pWalker, Expr *pExpr){
int rc = WRC_Continue;
struct CCurHint *pHint = pWalker->u.pCCurHint;
if( pExpr->op==TK_COLUMN ){
if( pExpr->iTable!=pHint->iTabCur ){
int reg = ++pWalker->pParse->nMem; /* Register for column value */
sqlite3ExprCode(pWalker->pParse, pExpr, reg);
pExpr->op = TK_REGISTER;
pExpr->iTable = reg;
}else if( pHint->pIdx!=0 ){
pExpr->iTable = pHint->iIdxCur;
pExpr->iColumn = sqlite3TableColumnToIndex(pHint->pIdx, pExpr->iColumn);
assert( pExpr->iColumn>=0 );
}
}else if( pExpr->op==TK_AGG_FUNCTION ){
/* An aggregate function in the WHERE clause of a query means this must
** be a correlated sub-query, and expression pExpr is an aggregate from
** the parent context. Do not walk the function arguments in this case.
**
** todo: It should be possible to replace this node with a TK_REGISTER
** expression, as the result of the expression must be stored in a
** register at this point. The same holds for TK_AGG_COLUMN nodes. */
rc = WRC_Prune;
}
return rc;
}
/*
** Insert an OP_CursorHint instruction if it is appropriate to do so.
*/
static void codeCursorHint(
struct SrcList_item *pTabItem, /* FROM clause item */
WhereInfo *pWInfo, /* The where clause */
WhereLevel *pLevel, /* Which loop to provide hints for */
WhereTerm *pEndRange /* Hint this end-of-scan boundary term if not NULL */
){
Parse *pParse = pWInfo->pParse;
sqlite3 *db = pParse->db;
Vdbe *v = pParse->pVdbe;
Expr *pExpr = 0;
WhereLoop *pLoop = pLevel->pWLoop;
int iCur;
WhereClause *pWC;
WhereTerm *pTerm;
int i, j;
struct CCurHint sHint;
Walker sWalker;
if( OptimizationDisabled(db, SQLITE_CursorHints) ) return;
iCur = pLevel->iTabCur;
assert( iCur==pWInfo->pTabList->a[pLevel->iFrom].iCursor );
sHint.iTabCur = iCur;
sHint.iIdxCur = pLevel->iIdxCur;
sHint.pIdx = pLoop->u.btree.pIndex;
memset(&sWalker, 0, sizeof(sWalker));
sWalker.pParse = pParse;
sWalker.u.pCCurHint = &sHint;
pWC = &pWInfo->sWC;
for(i=0; i<pWC->nTerm; i++){
pTerm = &pWC->a[i];
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
if( pTerm->prereqAll & pLevel->notReady ) continue;
/* Any terms specified as part of the ON(...) clause for any LEFT
** JOIN for which the current table is not the rhs are omitted
** from the cursor-hint.
**
** If this table is the rhs of a LEFT JOIN, "IS" or "IS NULL" terms
** that were specified as part of the WHERE clause must be excluded.
** This is to address the following:
**
** SELECT ... t1 LEFT JOIN t2 ON (t1.a=t2.b) WHERE t2.c IS NULL;
**
** Say there is a single row in t2 that matches (t1.a=t2.b), but its
** t2.c values is not NULL. If the (t2.c IS NULL) constraint is
** pushed down to the cursor, this row is filtered out, causing
** SQLite to synthesize a row of NULL values. Which does match the
** WHERE clause, and so the query returns a row. Which is incorrect.
**
** For the same reason, WHERE terms such as:
**
** WHERE 1 = (t2.c IS NULL)
**
** are also excluded. See codeCursorHintIsOrFunction() for details.
*/
if( pTabItem->fg.jointype & JT_LEFT ){
Expr *pExpr = pTerm->pExpr;
if( !ExprHasProperty(pExpr, EP_FromJoin)
|| pExpr->iRightJoinTable!=pTabItem->iCursor
){
sWalker.eCode = 0;
sWalker.xExprCallback = codeCursorHintIsOrFunction;
sqlite3WalkExpr(&sWalker, pTerm->pExpr);
if( sWalker.eCode ) continue;
}
}else{
if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) continue;
}
/* All terms in pWLoop->aLTerm[] except pEndRange are used to initialize
** the cursor. These terms are not needed as hints for a pure range
** scan (that has no == terms) so omit them. */
if( pLoop->u.btree.nEq==0 && pTerm!=pEndRange ){
for(j=0; j<pLoop->nLTerm && pLoop->aLTerm[j]!=pTerm; j++){}
if( j<pLoop->nLTerm ) continue;
}
/* No subqueries or non-deterministic functions allowed */
if( sqlite3ExprContainsSubquery(pTerm->pExpr) ) continue;
/* For an index scan, make sure referenced columns are actually in
** the index. */
if( sHint.pIdx!=0 ){
sWalker.eCode = 0;
sWalker.xExprCallback = codeCursorHintCheckExpr;
sqlite3WalkExpr(&sWalker, pTerm->pExpr);
if( sWalker.eCode ) continue;
}
/* If we survive all prior tests, that means this term is worth hinting */
pExpr = sqlite3ExprAnd(pParse, pExpr, sqlite3ExprDup(db, pTerm->pExpr, 0));
}
if( pExpr!=0 ){
sWalker.xExprCallback = codeCursorHintFixExpr;
sqlite3WalkExpr(&sWalker, pExpr);
sqlite3VdbeAddOp4(v, OP_CursorHint,
(sHint.pIdx ? sHint.iIdxCur : sHint.iTabCur), 0, 0,
(const char*)pExpr, P4_EXPR);
}
}
#else
# define codeCursorHint(A,B,C,D) /* No-op */
#endif /* SQLITE_ENABLE_CURSOR_HINTS */
/*
** Cursor iCur is open on an intkey b-tree (a table). Register iRowid contains
** a rowid value just read from cursor iIdxCur, open on index pIdx. This
** function generates code to do a deferred seek of cursor iCur to the
** rowid stored in register iRowid.
**
** Normally, this is just:
**
** OP_DeferredSeek $iCur $iRowid
**
** However, if the scan currently being coded is a branch of an OR-loop and
** the statement currently being coded is a SELECT, then P3 of OP_DeferredSeek
** is set to iIdxCur and P4 is set to point to an array of integers
** containing one entry for each column of the table cursor iCur is open
** on. For each table column, if the column is the i'th column of the
** index, then the corresponding array entry is set to (i+1). If the column
** does not appear in the index at all, the array entry is set to 0.
*/
static void codeDeferredSeek(
WhereInfo *pWInfo, /* Where clause context */
Index *pIdx, /* Index scan is using */
int iCur, /* Cursor for IPK b-tree */
int iIdxCur /* Index cursor */
){
Parse *pParse = pWInfo->pParse; /* Parse context */
Vdbe *v = pParse->pVdbe; /* Vdbe to generate code within */
assert( iIdxCur>0 );
assert( pIdx->aiColumn[pIdx->nColumn-1]==-1 );
pWInfo->bDeferredSeek = 1;
sqlite3VdbeAddOp3(v, OP_DeferredSeek, iIdxCur, 0, iCur);
if( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)
&& DbMaskAllZero(sqlite3ParseToplevel(pParse)->writeMask)
){
int i;
Table *pTab = pIdx->pTable;
u32 *ai = (u32*)sqlite3DbMallocZero(pParse->db, sizeof(u32)*(pTab->nCol+1));
if( ai ){
ai[0] = pTab->nCol;
for(i=0; i<pIdx->nColumn-1; i++){
int x1, x2;
assert( pIdx->aiColumn[i]<pTab->nCol );
x1 = pIdx->aiColumn[i];
x2 = sqlite3TableColumnToStorage(pTab, x1);
testcase( x1!=x2 );
if( x1>=0 ) ai[x2+1] = i+1;
}
sqlite3VdbeChangeP4(v, -1, (char*)ai, P4_INTARRAY);
}
}
}
/*
** If the expression passed as the second argument is a vector, generate
** code to write the first nReg elements of the vector into an array
** of registers starting with iReg.
**
** If the expression is not a vector, then nReg must be passed 1. In
** this case, generate code to evaluate the expression and leave the
** result in register iReg.
*/
static void codeExprOrVector(Parse *pParse, Expr *p, int iReg, int nReg){
assert( nReg>0 );
if( p && sqlite3ExprIsVector(p) ){
#ifndef SQLITE_OMIT_SUBQUERY
if( (p->flags & EP_xIsSelect) ){
Vdbe *v = pParse->pVdbe;
int iSelect;
assert( p->op==TK_SELECT );
iSelect = sqlite3CodeSubselect(pParse, p);
sqlite3VdbeAddOp3(v, OP_Copy, iSelect, iReg, nReg-1);
}else
#endif
{
int i;
ExprList *pList = p->x.pList;
assert( nReg<=pList->nExpr );
for(i=0; i<nReg; i++){
sqlite3ExprCode(pParse, pList->a[i].pExpr, iReg+i);
}
}
}else{
assert( nReg==1 );
sqlite3ExprCode(pParse, p, iReg);
}
}
/* An instance of the IdxExprTrans object carries information about a
** mapping from an expression on table columns into a column in an index
** down through the Walker.
*/
typedef struct IdxExprTrans {
Expr *pIdxExpr; /* The index expression */
int iTabCur; /* The cursor of the corresponding table */
int iIdxCur; /* The cursor for the index */
int iIdxCol; /* The column for the index */
int iTabCol; /* The column for the table */
WhereInfo *pWInfo; /* Complete WHERE clause information */
sqlite3 *db; /* Database connection (for malloc()) */
} IdxExprTrans;
/*
** Preserve pExpr on the WhereETrans list of the WhereInfo.
*/
static void preserveExpr(IdxExprTrans *pTrans, Expr *pExpr){
WhereExprMod *pNew;
pNew = sqlite3DbMallocRaw(pTrans->db, sizeof(*pNew));
if( pNew==0 ) return;
pNew->pNext = pTrans->pWInfo->pExprMods;
pTrans->pWInfo->pExprMods = pNew;
pNew->pExpr = pExpr;
memcpy(&pNew->orig, pExpr, sizeof(*pExpr));
}
/* The walker node callback used to transform matching expressions into
** a reference to an index column for an index on an expression.
**
** If pExpr matches, then transform it into a reference to the index column
** that contains the value of pExpr.
*/
static int whereIndexExprTransNode(Walker *p, Expr *pExpr){
IdxExprTrans *pX = p->u.pIdxTrans;
if( sqlite3ExprCompare(0, pExpr, pX->pIdxExpr, pX->iTabCur)==0 ){
preserveExpr(pX, pExpr);
pExpr->affExpr = sqlite3ExprAffinity(pExpr);
pExpr->op = TK_COLUMN;
pExpr->iTable = pX->iIdxCur;
pExpr->iColumn = pX->iIdxCol;
pExpr->y.pTab = 0;
testcase( ExprHasProperty(pExpr, EP_Skip) );
testcase( ExprHasProperty(pExpr, EP_Unlikely) );
ExprClearProperty(pExpr, EP_Skip|EP_Unlikely);
return WRC_Prune;
}else{
return WRC_Continue;
}
}
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
/* A walker node callback that translates a column reference to a table
** into a corresponding column reference of an index.
*/
static int whereIndexExprTransColumn(Walker *p, Expr *pExpr){
if( pExpr->op==TK_COLUMN ){
IdxExprTrans *pX = p->u.pIdxTrans;
if( pExpr->iTable==pX->iTabCur && pExpr->iColumn==pX->iTabCol ){
assert( pExpr->y.pTab!=0 );
preserveExpr(pX, pExpr);
pExpr->affExpr = sqlite3TableColumnAffinity(pExpr->y.pTab,pExpr->iColumn);
pExpr->iTable = pX->iIdxCur;
pExpr->iColumn = pX->iIdxCol;
pExpr->y.pTab = 0;
}
}
return WRC_Continue;
}
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
/*
** For an indexes on expression X, locate every instance of expression X
** in pExpr and change that subexpression into a reference to the appropriate
** column of the index.
**
** 2019-10-24: Updated to also translate references to a VIRTUAL column in
** the table into references to the corresponding (stored) column of the
** index.
*/
static void whereIndexExprTrans(
Index *pIdx, /* The Index */
int iTabCur, /* Cursor of the table that is being indexed */
int iIdxCur, /* Cursor of the index itself */
WhereInfo *pWInfo /* Transform expressions in this WHERE clause */
){
int iIdxCol; /* Column number of the index */
ExprList *aColExpr; /* Expressions that are indexed */
Table *pTab;
Walker w;
IdxExprTrans x;
aColExpr = pIdx->aColExpr;
if( aColExpr==0 && !pIdx->bHasVCol ){
/* The index does not reference any expressions or virtual columns
** so no translations are needed. */
return;
}
pTab = pIdx->pTable;
memset(&w, 0, sizeof(w));
w.u.pIdxTrans = &x;
x.iTabCur = iTabCur;
x.iIdxCur = iIdxCur;
x.pWInfo = pWInfo;
x.db = pWInfo->pParse->db;
for(iIdxCol=0; iIdxCol<pIdx->nColumn; iIdxCol++){
i16 iRef = pIdx->aiColumn[iIdxCol];
if( iRef==XN_EXPR ){
assert( aColExpr->a[iIdxCol].pExpr!=0 );
x.pIdxExpr = aColExpr->a[iIdxCol].pExpr;
if( sqlite3ExprIsConstant(x.pIdxExpr) ) continue;
w.xExprCallback = whereIndexExprTransNode;
#ifndef SQLITE_OMIT_GENERATED_COLUMNS
}else if( iRef>=0
&& (pTab->aCol[iRef].colFlags & COLFLAG_VIRTUAL)!=0
&& (pTab->aCol[iRef].zColl==0
|| sqlite3StrICmp(pTab->aCol[iRef].zColl, sqlite3StrBINARY)==0)
){
/* Check to see if there are direct references to generated columns
** that are contained in the index. Pulling the generated column
** out of the index is an optimization only - the main table is always
** available if the index cannot be used. To avoid unnecessary
** complication, omit this optimization if the collating sequence for
** the column is non-standard */
x.iTabCol = iRef;
w.xExprCallback = whereIndexExprTransColumn;
#endif /* SQLITE_OMIT_GENERATED_COLUMNS */
}else{
continue;
}
x.iIdxCol = iIdxCol;
sqlite3WalkExpr(&w, pWInfo->pWhere);
sqlite3WalkExprList(&w, pWInfo->pOrderBy);
sqlite3WalkExprList(&w, pWInfo->pResultSet);
}
}
/*
** The pTruth expression is always true because it is the WHERE clause
** a partial index that is driving a query loop. Look through all of the
** WHERE clause terms on the query, and if any of those terms must be
** true because pTruth is true, then mark those WHERE clause terms as
** coded.
*/
static void whereApplyPartialIndexConstraints(
Expr *pTruth,
int iTabCur,
WhereClause *pWC
){
int i;
WhereTerm *pTerm;
while( pTruth->op==TK_AND ){
whereApplyPartialIndexConstraints(pTruth->pLeft, iTabCur, pWC);
pTruth = pTruth->pRight;
}
for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
Expr *pExpr;
if( pTerm->wtFlags & TERM_CODED ) continue;
pExpr = pTerm->pExpr;
if( sqlite3ExprCompare(0, pExpr, pTruth, iTabCur)==0 ){
pTerm->wtFlags |= TERM_CODED;
}
}
}
/*
** Generate code for the start of the iLevel-th loop in the WHERE clause
** implementation described by pWInfo.
*/
SQLITE_PRIVATE Bitmask sqlite3WhereCodeOneLoopStart(
Parse *pParse, /* Parsing context */
Vdbe *v, /* Prepared statement under construction */
WhereInfo *pWInfo, /* Complete information about the WHERE clause */
int iLevel, /* Which level of pWInfo->a[] should be coded */
WhereLevel *pLevel, /* The current level pointer */
Bitmask notReady /* Which tables are currently available */
){
int j, k; /* Loop counters */
int iCur; /* The VDBE cursor for the table */
int addrNxt; /* Where to jump to continue with the next IN case */
int bRev; /* True if we need to scan in reverse order */
WhereLoop *pLoop; /* The WhereLoop object being coded */
WhereClause *pWC; /* Decomposition of the entire WHERE clause */
WhereTerm *pTerm; /* A WHERE clause term */
sqlite3 *db; /* Database connection */
struct SrcList_item *pTabItem; /* FROM clause term being coded */
int addrBrk; /* Jump here to break out of the loop */
int addrHalt; /* addrBrk for the outermost loop */
int addrCont; /* Jump here to continue with next cycle */
int iRowidReg = 0; /* Rowid is stored in this register, if not zero */
int iReleaseReg = 0; /* Temp register to free before returning */
Index *pIdx = 0; /* Index used by loop (if any) */
int iLoop; /* Iteration of constraint generator loop */
pWC = &pWInfo->sWC;
db = pParse->db;
pLoop = pLevel->pWLoop;
pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
iCur = pTabItem->iCursor;
pLevel->notReady = notReady & ~sqlite3WhereGetMask(&pWInfo->sMaskSet, iCur);
bRev = (pWInfo->revMask>>iLevel)&1;
VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName));
#if WHERETRACE_ENABLED /* 0x20800 */
if( sqlite3WhereTrace & 0x800 ){
sqlite3DebugPrintf("Coding level %d of %d: notReady=%llx iFrom=%d\n",
iLevel, pWInfo->nLevel, (u64)notReady, pLevel->iFrom);
sqlite3WhereLoopPrint(pLoop, pWC);
}
if( sqlite3WhereTrace & 0x20000 ){
if( iLevel==0 ){
sqlite3DebugPrintf("WHERE clause being coded:\n");
sqlite3TreeViewExpr(0, pWInfo->pWhere, 0);
}
sqlite3DebugPrintf("All WHERE-clause terms before coding:\n");
sqlite3WhereClausePrint(pWC);
}
#endif
/* Create labels for the "break" and "continue" instructions
** for the current loop. Jump to addrBrk to break out of a loop.
** Jump to cont to go immediately to the next iteration of the
** loop.
**
** When there is an IN operator, we also have a "addrNxt" label that
** means to continue with the next IN value combination. When
** there are no IN operators in the constraints, the "addrNxt" label
** is the same as "addrBrk".
*/
addrBrk = pLevel->addrBrk = pLevel->addrNxt = sqlite3VdbeMakeLabel(pParse);
addrCont = pLevel->addrCont = sqlite3VdbeMakeLabel(pParse);
/* If this is the right table of a LEFT OUTER JOIN, allocate and
** initialize a memory cell that records if this table matches any
** row of the left table of the join.
*/
assert( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)
|| pLevel->iFrom>0 || (pTabItem[0].fg.jointype & JT_LEFT)==0
);
if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
pLevel->iLeftJoin = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
VdbeComment((v, "init LEFT JOIN no-match flag"));
}
/* Compute a safe address to jump to if we discover that the table for
** this loop is empty and can never contribute content. */
for(j=iLevel; j>0 && pWInfo->a[j].iLeftJoin==0; j--){}
addrHalt = pWInfo->a[j].addrBrk;
/* Special case of a FROM clause subquery implemented as a co-routine */
if( pTabItem->fg.viaCoroutine ){
int regYield = pTabItem->regReturn;
sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
pLevel->p2 = sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk);
VdbeCoverage(v);
VdbeComment((v, "next row of %s", pTabItem->pTab->zName));
pLevel->op = OP_Goto;
}else
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
/* Case 1: The table is a virtual-table. Use the VFilter and VNext
** to access the data.
*/
int iReg; /* P3 Value for OP_VFilter */
int addrNotFound;
int nConstraint = pLoop->nLTerm;
int iIn; /* Counter for IN constraints */
iReg = sqlite3GetTempRange(pParse, nConstraint+2);
addrNotFound = pLevel->addrBrk;
for(j=0; j<nConstraint; j++){
int iTarget = iReg+j+2;
pTerm = pLoop->aLTerm[j];
if( NEVER(pTerm==0) ) continue;
if( pTerm->eOperator & WO_IN ){
codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
addrNotFound = pLevel->addrNxt;
}else{
Expr *pRight = pTerm->pExpr->pRight;
codeExprOrVector(pParse, pRight, iTarget, 1);
}
}
sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
pLoop->u.vtab.idxStr,
pLoop->u.vtab.needFree ? P4_DYNAMIC : P4_STATIC);
VdbeCoverage(v);
pLoop->u.vtab.needFree = 0;
/* An OOM inside of AddOp4(OP_VFilter) instruction above might have freed
** the u.vtab.idxStr. NULL it out to prevent a use-after-free */
if( db->mallocFailed ) pLoop->u.vtab.idxStr = 0;
pLevel->p1 = iCur;
pLevel->op = pWInfo->eOnePass ? OP_Noop : OP_VNext;
pLevel->p2 = sqlite3VdbeCurrentAddr(v);
iIn = pLevel->u.in.nIn;
for(j=nConstraint-1; j>=0; j--){
pTerm = pLoop->aLTerm[j];
if( (pTerm->eOperator & WO_IN)!=0 ) iIn--;
if( j<16 && (pLoop->u.vtab.omitMask>>j)&1 ){
disableTerm(pLevel, pTerm);
}else if( (pTerm->eOperator & WO_IN)!=0
&& sqlite3ExprVectorSize(pTerm->pExpr->pLeft)==1
){
Expr *pCompare; /* The comparison operator */
Expr *pRight; /* RHS of the comparison */
VdbeOp *pOp; /* Opcode to access the value of the IN constraint */
/* Reload the constraint value into reg[iReg+j+2]. The same value
** was loaded into the same register prior to the OP_VFilter, but
** the xFilter implementation might have changed the datatype or
** encoding of the value in the register, so it *must* be reloaded. */
assert( pLevel->u.in.aInLoop!=0 || db->mallocFailed );
if( !db->mallocFailed ){
assert( iIn>=0 && iIn<pLevel->u.in.nIn );
pOp = sqlite3VdbeGetOp(v, pLevel->u.in.aInLoop[iIn].addrInTop);
assert( pOp->opcode==OP_Column || pOp->opcode==OP_Rowid );
assert( pOp->opcode!=OP_Column || pOp->p3==iReg+j+2 );
assert( pOp->opcode!=OP_Rowid || pOp->p2==iReg+j+2 );
testcase( pOp->opcode==OP_Rowid );
sqlite3VdbeAddOp3(v, pOp->opcode, pOp->p1, pOp->p2, pOp->p3);
}
/* Generate code that will continue to the next row if
** the IN constraint is not satisfied */
pCompare = sqlite3PExpr(pParse, TK_EQ, 0, 0);
assert( pCompare!=0 || db->mallocFailed );
if( pCompare ){
pCompare->pLeft = pTerm->pExpr->pLeft;
pCompare->pRight = pRight = sqlite3Expr(db, TK_REGISTER, 0);
if( pRight ){
pRight->iTable = iReg+j+2;
sqlite3ExprIfFalse(
pParse, pCompare, pLevel->addrCont, SQLITE_JUMPIFNULL
);
}
pCompare->pLeft = 0;
sqlite3ExprDelete(db, pCompare);
}
}
}
assert( iIn==0 || db->mallocFailed );
/* These registers need to be preserved in case there is an IN operator
** loop. So we could deallocate the registers here (and potentially
** reuse them later) if (pLoop->wsFlags & WHERE_IN_ABLE)==0. But it seems
** simpler and safer to simply not reuse the registers.
**
** sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2);
*/
}else
#endif /* SQLITE_OMIT_VIRTUALTABLE */
if( (pLoop->wsFlags & WHERE_IPK)!=0
&& (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
){
/* Case 2: We can directly reference a single row using an
** equality comparison against the ROWID field. Or
** we reference multiple rows using a "rowid IN (...)"
** construct.
*/
assert( pLoop->u.btree.nEq==1 );
pTerm = pLoop->aLTerm[0];
assert( pTerm!=0 );
assert( pTerm->pExpr!=0 );
testcase( pTerm->wtFlags & TERM_VIRTUAL );
iReleaseReg = ++pParse->nMem;
iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg);
addrNxt = pLevel->addrNxt;
sqlite3VdbeAddOp3(v, OP_SeekRowid, iCur, addrNxt, iRowidReg);
VdbeCoverage(v);
pLevel->op = OP_Noop;
if( (pTerm->prereqAll & pLevel->notReady)==0 ){
pTerm->wtFlags |= TERM_CODED;
}
}else if( (pLoop->wsFlags & WHERE_IPK)!=0
&& (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
){
/* Case 3: We have an inequality comparison against the ROWID field.
*/
int testOp = OP_Noop;
int start;
int memEndValue = 0;
WhereTerm *pStart, *pEnd;
j = 0;
pStart = pEnd = 0;
if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
assert( pStart!=0 || pEnd!=0 );
if( bRev ){
pTerm = pStart;
pStart = pEnd;
pEnd = pTerm;
}
codeCursorHint(pTabItem, pWInfo, pLevel, pEnd);
if( pStart ){
Expr *pX; /* The expression that defines the start bound */
int r1, rTemp; /* Registers for holding the start boundary */
int op; /* Cursor seek operation */
/* The following constant maps TK_xx codes into corresponding
** seek opcodes. It depends on a particular ordering of TK_xx
*/
const u8 aMoveOp[] = {
/* TK_GT */ OP_SeekGT,
/* TK_LE */ OP_SeekLE,
/* TK_LT */ OP_SeekLT,
/* TK_GE */ OP_SeekGE
};
assert( TK_LE==TK_GT+1 ); /* Make sure the ordering.. */
assert( TK_LT==TK_GT+2 ); /* ... of the TK_xx values... */
assert( TK_GE==TK_GT+3 ); /* ... is correcct. */
assert( (pStart->wtFlags & TERM_VNULL)==0 );
testcase( pStart->wtFlags & TERM_VIRTUAL );
pX = pStart->pExpr;
assert( pX!=0 );
testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
if( sqlite3ExprIsVector(pX->pRight) ){
r1 = rTemp = sqlite3GetTempReg(pParse);
codeExprOrVector(pParse, pX->pRight, r1, 1);
testcase( pX->op==TK_GT );
testcase( pX->op==TK_GE );
testcase( pX->op==TK_LT );
testcase( pX->op==TK_LE );
op = aMoveOp[((pX->op - TK_GT - 1) & 0x3) | 0x1];
assert( pX->op!=TK_GT || op==OP_SeekGE );
assert( pX->op!=TK_GE || op==OP_SeekGE );
assert( pX->op!=TK_LT || op==OP_SeekLE );
assert( pX->op!=TK_LE || op==OP_SeekLE );
}else{
r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
disableTerm(pLevel, pStart);
op = aMoveOp[(pX->op - TK_GT)];
}
sqlite3VdbeAddOp3(v, op, iCur, addrBrk, r1);
VdbeComment((v, "pk"));
VdbeCoverageIf(v, pX->op==TK_GT);
VdbeCoverageIf(v, pX->op==TK_LE);
VdbeCoverageIf(v, pX->op==TK_LT);
VdbeCoverageIf(v, pX->op==TK_GE);
sqlite3ReleaseTempReg(pParse, rTemp);
}else{
sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrHalt);
VdbeCoverageIf(v, bRev==0);
VdbeCoverageIf(v, bRev!=0);
}
if( pEnd ){
Expr *pX;
pX = pEnd->pExpr;
assert( pX!=0 );
assert( (pEnd->wtFlags & TERM_VNULL)==0 );
testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
testcase( pEnd->wtFlags & TERM_VIRTUAL );
memEndValue = ++pParse->nMem;
codeExprOrVector(pParse, pX->pRight, memEndValue, 1);
if( 0==sqlite3ExprIsVector(pX->pRight)
&& (pX->op==TK_LT || pX->op==TK_GT)
){
testOp = bRev ? OP_Le : OP_Ge;
}else{
testOp = bRev ? OP_Lt : OP_Gt;
}
if( 0==sqlite3ExprIsVector(pX->pRight) ){
disableTerm(pLevel, pEnd);
}
}
start = sqlite3VdbeCurrentAddr(v);
pLevel->op = bRev ? OP_Prev : OP_Next;
pLevel->p1 = iCur;
pLevel->p2 = start;
assert( pLevel->p5==0 );
if( testOp!=OP_Noop ){
iRowidReg = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
VdbeCoverageIf(v, testOp==OP_Le);
VdbeCoverageIf(v, testOp==OP_Lt);
VdbeCoverageIf(v, testOp==OP_Ge);
VdbeCoverageIf(v, testOp==OP_Gt);
sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
}
}else if( pLoop->wsFlags & WHERE_INDEXED ){
/* Case 4: A scan using an index.
**
** The WHERE clause may contain zero or more equality
** terms ("==" or "IN" operators) that refer to the N
** left-most columns of the index. It may also contain
** inequality constraints (>, <, >= or <=) on the indexed
** column that immediately follows the N equalities. Only
** the right-most column can be an inequality - the rest must
** use the "==" and "IN" operators. For example, if the
** index is on (x,y,z), then the following clauses are all
** optimized:
**
** x=5
** x=5 AND y=10
** x=5 AND y<10
** x=5 AND y>5 AND y<10
** x=5 AND y=5 AND z<=10
**
** The z<10 term of the following cannot be used, only
** the x=5 term:
**
** x=5 AND z<10
**
** N may be zero if there are inequality constraints.
** If there are no inequality constraints, then N is at
** least one.
**
** This case is also used when there are no WHERE clause
** constraints but an index is selected anyway, in order
** to force the output order to conform to an ORDER BY.
*/
static const u8 aStartOp[] = {
0,
0,
OP_Rewind, /* 2: (!start_constraints && startEq && !bRev) */
OP_Last, /* 3: (!start_constraints && startEq && bRev) */
OP_SeekGT, /* 4: (start_constraints && !startEq && !bRev) */
OP_SeekLT, /* 5: (start_constraints && !startEq && bRev) */
OP_SeekGE, /* 6: (start_constraints && startEq && !bRev) */
OP_SeekLE /* 7: (start_constraints && startEq && bRev) */
};
static const u8 aEndOp[] = {
OP_IdxGE, /* 0: (end_constraints && !bRev && !endEq) */
OP_IdxGT, /* 1: (end_constraints && !bRev && endEq) */
OP_IdxLE, /* 2: (end_constraints && bRev && !endEq) */
OP_IdxLT, /* 3: (end_constraints && bRev && endEq) */
};
u16 nEq = pLoop->u.btree.nEq; /* Number of == or IN terms */
u16 nBtm = pLoop->u.btree.nBtm; /* Length of BTM vector */
u16 nTop = pLoop->u.btree.nTop; /* Length of TOP vector */
int regBase; /* Base register holding constraint values */
WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */
WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */
int startEq; /* True if range start uses ==, >= or <= */
int endEq; /* True if range end uses ==, >= or <= */
int start_constraints; /* Start of range is constrained */
int nConstraint; /* Number of constraint terms */
int iIdxCur; /* The VDBE cursor for the index */
int nExtraReg = 0; /* Number of extra registers needed */
int op; /* Instruction opcode */
char *zStartAff; /* Affinity for start of range constraint */
char *zEndAff = 0; /* Affinity for end of range constraint */
u8 bSeekPastNull = 0; /* True to seek past initial nulls */
u8 bStopAtNull = 0; /* Add condition to terminate at NULLs */
int omitTable; /* True if we use the index only */
int regBignull = 0; /* big-null flag register */
int addrSeekScan = 0; /* Opcode of the OP_SeekScan, if any */
pIdx = pLoop->u.btree.pIndex;
iIdxCur = pLevel->iIdxCur;
assert( nEq>=pLoop->nSkip );
/* Find any inequality constraint terms for the start and end
** of the range.
*/
j = nEq;
if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
pRangeStart = pLoop->aLTerm[j++];
nExtraReg = MAX(nExtraReg, pLoop->u.btree.nBtm);
/* Like optimization range constraints always occur in pairs */
assert( (pRangeStart->wtFlags & TERM_LIKEOPT)==0 ||
(pLoop->wsFlags & WHERE_TOP_LIMIT)!=0 );
}
if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
pRangeEnd = pLoop->aLTerm[j++];
nExtraReg = MAX(nExtraReg, pLoop->u.btree.nTop);
#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
if( (pRangeEnd->wtFlags & TERM_LIKEOPT)!=0 ){
assert( pRangeStart!=0 ); /* LIKE opt constraints */
assert( pRangeStart->wtFlags & TERM_LIKEOPT ); /* occur in pairs */
pLevel->iLikeRepCntr = (u32)++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 1, (int)pLevel->iLikeRepCntr);
VdbeComment((v, "LIKE loop counter"));
pLevel->addrLikeRep = sqlite3VdbeCurrentAddr(v);
/* iLikeRepCntr actually stores 2x the counter register number. The
** bottom bit indicates whether the search order is ASC or DESC. */
testcase( bRev );
testcase( pIdx->aSortOrder[nEq]==SQLITE_SO_DESC );
assert( (bRev & ~1)==0 );
pLevel->iLikeRepCntr <<=1;
pLevel->iLikeRepCntr |= bRev ^ (pIdx->aSortOrder[nEq]==SQLITE_SO_DESC);
}
#endif
if( pRangeStart==0 ){
j = pIdx->aiColumn[nEq];
if( (j>=0 && pIdx->pTable->aCol[j].notNull==0) || j==XN_EXPR ){
bSeekPastNull = 1;
}
}
}
assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 );
/* If the WHERE_BIGNULL_SORT flag is set, then index column nEq uses
** a non-default "big-null" sort (either ASC NULLS LAST or DESC NULLS
** FIRST). In both cases separate ordered scans are made of those
** index entries for which the column is null and for those for which
** it is not. For an ASC sort, the non-NULL entries are scanned first.
** For DESC, NULL entries are scanned first.
*/
if( (pLoop->wsFlags & (WHERE_TOP_LIMIT|WHERE_BTM_LIMIT))==0
&& (pLoop->wsFlags & WHERE_BIGNULL_SORT)!=0
){
assert( bSeekPastNull==0 && nExtraReg==0 && nBtm==0 && nTop==0 );
assert( pRangeEnd==0 && pRangeStart==0 );
testcase( pLoop->nSkip>0 );
nExtraReg = 1;
bSeekPastNull = 1;
pLevel->regBignull = regBignull = ++pParse->nMem;
if( pLevel->iLeftJoin ){
sqlite3VdbeAddOp2(v, OP_Integer, 0, regBignull);
}
pLevel->addrBignull = sqlite3VdbeMakeLabel(pParse);
}
/* If we are doing a reverse order scan on an ascending index, or
** a forward order scan on a descending index, interchange the
** start and end terms (pRangeStart and pRangeEnd).
*/
if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
|| (bRev && pIdx->nKeyCol==nEq)
){
SWAP(WhereTerm *, pRangeEnd, pRangeStart);
SWAP(u8, bSeekPastNull, bStopAtNull);
SWAP(u8, nBtm, nTop);
}
/* Generate code to evaluate all constraint terms using == or IN
** and store the values of those terms in an array of registers
** starting at regBase.
*/
codeCursorHint(pTabItem, pWInfo, pLevel, pRangeEnd);
regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq );
if( zStartAff && nTop ){
zEndAff = sqlite3DbStrDup(db, &zStartAff[nEq]);
}
addrNxt = (regBignull ? pLevel->addrBignull : pLevel->addrNxt);
testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
start_constraints = pRangeStart || nEq>0;
/* Seek the index cursor to the start of the range. */
nConstraint = nEq;
if( pRangeStart ){
Expr *pRight = pRangeStart->pExpr->pRight;
codeExprOrVector(pParse, pRight, regBase+nEq, nBtm);
whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
if( (pRangeStart->wtFlags & TERM_VNULL)==0
&& sqlite3ExprCanBeNull(pRight)
){
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
VdbeCoverage(v);
}
if( zStartAff ){
updateRangeAffinityStr(pRight, nBtm, &zStartAff[nEq]);
}
nConstraint += nBtm;
testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
if( sqlite3ExprIsVector(pRight)==0 ){
disableTerm(pLevel, pRangeStart);
}else{
startEq = 1;
}
bSeekPastNull = 0;
}else if( bSeekPastNull ){
startEq = 0;
sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
start_constraints = 1;
nConstraint++;
}else if( regBignull ){
sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
start_constraints = 1;
nConstraint++;
}
codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff);
if( pLoop->nSkip>0 && nConstraint==pLoop->nSkip ){
/* The skip-scan logic inside the call to codeAllEqualityConstraints()
** above has already left the cursor sitting on the correct row,
** so no further seeking is needed */
}else{
if( regBignull ){
sqlite3VdbeAddOp2(v, OP_Integer, 1, regBignull);
VdbeComment((v, "NULL-scan pass ctr"));
}
op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
assert( op!=0 );
if( (pLoop->wsFlags & WHERE_IN_SEEKSCAN)!=0 && op==OP_SeekGE ){
assert( regBignull==0 );
/* TUNING: The OP_SeekScan opcode seeks to reduce the number
** of expensive seek operations by replacing a single seek with
** 1 or more step operations. The question is, how many steps
** should we try before giving up and going with a seek. The cost
** of a seek is proportional to the logarithm of the of the number
** of entries in the tree, so basing the number of steps to try
** on the estimated number of rows in the btree seems like a good
** guess. */
addrSeekScan = sqlite3VdbeAddOp1(v, OP_SeekScan,
(pIdx->aiRowLogEst[0]+9)/10);
VdbeCoverage(v);
}
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
VdbeCoverage(v);
VdbeCoverageIf(v, op==OP_Rewind); testcase( op==OP_Rewind );
VdbeCoverageIf(v, op==OP_Last); testcase( op==OP_Last );
VdbeCoverageIf(v, op==OP_SeekGT); testcase( op==OP_SeekGT );
VdbeCoverageIf(v, op==OP_SeekGE); testcase( op==OP_SeekGE );
VdbeCoverageIf(v, op==OP_SeekLE); testcase( op==OP_SeekLE );
VdbeCoverageIf(v, op==OP_SeekLT); testcase( op==OP_SeekLT );
assert( bSeekPastNull==0 || bStopAtNull==0 );
if( regBignull ){
assert( bSeekPastNull==1 || bStopAtNull==1 );
assert( bSeekPastNull==!bStopAtNull );
assert( bStopAtNull==startEq );
sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+2);
op = aStartOp[(nConstraint>1)*4 + 2 + bRev];
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase,
nConstraint-startEq);
VdbeCoverage(v);
VdbeCoverageIf(v, op==OP_Rewind); testcase( op==OP_Rewind );
VdbeCoverageIf(v, op==OP_Last); testcase( op==OP_Last );
VdbeCoverageIf(v, op==OP_SeekGE); testcase( op==OP_SeekGE );
VdbeCoverageIf(v, op==OP_SeekLE); testcase( op==OP_SeekLE );
assert( op==OP_Rewind || op==OP_Last || op==OP_SeekGE || op==OP_SeekLE);
}
}
/* Load the value for the inequality constraint at the end of the
** range (if any).
*/
nConstraint = nEq;
if( pRangeEnd ){
Expr *pRight = pRangeEnd->pExpr->pRight;
codeExprOrVector(pParse, pRight, regBase+nEq, nTop);
whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
if( (pRangeEnd->wtFlags & TERM_VNULL)==0
&& sqlite3ExprCanBeNull(pRight)
){
sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
VdbeCoverage(v);
}
if( zEndAff ){
updateRangeAffinityStr(pRight, nTop, zEndAff);
codeApplyAffinity(pParse, regBase+nEq, nTop, zEndAff);
}else{
assert( pParse->db->mallocFailed );
}
nConstraint += nTop;
testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
if( sqlite3ExprIsVector(pRight)==0 ){
disableTerm(pLevel, pRangeEnd);
}else{
endEq = 1;
}
}else if( bStopAtNull ){
if( regBignull==0 ){
sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
endEq = 0;
}
nConstraint++;
}
sqlite3DbFree(db, zStartAff);
sqlite3DbFree(db, zEndAff);
/* Top of the loop body */
pLevel->p2 = sqlite3VdbeCurrentAddr(v);
/* Check if the index cursor is past the end of the range. */
if( nConstraint ){
if( regBignull ){
/* Except, skip the end-of-range check while doing the NULL-scan */
sqlite3VdbeAddOp2(v, OP_IfNot, regBignull, sqlite3VdbeCurrentAddr(v)+3);
VdbeComment((v, "If NULL-scan 2nd pass"));
VdbeCoverage(v);
}
op = aEndOp[bRev*2 + endEq];
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT );
testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE );
testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT );
testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE );
if( addrSeekScan ) sqlite3VdbeJumpHere(v, addrSeekScan);
}
if( regBignull ){
/* During a NULL-scan, check to see if we have reached the end of
** the NULLs */
assert( bSeekPastNull==!bStopAtNull );
assert( bSeekPastNull+bStopAtNull==1 );
assert( nConstraint+bSeekPastNull>0 );
sqlite3VdbeAddOp2(v, OP_If, regBignull, sqlite3VdbeCurrentAddr(v)+2);
VdbeComment((v, "If NULL-scan 1st pass"));
VdbeCoverage(v);
op = aEndOp[bRev*2 + bSeekPastNull];
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase,
nConstraint+bSeekPastNull);
testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT );
testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE );
testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT );
testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE );
}
if( (pLoop->wsFlags & WHERE_IN_EARLYOUT)!=0 ){
sqlite3VdbeAddOp3(v, OP_SeekHit, iIdxCur, nEq, nEq);
}
/* Seek the table cursor, if required */
omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0;
if( omitTable ){
/* pIdx is a covering index. No need to access the main table. */
}else if( HasRowid(pIdx->pTable) ){
codeDeferredSeek(pWInfo, pIdx, iCur, iIdxCur);
}else if( iCur!=iIdxCur ){
Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable);
iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol);
for(j=0; j<pPk->nKeyCol; j++){
k = sqlite3TableColumnToIndex(pIdx, pPk->aiColumn[j]);
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j);
}
sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont,
iRowidReg, pPk->nKeyCol); VdbeCoverage(v);
}
if( pLevel->iLeftJoin==0 ){
/* If pIdx is an index on one or more expressions, then look through
** all the expressions in pWInfo and try to transform matching expressions
** into reference to index columns. Also attempt to translate references
** to virtual columns in the table into references to (stored) columns
** of the index.
**
** Do not do this for the RHS of a LEFT JOIN. This is because the
** expression may be evaluated after OP_NullRow has been executed on
** the cursor. In this case it is important to do the full evaluation,
** as the result of the expression may not be NULL, even if all table
** column values are. https://www.sqlite.org/src/info/7fa8049685b50b5a
**
** Also, do not do this when processing one index an a multi-index
** OR clause, since the transformation will become invalid once we
** move forward to the next index.
** https://sqlite.org/src/info/4e8e4857d32d401f
*/
if( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0 ){
whereIndexExprTrans(pIdx, iCur, iIdxCur, pWInfo);
}
/* If a partial index is driving the loop, try to eliminate WHERE clause
** terms from the query that must be true due to the WHERE clause of
** the partial index.
**
** 2019-11-02 ticket 623eff57e76d45f6: This optimization does not work
** for a LEFT JOIN.
*/
if( pIdx->pPartIdxWhere ){
whereApplyPartialIndexConstraints(pIdx->pPartIdxWhere, iCur, pWC);
}
}else{
testcase( pIdx->pPartIdxWhere );
/* The following assert() is not a requirement, merely an observation:
** The OR-optimization doesn't work for the right hand table of
** a LEFT JOIN: */
assert( (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0 );
}
/* Record the instruction used to terminate the loop. */
if( pLoop->wsFlags & WHERE_ONEROW ){
pLevel->op = OP_Noop;
}else if( bRev ){
pLevel->op = OP_Prev;
}else{
pLevel->op = OP_Next;
}
pLevel->p1 = iIdxCur;
pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0;
if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
}else{
assert( pLevel->p5==0 );
}
if( omitTable ) pIdx = 0;
}else
#ifndef SQLITE_OMIT_OR_OPTIMIZATION
if( pLoop->wsFlags & WHERE_MULTI_OR ){
/* Case 5: Two or more separately indexed terms connected by OR
**
** Example:
**
** CREATE TABLE t1(a,b,c,d);
** CREATE INDEX i1 ON t1(a);
** CREATE INDEX i2 ON t1(b);
** CREATE INDEX i3 ON t1(c);
**
** SELECT * FROM t1 WHERE a=5 OR b=7 OR (c=11 AND d=13)
**
** In the example, there are three indexed terms connected by OR.
** The top of the loop looks like this:
**
** Null 1 # Zero the rowset in reg 1
**
** Then, for each indexed term, the following. The arguments to
** RowSetTest are such that the rowid of the current row is inserted
** into the RowSet. If it is already present, control skips the
** Gosub opcode and jumps straight to the code generated by WhereEnd().
**
** sqlite3WhereBegin(<term>)
** RowSetTest # Insert rowid into rowset
** Gosub 2 A
** sqlite3WhereEnd()
**
** Following the above, code to terminate the loop. Label A, the target
** of the Gosub above, jumps to the instruction right after the Goto.
**
** Null 1 # Zero the rowset in reg 1
** Goto B # The loop is finished.
**
** A: <loop body> # Return data, whatever.
**
** Return 2 # Jump back to the Gosub
**
** B: <after the loop>
**
** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
** use an ephemeral index instead of a RowSet to record the primary
** keys of the rows we have already seen.
**
*/
WhereClause *pOrWc; /* The OR-clause broken out into subterms */
SrcList *pOrTab; /* Shortened table list or OR-clause generation */
Index *pCov = 0; /* Potential covering index (or NULL) */
int iCovCur = pParse->nTab++; /* Cursor used for index scans (if any) */
int regReturn = ++pParse->nMem; /* Register used with OP_Gosub */
int regRowset = 0; /* Register for RowSet object */
int regRowid = 0; /* Register holding rowid */
int iLoopBody = sqlite3VdbeMakeLabel(pParse);/* Start of loop body */
int iRetInit; /* Address of regReturn init */
int untestedTerms = 0; /* Some terms not completely tested */
int ii; /* Loop counter */
Expr *pAndExpr = 0; /* An ".. AND (...)" expression */
Table *pTab = pTabItem->pTab;
pTerm = pLoop->aLTerm[0];
assert( pTerm!=0 );
assert( pTerm->eOperator & WO_OR );
assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
pOrWc = &pTerm->u.pOrInfo->wc;
pLevel->op = OP_Return;
pLevel->p1 = regReturn;
/* Set up a new SrcList in pOrTab containing the table being scanned
** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
*/
if( pWInfo->nLevel>1 ){
int nNotReady; /* The number of notReady tables */
struct SrcList_item *origSrc; /* Original list of tables */
nNotReady = pWInfo->nLevel - iLevel - 1;
pOrTab = sqlite3StackAllocRaw(db,
sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
if( pOrTab==0 ) return notReady;
pOrTab->nAlloc = (u8)(nNotReady + 1);
pOrTab->nSrc = pOrTab->nAlloc;
memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
origSrc = pWInfo->pTabList->a;
for(k=1; k<=nNotReady; k++){
memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
}
}else{
pOrTab = pWInfo->pTabList;
}
/* Initialize the rowset register to contain NULL. An SQL NULL is
** equivalent to an empty rowset. Or, create an ephemeral index
** capable of holding primary keys in the case of a WITHOUT ROWID.
**
** Also initialize regReturn to contain the address of the instruction
** immediately following the OP_Return at the bottom of the loop. This
** is required in a few obscure LEFT JOIN cases where control jumps
** over the top of the loop into the body of it. In this case the
** correct response for the end-of-loop code (the OP_Return) is to
** fall through to the next instruction, just as an OP_Next does if
** called on an uninitialized cursor.
*/
if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
if( HasRowid(pTab) ){
regRowset = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
}else{
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
regRowset = pParse->nTab++;
sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol);
sqlite3VdbeSetP4KeyInfo(pParse, pPk);
}
regRowid = ++pParse->nMem;
}
iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);
/* If the original WHERE clause is z of the form: (x1 OR x2 OR ...) AND y
** Then for every term xN, evaluate as the subexpression: xN AND z
** That way, terms in y that are factored into the disjunction will
** be picked up by the recursive calls to sqlite3WhereBegin() below.
**
** Actually, each subexpression is converted to "xN AND w" where w is
** the "interesting" terms of z - terms that did not originate in the
** ON or USING clause of a LEFT JOIN, and terms that are usable as
** indices.
**
** This optimization also only applies if the (x1 OR x2 OR ...) term
** is not contained in the ON clause of a LEFT JOIN.
** See ticket http://www.sqlite.org/src/info/f2369304e4
*/
if( pWC->nTerm>1 ){
int iTerm;
for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
Expr *pExpr = pWC->a[iTerm].pExpr;
if( &pWC->a[iTerm] == pTerm ) continue;
testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );
testcase( pWC->a[iTerm].wtFlags & TERM_CODED );
if( (pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_CODED))!=0 ) continue;
if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
pExpr = sqlite3ExprDup(db, pExpr, 0);
pAndExpr = sqlite3ExprAnd(pParse, pAndExpr, pExpr);
}
if( pAndExpr ){
/* The extra 0x10000 bit on the opcode is masked off and does not
** become part of the new Expr.op. However, it does make the
** op==TK_AND comparison inside of sqlite3PExpr() false, and this
** prevents sqlite3PExpr() from implementing AND short-circuit
** optimization, which we do not want here. */
pAndExpr = sqlite3PExpr(pParse, TK_AND|0x10000, 0, pAndExpr);
}
}
/* Run a separate WHERE clause for each term of the OR clause. After
** eliminating duplicates from other WHERE clauses, the action for each
** sub-WHERE clause is to to invoke the main loop body as a subroutine.
*/
ExplainQueryPlan((pParse, 1, "MULTI-INDEX OR"));
for(ii=0; ii<pOrWc->nTerm; ii++){
WhereTerm *pOrTerm = &pOrWc->a[ii];
if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
WhereInfo *pSubWInfo; /* Info for single OR-term scan */
Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */
int jmp1 = 0; /* Address of jump operation */
testcase( (pTabItem[0].fg.jointype & JT_LEFT)!=0
&& !ExprHasProperty(pOrExpr, EP_FromJoin)
); /* See TH3 vtab25.400 and ticket 614b25314c766238 */
if( pAndExpr ){
pAndExpr->pLeft = pOrExpr;
pOrExpr = pAndExpr;
}
/* Loop through table entries that match term pOrTerm. */
ExplainQueryPlan((pParse, 1, "INDEX %d", ii+1));
WHERETRACE(0xffff, ("Subplan for OR-clause:\n"));
pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
WHERE_OR_SUBCLAUSE, iCovCur);
assert( pSubWInfo || pParse->nErr || db->mallocFailed );
if( pSubWInfo ){
WhereLoop *pSubLoop;
int addrExplain = sqlite3WhereExplainOneScan(
pParse, pOrTab, &pSubWInfo->a[0], 0
);
sqlite3WhereAddScanStatus(v, pOrTab, &pSubWInfo->a[0], addrExplain);
/* This is the sub-WHERE clause body. First skip over
** duplicate rows from prior sub-WHERE clauses, and record the
** rowid (or PRIMARY KEY) for the current row so that the same
** row will be skipped in subsequent sub-WHERE clauses.
*/
if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
if( HasRowid(pTab) ){
sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, -1, regRowid);
jmp1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0,
regRowid, iSet);
VdbeCoverage(v);
}else{
Index *pPk = sqlite3PrimaryKeyIndex(pTab);
int nPk = pPk->nKeyCol;
int iPk;
int r;
/* Read the PK into an array of temp registers. */
r = sqlite3GetTempRange(pParse, nPk);
for(iPk=0; iPk<nPk; iPk++){
int iCol = pPk->aiColumn[iPk];
sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, iCol,r+iPk);
}
/* Check if the temp table already contains this key. If so,
** the row has already been included in the result set and
** can be ignored (by jumping past the Gosub below). Otherwise,
** insert the key into the temp table and proceed with processing
** the row.
**
** Use some of the same optimizations as OP_RowSetTest: If iSet
** is zero, assume that the key cannot already be present in
** the temp table. And if iSet is -1, assume that there is no
** need to insert the key into the temp table, as it will never
** be tested for. */
if( iSet ){
jmp1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);
VdbeCoverage(v);
}
if( iSet>=0 ){
sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid);
sqlite3VdbeAddOp4Int(v, OP_IdxInsert, regRowset, regRowid,
r, nPk);
if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
}
/* Release the array of temp registers */
sqlite3ReleaseTempRange(pParse, r, nPk);
}
}
/* Invoke the main loop body as a subroutine */
sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
/* Jump here (skipping the main loop body subroutine) if the
** current sub-WHERE row is a duplicate from prior sub-WHEREs. */
if( jmp1 ) sqlite3VdbeJumpHere(v, jmp1);
/* The pSubWInfo->untestedTerms flag means that this OR term
** contained one or more AND term from a notReady table. The
** terms from the notReady table could not be tested and will
** need to be tested later.
*/
if( pSubWInfo->untestedTerms ) untestedTerms = 1;
/* If all of the OR-connected terms are optimized using the same
** index, and the index is opened using the same cursor number
** by each call to sqlite3WhereBegin() made by this loop, it may
** be possible to use that index as a covering index.
**
** If the call to sqlite3WhereBegin() above resulted in a scan that
** uses an index, and this is either the first OR-connected term
** processed or the index is the same as that used by all previous
** terms, set pCov to the candidate covering index. Otherwise, set
** pCov to NULL to indicate that no candidate covering index will
** be available.
*/
pSubLoop = pSubWInfo->a[0].pWLoop;
assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
&& (ii==0 || pSubLoop->u.btree.pIndex==pCov)
&& (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex))
){
assert( pSubWInfo->a[0].iIdxCur==iCovCur );
pCov = pSubLoop->u.btree.pIndex;
}else{
pCov = 0;
}
if( sqlite3WhereUsesDeferredSeek(pSubWInfo) ){
pWInfo->bDeferredSeek = 1;
}
/* Finish the loop through table entries that match term pOrTerm. */
sqlite3WhereEnd(pSubWInfo);
ExplainQueryPlanPop(pParse);
}
}
}
ExplainQueryPlanPop(pParse);
pLevel->u.pCovidx = pCov;
if( pCov ) pLevel->iIdxCur = iCovCur;
if( pAndExpr ){
pAndExpr->pLeft = 0;
sqlite3ExprDelete(db, pAndExpr);
}
sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
sqlite3VdbeGoto(v, pLevel->addrBrk);
sqlite3VdbeResolveLabel(v, iLoopBody);
if( pWInfo->nLevel>1 ){ sqlite3StackFree(db, pOrTab); }
if( !untestedTerms ) disableTerm(pLevel, pTerm);
}else
#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
{
/* Case 6: There is no usable index. We must do a complete
** scan of the entire table.
*/
static const u8 aStep[] = { OP_Next, OP_Prev };
static const u8 aStart[] = { OP_Rewind, OP_Last };
assert( bRev==0 || bRev==1 );
if( pTabItem->fg.isRecursive ){
/* Tables marked isRecursive have only a single row that is stored in
** a pseudo-cursor. No need to Rewind or Next such cursors. */
pLevel->op = OP_Noop;
}else{
codeCursorHint(pTabItem, pWInfo, pLevel, 0);
pLevel->op = aStep[bRev];
pLevel->p1 = iCur;
pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrHalt);
VdbeCoverageIf(v, bRev==0);
VdbeCoverageIf(v, bRev!=0);
pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
}
}
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
pLevel->addrVisit = sqlite3VdbeCurrentAddr(v);
#endif
/* Insert code to test every subexpression that can be completely
** computed using the current set of tables.
**
** This loop may run between one and three times, depending on the
** constraints to be generated. The value of stack variable iLoop
** determines the constraints coded by each iteration, as follows:
**
** iLoop==1: Code only expressions that are entirely covered by pIdx.
** iLoop==2: Code remaining expressions that do not contain correlated
** sub-queries.
** iLoop==3: Code all remaining expressions.
**
** An effort is made to skip unnecessary iterations of the loop.
*/
iLoop = (pIdx ? 1 : 2);
do{
int iNext = 0; /* Next value for iLoop */
for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
Expr *pE;
int skipLikeAddr = 0;
testcase( pTerm->wtFlags & TERM_VIRTUAL );
testcase( pTerm->wtFlags & TERM_CODED );
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
testcase( pWInfo->untestedTerms==0
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
pWInfo->untestedTerms = 1;
continue;
}
pE = pTerm->pExpr;
assert( pE!=0 );
if( (pTabItem->fg.jointype&JT_LEFT) && !ExprHasProperty(pE,EP_FromJoin) ){
continue;
}
if( iLoop==1 && !sqlite3ExprCoveredByIndex(pE, pLevel->iTabCur, pIdx) ){
iNext = 2;
continue;
}
if( iLoop<3 && (pTerm->wtFlags & TERM_VARSELECT) ){
if( iNext==0 ) iNext = 3;
continue;
}
if( (pTerm->wtFlags & TERM_LIKECOND)!=0 ){
/* If the TERM_LIKECOND flag is set, that means that the range search
** is sufficient to guarantee that the LIKE operator is true, so we
** can skip the call to the like(A,B) function. But this only works
** for strings. So do not skip the call to the function on the pass
** that compares BLOBs. */
#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
continue;
#else
u32 x = pLevel->iLikeRepCntr;
if( x>0 ){
skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)?OP_IfNot:OP_If,(int)(x>>1));
VdbeCoverageIf(v, (x&1)==1);
VdbeCoverageIf(v, (x&1)==0);
}
#endif
}
#ifdef WHERETRACE_ENABLED /* 0xffff */
if( sqlite3WhereTrace ){
VdbeNoopComment((v, "WhereTerm[%d] (%p) priority=%d",
pWC->nTerm-j, pTerm, iLoop));
}
if( sqlite3WhereTrace & 0x800 ){
sqlite3DebugPrintf("Coding auxiliary constraint:\n");
sqlite3WhereTermPrint(pTerm, pWC->nTerm-j);
}
#endif
sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
pTerm->wtFlags |= TERM_CODED;
}
iLoop = iNext;
}while( iLoop>0 );
/* Insert code to test for implied constraints based on transitivity
** of the "==" operator.
**
** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123"
** and we are coding the t1 loop and the t2 loop has not yet coded,
** then we cannot use the "t1.a=t2.b" constraint, but we can code
** the implied "t1.a=123" constraint.
*/
for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
Expr *pE, sEAlt;
WhereTerm *pAlt;
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) continue;
if( (pTerm->eOperator & WO_EQUIV)==0 ) continue;
if( pTerm->leftCursor!=iCur ) continue;
if( pTabItem->fg.jointype & JT_LEFT ) continue;
pE = pTerm->pExpr;
#ifdef WHERETRACE_ENABLED /* 0x800 */
if( sqlite3WhereTrace & 0x800 ){
sqlite3DebugPrintf("Coding transitive constraint:\n");
sqlite3WhereTermPrint(pTerm, pWC->nTerm-j);
}
#endif
assert( !ExprHasProperty(pE, EP_FromJoin) );
assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
pAlt = sqlite3WhereFindTerm(pWC, iCur, pTerm->u.x.leftColumn, notReady,
WO_EQ|WO_IN|WO_IS, 0);
if( pAlt==0 ) continue;
if( pAlt->wtFlags & (TERM_CODED) ) continue;
if( (pAlt->eOperator & WO_IN)
&& (pAlt->pExpr->flags & EP_xIsSelect)
&& (pAlt->pExpr->x.pSelect->pEList->nExpr>1)
){
continue;
}
testcase( pAlt->eOperator & WO_EQ );
testcase( pAlt->eOperator & WO_IS );
testcase( pAlt->eOperator & WO_IN );
VdbeModuleComment((v, "begin transitive constraint"));
sEAlt = *pAlt->pExpr;
sEAlt.pLeft = pE->pLeft;
sqlite3ExprIfFalse(pParse, &sEAlt, addrCont, SQLITE_JUMPIFNULL);
}
/* For a LEFT OUTER JOIN, generate code that will record the fact that
** at least one row of the right table has matched the left table.
*/
if( pLevel->iLeftJoin ){
pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
VdbeComment((v, "record LEFT JOIN hit"));
for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
testcase( pTerm->wtFlags & TERM_VIRTUAL );
testcase( pTerm->wtFlags & TERM_CODED );
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
assert( pWInfo->untestedTerms );
continue;
}
assert( pTerm->pExpr );
sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
pTerm->wtFlags |= TERM_CODED;
}
}
#if WHERETRACE_ENABLED /* 0x20800 */
if( sqlite3WhereTrace & 0x20000 ){
sqlite3DebugPrintf("All WHERE-clause terms after coding level %d:\n",
iLevel);
sqlite3WhereClausePrint(pWC);
}
if( sqlite3WhereTrace & 0x800 ){
sqlite3DebugPrintf("End Coding level %d: notReady=%llx\n",
iLevel, (u64)pLevel->notReady);
}
#endif
return pLevel->notReady;
}
/************** End of wherecode.c *******************************************/
/************** Begin file whereexpr.c ***************************************/
/*
** 2015-06-08
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.
**
** This file was originally part of where.c but was split out to improve
** readability and editabiliity. This file contains utility routines for
** analyzing Expr objects in the WHERE clause.
*/
/* #include "sqliteInt.h" */
/* #include "whereInt.h" */
/* Forward declarations */
static void exprAnalyze(SrcList*, WhereClause*, int);
/*
** Deallocate all memory associated with a WhereOrInfo object.
*/
static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){
sqlite3WhereClauseClear(&p->wc);
sqlite3DbFree(db, p);
}
/*
** Deallocate all memory associated with a WhereAndInfo object.
*/
static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
sqlite3WhereClauseClear(&p->wc);
sqlite3DbFree(db, p);
}
/*
** Add a single new WhereTerm entry to the WhereClause object pWC.
** The new WhereTerm object is constructed from Expr p and with wtFlags.
** The index in pWC->a[] of the new WhereTerm is returned on success.
** 0 is returned if the new WhereTerm could not be added due to a memory
** allocation error. The memory allocation failure will be recorded in
** the db->mallocFailed flag so that higher-level functions can detect it.
**
** This routine will increase the size of the pWC->a[] array as necessary.
**
** If the wtFlags argument includes TERM_DYNAMIC, then responsibility
** for freeing the expression p is assumed by the WhereClause object pWC.
** This is true even if this routine fails to allocate a new WhereTerm.
**
** WARNING: This routine might reallocate the space used to store
** WhereTerms. All pointers to WhereTerms should be invalidated after
** calling this routine. Such pointers may be reinitialized by referencing
** the pWC->a[] array.
*/
static int whereClauseInsert(WhereClause *pWC, Expr *p, u16 wtFlags){
WhereTerm *pTerm;
int idx;
testcase( wtFlags & TERM_VIRTUAL );
if( pWC->nTerm>=pWC->nSlot ){
WhereTerm *pOld = pWC->a;
sqlite3 *db = pWC->pWInfo->pParse->db;
pWC->a = sqlite3DbMallocRawNN(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
if( pWC->a==0 ){
if( wtFlags & TERM_DYNAMIC ){
sqlite3ExprDelete(db, p);
}
pWC->a = pOld;
return 0;
}
memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm);
if( pOld!=pWC->aStatic ){
sqlite3DbFree(db, pOld);
}
pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
}
pTerm = &pWC->a[idx = pWC->nTerm++];
if( p && ExprHasProperty(p, EP_Unlikely) ){
pTerm->truthProb = sqlite3LogEst(p->iTable) - 270;
}else{
pTerm->truthProb = 1;
}
pTerm->pExpr = sqlite3ExprSkipCollateAndLikely(p);
pTerm->wtFlags = wtFlags;
pTerm->pWC = pWC;
pTerm->iParent = -1;
memset(&pTerm->eOperator, 0,
sizeof(WhereTerm) - offsetof(WhereTerm,eOperator));
return idx;
}
/*
** Return TRUE if the given operator is one of the operators that is
** allowed for an indexable WHERE clause term. The allowed operators are
** "=", "<", ">", "<=", ">=", "IN", "IS", and "IS NULL"
*/
static int allowedOp(int op){
assert( TK_GT>TK_EQ && TK_GT<TK_GE );
assert( TK_LT>TK_EQ && TK_LT<TK_GE );
assert( TK_LE>TK_EQ && TK_LE<TK_GE );
assert( TK_GE==TK_EQ+4 );
return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || op==TK_ISNULL || op==TK_IS;
}
/*
** Commute a comparison operator. Expressions of the form "X op Y"
** are converted into "Y op X".
*/
static u16 exprCommute(Parse *pParse, Expr *pExpr){
if( pExpr->pLeft->op==TK_VECTOR
|| pExpr->pRight->op==TK_VECTOR
|| sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight) !=
sqlite3BinaryCompareCollSeq(pParse, pExpr->pRight, pExpr->pLeft)
){
pExpr->flags ^= EP_Commuted;
}
SWAP(Expr*,pExpr->pRight,pExpr->pLeft);
if( pExpr->op>=TK_GT ){
assert( TK_LT==TK_GT+2 );
assert( TK_GE==TK_LE+2 );
assert( TK_GT>TK_EQ );
assert( TK_GT<TK_LE );
assert( pExpr->op>=TK_GT && pExpr->op<=TK_GE );
pExpr->op = ((pExpr->op-TK_GT)^2)+TK_GT;
}
return 0;
}
/*
** Translate from TK_xx operator to WO_xx bitmask.
*/
static u16 operatorMask(int op){
u16 c;
assert( allowedOp(op) );
if( op==TK_IN ){
c = WO_IN;
}else if( op==TK_ISNULL ){
c = WO_ISNULL;
}else if( op==TK_IS ){
c = WO_IS;
}else{
assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff );
c = (u16)(WO_EQ<<(op-TK_EQ));
}
assert( op!=TK_ISNULL || c==WO_ISNULL );
assert( op!=TK_IN || c==WO_IN );
assert( op!=TK_EQ || c==WO_EQ );
assert( op!=TK_LT || c==WO_LT );
assert( op!=TK_LE || c==WO_LE );
assert( op!=TK_GT || c==WO_GT );
assert( op!=TK_GE || c==WO_GE );
assert( op!=TK_IS || c==WO_IS );
return c;
}
#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
/*
** Check to see if the given expression is a LIKE or GLOB operator that
** can be optimized using inequality constraints. Return TRUE if it is
** so and false if not.
**
** In order for the operator to be optimizible, the RHS must be a string
** literal that does not begin with a wildcard. The LHS must be a column
** that may only be NULL, a string, or a BLOB, never a number. (This means
** that virtual tables cannot participate in the LIKE optimization.) The
** collating sequence for the column on the LHS must be appropriate for
** the operator.
*/
static int isLikeOrGlob(
Parse *pParse, /* Parsing and code generating context */
Expr *pExpr, /* Test this expression */
Expr **ppPrefix, /* Pointer to TK_STRING expression with pattern prefix */
int *pisComplete, /* True if the only wildcard is % in the last character */
int *pnoCase /* True if uppercase is equivalent to lowercase */
){
const u8 *z = 0; /* String on RHS of LIKE operator */
Expr *pRight, *pLeft; /* Right and left size of LIKE operator */
ExprList *pList; /* List of operands to the LIKE operator */
u8 c; /* One character in z[] */
int cnt; /* Number of non-wildcard prefix characters */
u8 wc[4]; /* Wildcard characters */
sqlite3 *db = pParse->db; /* Database connection */
sqlite3_value *pVal = 0;
int op; /* Opcode of pRight */
int rc; /* Result code to return */
if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, (char*)wc) ){
return 0;
}
#ifdef SQLITE_EBCDIC
if( *pnoCase ) return 0;
#endif
pList = pExpr->x.pList;
pLeft = pList->a[1].pExpr;
pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr);
op = pRight->op;
if( op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){
Vdbe *pReprepare = pParse->pReprepare;
int iCol = pRight->iColumn;
pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_BLOB);
if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){
z = sqlite3_value_text(pVal);
}
sqlite3VdbeSetVarmask(pParse->pVdbe, iCol);
assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER );
}else if( op==TK_STRING ){
z = (u8*)pRight->u.zToken;
}
if( z ){
/* Count the number of prefix characters prior to the first wildcard */
cnt = 0;
while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
cnt++;
if( c==wc[3] && z[cnt]!=0 ) cnt++;
}
/* The optimization is possible only if (1) the pattern does not begin
** with a wildcard and if (2) the non-wildcard prefix does not end with
** an (illegal 0xff) character, or (3) the pattern does not consist of
** a single escape character. The second condition is necessary so
** that we can increment the prefix key to find an upper bound for the
** range search. The third is because the caller assumes that the pattern
** consists of at least one character after all escapes have been
** removed. */
if( cnt!=0 && 255!=(u8)z[cnt-1] && (cnt>1 || z[0]!=wc[3]) ){
Expr *pPrefix;
/* A "complete" match if the pattern ends with "*" or "%" */
*pisComplete = c==wc[0] && z[cnt+1]==0;
/* Get the pattern prefix. Remove all escapes from the prefix. */
pPrefix = sqlite3Expr(db, TK_STRING, (char*)z);
if( pPrefix ){
int iFrom, iTo;
char *zNew = pPrefix->u.zToken;
zNew[cnt] = 0;
for(iFrom=iTo=0; iFrom<cnt; iFrom++){
if( zNew[iFrom]==wc[3] ) iFrom++;
zNew[iTo++] = zNew[iFrom];
}
zNew[iTo] = 0;
assert( iTo>0 );
/* If the LHS is not an ordinary column with TEXT affinity, then the
** pattern prefix boundaries (both the start and end boundaries) must
** not look like a number. Otherwise the pattern might be treated as
** a number, which will invalidate the LIKE optimization.
**
** Getting this right has been a persistent source of bugs in the
** LIKE optimization. See, for example:
** 2018-09-10 https://sqlite.org/src/info/c94369cae9b561b1
** 2019-05-02 https://sqlite.org/src/info/b043a54c3de54b28
** 2019-06-10 https://sqlite.org/src/info/fd76310a5e843e07
** 2019-06-14 https://sqlite.org/src/info/ce8717f0885af975
** 2019-09-03 https://sqlite.org/src/info/0f0428096f17252a
*/
if( pLeft->op!=TK_COLUMN
|| sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT
|| IsVirtual(pLeft->y.pTab) /* Value might be numeric */
){
int isNum;
double rDummy;
isNum = sqlite3AtoF(zNew, &rDummy, iTo, SQLITE_UTF8);
if( isNum<=0 ){
if( iTo==1 && zNew[0]=='-' ){
isNum = +1;
}else{
zNew[iTo-1]++;
isNum = sqlite3AtoF(zNew, &rDummy, iTo, SQLITE_UTF8);
zNew[iTo-1]--;
}
}
if( isNum>0 ){
sqlite3ExprDelete(db, pPrefix);
sqlite3ValueFree(pVal);
return 0;
}
}
}
*ppPrefix = pPrefix;
/* If the RHS pattern is a bound parameter, make arrangements to
** reprepare the statement when that parameter is rebound */
if( op==TK_VARIABLE ){
Vdbe *v = pParse->pVdbe;
sqlite3VdbeSetVarmask(v, pRight->iColumn);
if( *pisComplete && pRight->u.zToken[1] ){
/* If the rhs of the LIKE expression is a variable, and the current
** value of the variable means there is no need to invoke the LIKE
** function, then no OP_Variable will be added to the program.
** This causes problems for the sqlite3_bind_parameter_name()
** API. To work around them, add a dummy OP_Variable here.
*/
int r1 = sqlite3GetTempReg(pParse);
sqlite3ExprCodeTarget(pParse, pRight, r1);
sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0);
sqlite3ReleaseTempReg(pParse, r1);
}
}
}else{
z = 0;
}
}
rc = (z!=0);
sqlite3ValueFree(pVal);
return rc;
}
#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Check to see if the pExpr expression is a form that needs to be passed
** to the xBestIndex method of virtual tables. Forms of interest include:
**
** Expression Virtual Table Operator
** ----------------------- ---------------------------------
** 1. column MATCH expr SQLITE_INDEX_CONSTRAINT_MATCH
** 2. column GLOB expr SQLITE_INDEX_CONSTRAINT_GLOB
** 3. column LIKE expr SQLITE_INDEX_CONSTRAINT_LIKE
** 4. column REGEXP expr SQLITE_INDEX_CONSTRAINT_REGEXP
** 5. column != expr SQLITE_INDEX_CONSTRAINT_NE
** 6. expr != column SQLITE_INDEX_CONSTRAINT_NE
** 7. column IS NOT expr SQLITE_INDEX_CONSTRAINT_ISNOT
** 8. expr IS NOT column SQLITE_INDEX_CONSTRAINT_ISNOT
** 9. column IS NOT NULL SQLITE_INDEX_CONSTRAINT_ISNOTNULL
**
** In every case, "column" must be a column of a virtual table. If there
** is a match, set *ppLeft to the "column" expression, set *ppRight to the
** "expr" expression (even though in forms (6) and (8) the column is on the
** right and the expression is on the left). Also set *peOp2 to the
** appropriate virtual table operator. The return value is 1 or 2 if there
** is a match. The usual return is 1, but if the RHS is also a column
** of virtual table in forms (5) or (7) then return 2.
**
** If the expression matches none of the patterns above, return 0.
*/
static int isAuxiliaryVtabOperator(
sqlite3 *db, /* Parsing context */
Expr *pExpr, /* Test this expression */
unsigned char *peOp2, /* OUT: 0 for MATCH, or else an op2 value */
Expr **ppLeft, /* Column expression to left of MATCH/op2 */
Expr **ppRight /* Expression to left of MATCH/op2 */
){
if( pExpr->op==TK_FUNCTION ){
static const struct Op2 {
const char *zOp;
unsigned char eOp2;
} aOp[] = {
{ "match", SQLITE_INDEX_CONSTRAINT_MATCH },
{ "glob", SQLITE_INDEX_CONSTRAINT_GLOB },
{ "like", SQLITE_INDEX_CONSTRAINT_LIKE },
{ "regexp", SQLITE_INDEX_CONSTRAINT_REGEXP }
};
ExprList *pList;
Expr *pCol; /* Column reference */
int i;
pList = pExpr->x.pList;
if( pList==0 || pList->nExpr!=2 ){
return 0;
}
/* Built-in operators MATCH, GLOB, LIKE, and REGEXP attach to a
** virtual table on their second argument, which is the same as
** the left-hand side operand in their in-fix form.
**
** vtab_column MATCH expression
** MATCH(expression,vtab_column)
*/
pCol = pList->a[1].pExpr;
testcase( pCol->op==TK_COLUMN && pCol->y.pTab==0 );
if( ExprIsVtab(pCol) ){
for(i=0; i<ArraySize(aOp); i++){
if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
*peOp2 = aOp[i].eOp2;
*ppRight = pList->a[0].pExpr;
*ppLeft = pCol;
return 1;
}
}
}
/* We can also match against the first column of overloaded
** functions where xFindFunction returns a value of at least
** SQLITE_INDEX_CONSTRAINT_FUNCTION.
**
** OVERLOADED(vtab_column,expression)
**
** Historically, xFindFunction expected to see lower-case function
** names. But for this use case, xFindFunction is expected to deal
** with function names in an arbitrary case.
*/
pCol = pList->a[0].pExpr;
testcase( pCol->op==TK_COLUMN && pCol->y.pTab==0 );
if( ExprIsVtab(pCol) ){
sqlite3_vtab *pVtab;
sqlite3_module *pMod;
void (*xNotUsed)(sqlite3_context*,int,sqlite3_value**);
void *pNotUsed;
pVtab = sqlite3GetVTable(db, pCol->y.pTab)->pVtab;
assert( pVtab!=0 );
assert( pVtab->pModule!=0 );
pMod = (sqlite3_module *)pVtab->pModule;
if( pMod->xFindFunction!=0 ){
i = pMod->xFindFunction(pVtab,2, pExpr->u.zToken, &xNotUsed, &pNotUsed);
if( i>=SQLITE_INDEX_CONSTRAINT_FUNCTION ){
*peOp2 = i;
*ppRight = pList->a[1].pExpr;
*ppLeft = pCol;
return 1;
}
}
}
}else if( pExpr->op==TK_NE || pExpr->op==TK_ISNOT || pExpr->op==TK_NOTNULL ){
int res = 0;
Expr *pLeft = pExpr->pLeft;
Expr *pRight = pExpr->pRight;
testcase( pLeft->op==TK_COLUMN && pLeft->y.pTab==0 );
if( ExprIsVtab(pLeft) ){
res++;
}
testcase( pRight && pRight->op==TK_COLUMN && pRight->y.pTab==0 );
if( pRight && ExprIsVtab(pRight) ){
res++;
SWAP(Expr*, pLeft, pRight);
}
*ppLeft = pLeft;
*ppRight = pRight;
if( pExpr->op==TK_NE ) *peOp2 = SQLITE_INDEX_CONSTRAINT_NE;
if( pExpr->op==TK_ISNOT ) *peOp2 = SQLITE_INDEX_CONSTRAINT_ISNOT;
if( pExpr->op==TK_NOTNULL ) *peOp2 = SQLITE_INDEX_CONSTRAINT_ISNOTNULL;
return res;
}
return 0;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
/*
** If the pBase expression originated in the ON or USING clause of
** a join, then transfer the appropriate markings over to derived.
*/
static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
if( pDerived ){
pDerived->flags |= pBase->flags & EP_FromJoin;
pDerived->iRightJoinTable = pBase->iRightJoinTable;
}
}
/*
** Mark term iChild as being a child of term iParent
*/
static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){
pWC->a[iChild].iParent = iParent;
pWC->a[iChild].truthProb = pWC->a[iParent].truthProb;
pWC->a[iParent].nChild++;
}
/*
** Return the N-th AND-connected subterm of pTerm. Or if pTerm is not
** a conjunction, then return just pTerm when N==0. If N is exceeds
** the number of available subterms, return NULL.
*/
static WhereTerm *whereNthSubterm(WhereTerm *pTerm, int N){
if( pTerm->eOperator!=WO_AND ){
return N==0 ? pTerm : 0;
}
if( N<pTerm->u.pAndInfo->wc.nTerm ){
return &pTerm->u.pAndInfo->wc.a[N];
}
return 0;
}
/*
** Subterms pOne and pTwo are contained within WHERE clause pWC. The
** two subterms are in disjunction - they are OR-ed together.
**
** If these two terms are both of the form: "A op B" with the same
** A and B values but different operators and if the operators are
** compatible (if one is = and the other is <, for example) then
** add a new virtual AND term to pWC that is the combination of the
** two.
**
** Some examples:
**
** x<y OR x=y --> x<=y
** x=y OR x=y --> x=y
** x<=y OR x<y --> x<=y
**
** The following is NOT generated:
**
** x<y OR x>y --> x!=y
*/
static void whereCombineDisjuncts(
SrcList *pSrc, /* the FROM clause */
WhereClause *pWC, /* The complete WHERE clause */
WhereTerm *pOne, /* First disjunct */
WhereTerm *pTwo /* Second disjunct */
){
u16 eOp = pOne->eOperator | pTwo->eOperator;
sqlite3 *db; /* Database connection (for malloc) */
Expr *pNew; /* New virtual expression */
int op; /* Operator for the combined expression */
int idxNew; /* Index in pWC of the next virtual term */
if( (pOne->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
if( (pTwo->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return;
if( (eOp & (WO_EQ|WO_LT|WO_LE))!=eOp
&& (eOp & (WO_EQ|WO_GT|WO_GE))!=eOp ) return;
assert( pOne->pExpr->pLeft!=0 && pOne->pExpr->pRight!=0 );
assert( pTwo->pExpr->pLeft!=0 && pTwo->pExpr->pRight!=0 );
if( sqlite3ExprCompare(0,pOne->pExpr->pLeft, pTwo->pExpr->pLeft, -1) ) return;
if( sqlite3ExprCompare(0,pOne->pExpr->pRight, pTwo->pExpr->pRight,-1) )return;
/* If we reach this point, it means the two subterms can be combined */
if( (eOp & (eOp-1))!=0 ){
if( eOp & (WO_LT|WO_LE) ){
eOp = WO_LE;
}else{
assert( eOp & (WO_GT|WO_GE) );
eOp = WO_GE;
}
}
db = pWC->pWInfo->pParse->db;
pNew = sqlite3ExprDup(db, pOne->pExpr, 0);
if( pNew==0 ) return;
for(op=TK_EQ; eOp!=(WO_EQ<<(op-TK_EQ)); op++){ assert( op<TK_GE ); }
pNew->op = op;
idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
exprAnalyze(pSrc, pWC, idxNew);
}
#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
/*
** Analyze a term that consists of two or more OR-connected
** subterms. So in:
**
** ... WHERE (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13)
** ^^^^^^^^^^^^^^^^^^^^
**
** This routine analyzes terms such as the middle term in the above example.
** A WhereOrTerm object is computed and attached to the term under
** analysis, regardless of the outcome of the analysis. Hence:
**
** WhereTerm.wtFlags |= TERM_ORINFO
** WhereTerm.u.pOrInfo = a dynamically allocated WhereOrTerm object
**
** The term being analyzed must have two or more of OR-connected subterms.
** A single subterm might be a set of AND-connected sub-subterms.
** Examples of terms under analysis:
**
** (A) t1.x=t2.y OR t1.x=t2.z OR t1.y=15 OR t1.z=t3.a+5
** (B) x=expr1 OR expr2=x OR x=expr3
** (C) t1.x=t2.y OR (t1.x=t2.z AND t1.y=15)
** (D) x=expr1 OR (y>11 AND y<22 AND z LIKE '*hello*')
** (E) (p.a=1 AND q.b=2 AND r.c=3) OR (p.x=4 AND q.y=5 AND r.z=6)
** (F) x>A OR (x=A AND y>=B)
**
** CASE 1:
**
** If all subterms are of the form T.C=expr for some single column of C and
** a single table T (as shown in example B above) then create a new virtual
** term that is an equivalent IN expression. In other words, if the term
** being analyzed is:
**
** x = expr1 OR expr2 = x OR x = expr3
**
** then create a new virtual term like this:
**
** x IN (expr1,expr2,expr3)
**
** CASE 2:
**
** If there are exactly two disjuncts and one side has x>A and the other side
** has x=A (for the same x and A) then add a new virtual conjunct term to the
** WHERE clause of the form "x>=A". Example:
**
** x>A OR (x=A AND y>B) adds: x>=A
**
** The added conjunct can sometimes be helpful in query planning.
**
** CASE 3:
**
** If all subterms are indexable by a single table T, then set
**
** WhereTerm.eOperator = WO_OR
** WhereTerm.u.pOrInfo->indexable |= the cursor number for table T
**
** A subterm is "indexable" if it is of the form
** "T.C <op> <expr>" where C is any column of table T and
** <op> is one of "=", "<", "<=", ">", ">=", "IS NULL", or "IN".
** A subterm is also indexable if it is an AND of two or more
** subsubterms at least one of which is indexable. Indexable AND
** subterms have their eOperator set to WO_AND and they have
** u.pAndInfo set to a dynamically allocated WhereAndTerm object.
**
** From another point of view, "indexable" means that the subterm could
** potentially be used with an index if an appropriate index exists.
** This analysis does not consider whether or not the index exists; that
** is decided elsewhere. This analysis only looks at whether subterms
** appropriate for indexing exist.
**
** All examples A through E above satisfy case 3. But if a term
** also satisfies case 1 (such as B) we know that the optimizer will
** always prefer case 1, so in that case we pretend that case 3 is not
** satisfied.
**
** It might be the case that multiple tables are indexable. For example,
** (E) above is indexable on tables P, Q, and R.
**
** Terms that satisfy case 3 are candidates for lookup by using
** separate indices to find rowids for each subterm and composing
** the union of all rowids using a RowSet object. This is similar
** to "bitmap indices" in other database engines.
**
** OTHERWISE:
**
** If none of cases 1, 2, or 3 apply, then leave the eOperator set to
** zero. This term is not useful for search.
*/
static void exprAnalyzeOrTerm(
SrcList *pSrc, /* the FROM clause */
WhereClause *pWC, /* the complete WHERE clause */
int idxTerm /* Index of the OR-term to be analyzed */
){
WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
Parse *pParse = pWInfo->pParse; /* Parser context */
sqlite3 *db = pParse->db; /* Database connection */
WhereTerm *pTerm = &pWC->a[idxTerm]; /* The term to be analyzed */
Expr *pExpr = pTerm->pExpr; /* The expression of the term */
int i; /* Loop counters */
WhereClause *pOrWc; /* Breakup of pTerm into subterms */
WhereTerm *pOrTerm; /* A Sub-term within the pOrWc */
WhereOrInfo *pOrInfo; /* Additional information associated with pTerm */
Bitmask chngToIN; /* Tables that might satisfy case 1 */
Bitmask indexable; /* Tables that are indexable, satisfying case 2 */
/*
** Break the OR clause into its separate subterms. The subterms are
** stored in a WhereClause structure containing within the WhereOrInfo
** object that is attached to the original OR clause term.
*/
assert( (pTerm->wtFlags & (TERM_DYNAMIC|TERM_ORINFO|TERM_ANDINFO))==0 );
assert( pExpr->op==TK_OR );
pTerm->u.pOrInfo = pOrInfo = sqlite3DbMallocZero(db, sizeof(*pOrInfo));
if( pOrInfo==0 ) return;
pTerm->wtFlags |= TERM_ORINFO;
pOrWc = &pOrInfo->wc;
memset(pOrWc->aStatic, 0, sizeof(pOrWc->aStatic));
sqlite3WhereClauseInit(pOrWc, pWInfo);
sqlite3WhereSplit(pOrWc, pExpr, TK_OR);
sqlite3WhereExprAnalyze(pSrc, pOrWc);
if( db->mallocFailed ) return;
assert( pOrWc->nTerm>=2 );
/*
** Compute the set of tables that might satisfy cases 1 or 3.
*/
indexable = ~(Bitmask)0;
chngToIN = ~(Bitmask)0;
for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){
if( (pOrTerm->eOperator & WO_SINGLE)==0 ){
WhereAndInfo *pAndInfo;
assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 );
chngToIN = 0;
pAndInfo = sqlite3DbMallocRawNN(db, sizeof(*pAndInfo));
if( pAndInfo ){
WhereClause *pAndWC;
WhereTerm *pAndTerm;
int j;
Bitmask b = 0;
pOrTerm->u.pAndInfo = pAndInfo;
pOrTerm->wtFlags |= TERM_ANDINFO;
pOrTerm->eOperator = WO_AND;
pAndWC = &pAndInfo->wc;
memset(pAndWC->aStatic, 0, sizeof(pAndWC->aStatic));
sqlite3WhereClauseInit(pAndWC, pWC->pWInfo);
sqlite3WhereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
sqlite3WhereExprAnalyze(pSrc, pAndWC);
pAndWC->pOuter = pWC;
if( !db->mallocFailed ){
for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){
assert( pAndTerm->pExpr );
if( allowedOp(pAndTerm->pExpr->op)
|| pAndTerm->eOperator==WO_AUX
){
b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
}
}
}
indexable &= b;
}
}else if( pOrTerm->wtFlags & TERM_COPIED ){
/* Skip this term for now. We revisit it when we process the
** corresponding TERM_VIRTUAL term */
}else{
Bitmask b;
b = sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
if( pOrTerm->wtFlags & TERM_VIRTUAL ){
WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pOther->leftCursor);
}
indexable &= b;
if( (pOrTerm->eOperator & WO_EQ)==0 ){
chngToIN = 0;
}else{
chngToIN &= b;
}
}
}
/*
** Record the set of tables that satisfy case 3. The set might be
** empty.
*/
pOrInfo->indexable = indexable;
if( indexable ){
pTerm->eOperator = WO_OR;
pWC->hasOr = 1;
}else{
pTerm->eOperator = WO_OR;
}
/* For a two-way OR, attempt to implementation case 2.
*/
if( indexable && pOrWc->nTerm==2 ){
int iOne = 0;
WhereTerm *pOne;
while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){
int iTwo = 0;
WhereTerm *pTwo;
while( (pTwo = whereNthSubterm(&pOrWc->a[1],iTwo++))!=0 ){
whereCombineDisjuncts(pSrc, pWC, pOne, pTwo);
}
}
}
/*
** chngToIN holds a set of tables that *might* satisfy case 1. But
** we have to do some additional checking to see if case 1 really
** is satisfied.
**
** chngToIN will hold either 0, 1, or 2 bits. The 0-bit case means
** that there is no possibility of transforming the OR clause into an
** IN operator because one or more terms in the OR clause contain
** something other than == on a column in the single table. The 1-bit
** case means that every term of the OR clause is of the form
** "table.column=expr" for some single table. The one bit that is set
** will correspond to the common table. We still need to check to make
** sure the same column is used on all terms. The 2-bit case is when
** the all terms are of the form "table1.column=table2.column". It
** might be possible to form an IN operator with either table1.column
** or table2.column as the LHS if either is common to every term of
** the OR clause.
**
** Note that terms of the form "table.column1=table.column2" (the
** same table on both sizes of the ==) cannot be optimized.
*/
if( chngToIN ){
int okToChngToIN = 0; /* True if the conversion to IN is valid */
int iColumn = -1; /* Column index on lhs of IN operator */
int iCursor = -1; /* Table cursor common to all terms */
int j = 0; /* Loop counter */
/* Search for a table and column that appears on one side or the
** other of the == operator in every subterm. That table and column
** will be recorded in iCursor and iColumn. There might not be any
** such table and column. Set okToChngToIN if an appropriate table
** and column is found but leave okToChngToIN false if not found.
*/
for(j=0; j<2 && !okToChngToIN; j++){
Expr *pLeft = 0;
pOrTerm = pOrWc->a;
for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){
assert( pOrTerm->eOperator & WO_EQ );
pOrTerm->wtFlags &= ~TERM_OR_OK;
if( pOrTerm->leftCursor==iCursor ){
/* This is the 2-bit case and we are on the second iteration and
** current term is from the first iteration. So skip this term. */
assert( j==1 );
continue;
}
if( (chngToIN & sqlite3WhereGetMask(&pWInfo->sMaskSet,
pOrTerm->leftCursor))==0 ){
/* This term must be of the form t1.a==t2.b where t2 is in the
** chngToIN set but t1 is not. This term will be either preceded
** or follwed by an inverted copy (t2.b==t1.a). Skip this term
** and use its inversion. */
testcase( pOrTerm->wtFlags & TERM_COPIED );
testcase( pOrTerm->wtFlags & TERM_VIRTUAL );
assert( pOrTerm->wtFlags & (TERM_COPIED|TERM_VIRTUAL) );
continue;
}
iColumn = pOrTerm->u.x.leftColumn;
iCursor = pOrTerm->leftCursor;
pLeft = pOrTerm->pExpr->pLeft;
break;
}
if( i<0 ){
/* No candidate table+column was found. This can only occur
** on the second iteration */
assert( j==1 );
assert( IsPowerOfTwo(chngToIN) );
assert( chngToIN==sqlite3WhereGetMask(&pWInfo->sMaskSet, iCursor) );
break;
}
testcase( j==1 );
/* We have found a candidate table and column. Check to see if that
** table and column is common to every term in the OR clause */
okToChngToIN = 1;
for(; i>=0 && okToChngToIN; i--, pOrTerm++){
assert( pOrTerm->eOperator & WO_EQ );
if( pOrTerm->leftCursor!=iCursor ){
pOrTerm->wtFlags &= ~TERM_OR_OK;
}else if( pOrTerm->u.x.leftColumn!=iColumn || (iColumn==XN_EXPR
&& sqlite3ExprCompare(pParse, pOrTerm->pExpr->pLeft, pLeft, -1)
)){
okToChngToIN = 0;
}else{
int affLeft, affRight;
/* If the right-hand side is also a column, then the affinities
** of both right and left sides must be such that no type
** conversions are required on the right. (Ticket #2249)
*/
affRight = sqlite3ExprAffinity(pOrTerm->pExpr->pRight);
affLeft = sqlite3ExprAffinity(pOrTerm->pExpr->pLeft);
if( affRight!=0 && affRight!=affLeft ){
okToChngToIN = 0;
}else{
pOrTerm->wtFlags |= TERM_OR_OK;
}
}
}
}
/* At this point, okToChngToIN is true if original pTerm satisfies
** case 1. In that case, construct a new virtual term that is
** pTerm converted into an IN operator.
*/
if( okToChngToIN ){
Expr *pDup; /* A transient duplicate expression */
ExprList *pList = 0; /* The RHS of the IN operator */
Expr *pLeft = 0; /* The LHS of the IN operator */
Expr *pNew; /* The complete IN operator */
for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){
if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;
assert( pOrTerm->eOperator & WO_EQ );
assert( pOrTerm->leftCursor==iCursor );
assert( pOrTerm->u.x.leftColumn==iColumn );
pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
pLeft = pOrTerm->pExpr->pLeft;
}
assert( pLeft!=0 );
pDup = sqlite3ExprDup(db, pLeft, 0);
pNew = sqlite3PExpr(pParse, TK_IN, pDup, 0);
if( pNew ){
int idxNew;
transferJoinMarkings(pNew, pExpr);
assert( !ExprHasProperty(pNew, EP_xIsSelect) );
pNew->x.pList = pList;
idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
testcase( idxNew==0 );
exprAnalyze(pSrc, pWC, idxNew);
/* pTerm = &pWC->a[idxTerm]; // would be needed if pTerm where used again */
markTermAsChild(pWC, idxNew, idxTerm);
}else{
sqlite3ExprListDelete(db, pList);
}
}
}
}
#endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */
/*
** We already know that pExpr is a binary operator where both operands are
** column references. This routine checks to see if pExpr is an equivalence
** relation:
** 1. The SQLITE_Transitive optimization must be enabled
** 2. Must be either an == or an IS operator
** 3. Not originating in the ON clause of an OUTER JOIN
** 4. The affinities of A and B must be compatible
** 5a. Both operands use the same collating sequence OR
** 5b. The overall collating sequence is BINARY
** If this routine returns TRUE, that means that the RHS can be substituted
** for the LHS anyplace else in the WHERE clause where the LHS column occurs.
** This is an optimization. No harm comes from returning 0. But if 1 is
** returned when it should not be, then incorrect answers might result.
*/
static int termIsEquivalence(Parse *pParse, Expr *pExpr){
char aff1, aff2;
CollSeq *pColl;
if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;
if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;
if( ExprHasProperty(pExpr, EP_FromJoin) ) return 0;
aff1 = sqlite3ExprAffinity(pExpr->pLeft);
aff2 = sqlite3ExprAffinity(pExpr->pRight);
if( aff1!=aff2
&& (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))
){
return 0;
}
pColl = sqlite3ExprCompareCollSeq(pParse, pExpr);
if( sqlite3IsBinary(pColl) ) return 1;
return sqlite3ExprCollSeqMatch(pParse, pExpr->pLeft, pExpr->pRight);
}
/*
** Recursively walk the expressions of a SELECT statement and generate
** a bitmask indicating which tables are used in that expression
** tree.
*/
static Bitmask exprSelectUsage(WhereMaskSet *pMaskSet, Select *pS){
Bitmask mask = 0;
while( pS ){
SrcList *pSrc = pS->pSrc;
mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pEList);
mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pGroupBy);
mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pOrderBy);
mask |= sqlite3WhereExprUsage(pMaskSet, pS->pWhere);
mask |= sqlite3WhereExprUsage(pMaskSet, pS->pHaving);
if( ALWAYS(pSrc!=0) ){
int i;
for(i=0; i<pSrc->nSrc; i++){
mask |= exprSelectUsage(pMaskSet, pSrc->a[i].pSelect);
mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].pOn);
if( pSrc->a[i].fg.isTabFunc ){
mask |= sqlite3WhereExprListUsage(pMaskSet, pSrc->a[i].u1.pFuncArg);
}
}
}
pS = pS->pPrior;
}
return mask;
}
/*
** Expression pExpr is one operand of a comparison operator that might
** be useful for indexing. This routine checks to see if pExpr appears
** in any index. Return TRUE (1) if pExpr is an indexed term and return
** FALSE (0) if not. If TRUE is returned, also set aiCurCol[0] to the cursor
** number of the table that is indexed and aiCurCol[1] to the column number
** of the column that is indexed, or XN_EXPR (-2) if an expression is being
** indexed.
**
** If pExpr is a TK_COLUMN column reference, then this routine always returns
** true even if that particular column is not indexed, because the column
** might be added to an automatic index later.
*/
static SQLITE_NOINLINE int exprMightBeIndexed2(
SrcList *pFrom, /* The FROM clause */
Bitmask mPrereq, /* Bitmask of FROM clause terms referenced by pExpr */
int *aiCurCol, /* Write the referenced table cursor and column here */
Expr *pExpr /* An operand of a comparison operator */
){
Index *pIdx;
int i;
int iCur;
for(i=0; mPrereq>1; i++, mPrereq>>=1){}
iCur = pFrom->a[i].iCursor;
for(pIdx=pFrom->a[i].pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( pIdx->aColExpr==0 ) continue;
for(i=0; i<pIdx->nKeyCol; i++){
if( pIdx->aiColumn[i]!=XN_EXPR ) continue;
if( sqlite3ExprCompareSkip(pExpr, pIdx->aColExpr->a[i].pExpr, iCur)==0 ){
aiCurCol[0] = iCur;
aiCurCol[1] = XN_EXPR;
return 1;
}
}
}
return 0;
}
static int exprMightBeIndexed(
SrcList *pFrom, /* The FROM clause */
Bitmask mPrereq, /* Bitmask of FROM clause terms referenced by pExpr */
int *aiCurCol, /* Write the referenced table cursor & column here */
Expr *pExpr, /* An operand of a comparison operator */
int op /* The specific comparison operator */
){
/* If this expression is a vector to the left or right of a
** inequality constraint (>, <, >= or <=), perform the processing
** on the first element of the vector. */
assert( TK_GT+1==TK_LE && TK_GT+2==TK_LT && TK_GT+3==TK_GE );
assert( TK_IS<TK_GE && TK_ISNULL<TK_GE && TK_IN<TK_GE );
assert( op<=TK_GE );
if( pExpr->op==TK_VECTOR && (op>=TK_GT && ALWAYS(op<=TK_GE)) ){
pExpr = pExpr->x.pList->a[0].pExpr;
}
if( pExpr->op==TK_COLUMN ){
aiCurCol[0] = pExpr->iTable;
aiCurCol[1] = pExpr->iColumn;
return 1;
}
if( mPrereq==0 ) return 0; /* No table references */
if( (mPrereq&(mPrereq-1))!=0 ) return 0; /* Refs more than one table */
return exprMightBeIndexed2(pFrom,mPrereq,aiCurCol,pExpr);
}
/*
** The input to this routine is an WhereTerm structure with only the
** "pExpr" field filled in. The job of this routine is to analyze the
** subexpression and populate all the other fields of the WhereTerm
** structure.
**
** If the expression is of the form "<expr> <op> X" it gets commuted
** to the standard form of "X <op> <expr>".
**
** If the expression is of the form "X <op> Y" where both X and Y are
** columns, then the original expression is unchanged and a new virtual
** term of the form "Y <op> X" is added to the WHERE clause and
** analyzed separately. The original term is marked with TERM_COPIED
** and the new term is marked with TERM_DYNAMIC (because it's pExpr
** needs to be freed with the WhereClause) and TERM_VIRTUAL (because it
** is a commuted copy of a prior term.) The original term has nChild=1
** and the copy has idxParent set to the index of the original term.
*/
static void exprAnalyze(
SrcList *pSrc, /* the FROM clause */
WhereClause *pWC, /* the WHERE clause */
int idxTerm /* Index of the term to be analyzed */
){
WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
WhereTerm *pTerm; /* The term to be analyzed */
WhereMaskSet *pMaskSet; /* Set of table index masks */
Expr *pExpr; /* The expression to be analyzed */
Bitmask prereqLeft; /* Prerequesites of the pExpr->pLeft */
Bitmask prereqAll; /* Prerequesites of pExpr */
Bitmask extraRight = 0; /* Extra dependencies on LEFT JOIN */
Expr *pStr1 = 0; /* RHS of LIKE/GLOB operator */
int isComplete = 0; /* RHS of LIKE/GLOB ends with wildcard */
int noCase = 0; /* uppercase equivalent to lowercase */
int op; /* Top-level operator. pExpr->op */
Parse *pParse = pWInfo->pParse; /* Parsing context */
sqlite3 *db = pParse->db; /* Database connection */
unsigned char eOp2 = 0; /* op2 value for LIKE/REGEXP/GLOB */
int nLeft; /* Number of elements on left side vector */
if( db->mallocFailed ){
return;
}
pTerm = &pWC->a[idxTerm];
pMaskSet = &pWInfo->sMaskSet;
pExpr = pTerm->pExpr;
assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft);
op = pExpr->op;
if( op==TK_IN ){
assert( pExpr->pRight==0 );
if( sqlite3ExprCheckIN(pParse, pExpr) ) return;
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect);
}else{
pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList);
}
}else if( op==TK_ISNULL ){
pTerm->prereqRight = 0;
}else{
pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight);
}
pMaskSet->bVarSelect = 0;
prereqAll = sqlite3WhereExprUsageNN(pMaskSet, pExpr);
if( pMaskSet->bVarSelect ) pTerm->wtFlags |= TERM_VARSELECT;
if( ExprHasProperty(pExpr, EP_FromJoin) ){
Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);
prereqAll |= x;
extraRight = x-1; /* ON clause terms may not be used with an index
** on left table of a LEFT JOIN. Ticket #3015 */
if( (prereqAll>>1)>=x ){
sqlite3ErrorMsg(pParse, "ON clause references tables to its right");
return;
}
}
pTerm->prereqAll = prereqAll;
pTerm->leftCursor = -1;
pTerm->iParent = -1;
pTerm->eOperator = 0;
if( allowedOp(op) ){
int aiCurCol[2];
Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft);
Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight);
u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV;
if( pTerm->u.x.iField>0 ){
assert( op==TK_IN );
assert( pLeft->op==TK_VECTOR );
pLeft = pLeft->x.pList->a[pTerm->u.x.iField-1].pExpr;
}
if( exprMightBeIndexed(pSrc, prereqLeft, aiCurCol, pLeft, op) ){
pTerm->leftCursor = aiCurCol[0];
pTerm->u.x.leftColumn = aiCurCol[1];
pTerm->eOperator = operatorMask(op) & opMask;
}
if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;
if( pRight
&& exprMightBeIndexed(pSrc, pTerm->prereqRight, aiCurCol, pRight, op)
){
WhereTerm *pNew;
Expr *pDup;
u16 eExtraOp = 0; /* Extra bits for pNew->eOperator */
assert( pTerm->u.x.iField==0 );
if( pTerm->leftCursor>=0 ){
int idxNew;
pDup = sqlite3ExprDup(db, pExpr, 0);
if( db->mallocFailed ){
sqlite3ExprDelete(db, pDup);
return;
}
idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC);
if( idxNew==0 ) return;
pNew = &pWC->a[idxNew];
markTermAsChild(pWC, idxNew, idxTerm);
if( op==TK_IS ) pNew->wtFlags |= TERM_IS;
pTerm = &pWC->a[idxTerm];
pTerm->wtFlags |= TERM_COPIED;
if( termIsEquivalence(pParse, pDup) ){
pTerm->eOperator |= WO_EQUIV;
eExtraOp = WO_EQUIV;
}
}else{
pDup = pExpr;
pNew = pTerm;
}
pNew->wtFlags |= exprCommute(pParse, pDup);
pNew->leftCursor = aiCurCol[0];
pNew->u.x.leftColumn = aiCurCol[1];
testcase( (prereqLeft | extraRight) != prereqLeft );
pNew->prereqRight = prereqLeft | extraRight;
pNew->prereqAll = prereqAll;
pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
}
}
#ifndef SQLITE_OMIT_BETWEEN_OPTIMIZATION
/* If a term is the BETWEEN operator, create two new virtual terms
** that define the range that the BETWEEN implements. For example:
**
** a BETWEEN b AND c
**
** is converted into:
**
** (a BETWEEN b AND c) AND (a>=b) AND (a<=c)
**
** The two new terms are added onto the end of the WhereClause object.
** The new terms are "dynamic" and are children of the original BETWEEN
** term. That means that if the BETWEEN term is coded, the children are
** skipped. Or, if the children are satisfied by an index, the original
** BETWEEN term is skipped.
*/
else if( pExpr->op==TK_BETWEEN && pWC->op==TK_AND ){
ExprList *pList = pExpr->x.pList;
int i;
static const u8 ops[] = {TK_GE, TK_LE};
assert( pList!=0 );
assert( pList->nExpr==2 );
for(i=0; i<2; i++){
Expr *pNewExpr;
int idxNew;
pNewExpr = sqlite3PExpr(pParse, ops[i],
sqlite3ExprDup(db, pExpr->pLeft, 0),
sqlite3ExprDup(db, pList->a[i].pExpr, 0));
transferJoinMarkings(pNewExpr, pExpr);
idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
testcase( idxNew==0 );
exprAnalyze(pSrc, pWC, idxNew);
pTerm = &pWC->a[idxTerm];
markTermAsChild(pWC, idxNew, idxTerm);
}
}
#endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */
#if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
/* Analyze a term that is composed of two or more subterms connected by
** an OR operator.
*/
else if( pExpr->op==TK_OR ){
assert( pWC->op==TK_AND );
exprAnalyzeOrTerm(pSrc, pWC, idxTerm);
pTerm = &pWC->a[idxTerm];
}
#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
#ifndef SQLITE_OMIT_LIKE_OPTIMIZATION
/* Add constraints to reduce the search space on a LIKE or GLOB
** operator.
**
** A like pattern of the form "x LIKE 'aBc%'" is changed into constraints
**
** x>='ABC' AND x<'abd' AND x LIKE 'aBc%'
**
** The last character of the prefix "abc" is incremented to form the
** termination condition "abd". If case is not significant (the default
** for LIKE) then the lower-bound is made all uppercase and the upper-
** bound is made all lowercase so that the bounds also work when comparing
** BLOBs.
*/
if( pWC->op==TK_AND
&& isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)
){
Expr *pLeft; /* LHS of LIKE/GLOB operator */
Expr *pStr2; /* Copy of pStr1 - RHS of LIKE/GLOB operator */
Expr *pNewExpr1;
Expr *pNewExpr2;
int idxNew1;
int idxNew2;
const char *zCollSeqName; /* Name of collating sequence */
const u16 wtFlags = TERM_LIKEOPT | TERM_VIRTUAL | TERM_DYNAMIC;
pLeft = pExpr->x.pList->a[1].pExpr;
pStr2 = sqlite3ExprDup(db, pStr1, 0);
/* Convert the lower bound to upper-case and the upper bound to
** lower-case (upper-case is less than lower-case in ASCII) so that
** the range constraints also work for BLOBs
*/
if( noCase && !pParse->db->mallocFailed ){
int i;
char c;
pTerm->wtFlags |= TERM_LIKE;
for(i=0; (c = pStr1->u.zToken[i])!=0; i++){
pStr1->u.zToken[i] = sqlite3Toupper(c);
pStr2->u.zToken[i] = sqlite3Tolower(c);
}
}
if( !db->mallocFailed ){
u8 c, *pC; /* Last character before the first wildcard */
pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
c = *pC;
if( noCase ){
/* The point is to increment the last character before the first
** wildcard. But if we increment '@', that will push it into the
** alphabetic range where case conversions will mess up the
** inequality. To avoid this, make sure to also run the full
** LIKE on all candidate expressions by clearing the isComplete flag
*/
if( c=='A'-1 ) isComplete = 0;
c = sqlite3UpperToLower[c];
}
*pC = c + 1;
}
zCollSeqName = noCase ? "NOCASE" : sqlite3StrBINARY;
pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
pNewExpr1 = sqlite3PExpr(pParse, TK_GE,
sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName),
pStr1);
transferJoinMarkings(pNewExpr1, pExpr);
idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags);
testcase( idxNew1==0 );
exprAnalyze(pSrc, pWC, idxNew1);
pNewExpr2 = sqlite3ExprDup(db, pLeft, 0);
pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
sqlite3ExprAddCollateString(pParse,pNewExpr2,zCollSeqName),
pStr2);
transferJoinMarkings(pNewExpr2, pExpr);
idxNew2 = whereClauseInsert(pWC, pNewExpr2, wtFlags);
testcase( idxNew2==0 );
exprAnalyze(pSrc, pWC, idxNew2);
pTerm = &pWC->a[idxTerm];
if( isComplete ){
markTermAsChild(pWC, idxNew1, idxTerm);
markTermAsChild(pWC, idxNew2, idxTerm);
}
}
#endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Add a WO_AUX auxiliary term to the constraint set if the
** current expression is of the form "column OP expr" where OP
** is an operator that gets passed into virtual tables but which is
** not normally optimized for ordinary tables. In other words, OP
** is one of MATCH, LIKE, GLOB, REGEXP, !=, IS, IS NOT, or NOT NULL.
** This information is used by the xBestIndex methods of
** virtual tables. The native query optimizer does not attempt
** to do anything with MATCH functions.
*/
if( pWC->op==TK_AND ){
Expr *pRight = 0, *pLeft = 0;
int res = isAuxiliaryVtabOperator(db, pExpr, &eOp2, &pLeft, &pRight);
while( res-- > 0 ){
int idxNew;
WhereTerm *pNewTerm;
Bitmask prereqColumn, prereqExpr;
prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);
prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft);
if( (prereqExpr & prereqColumn)==0 ){
Expr *pNewExpr;
pNewExpr = sqlite3PExpr(pParse, TK_MATCH,
0, sqlite3ExprDup(db, pRight, 0));
if( ExprHasProperty(pExpr, EP_FromJoin) && pNewExpr ){
ExprSetProperty(pNewExpr, EP_FromJoin);
pNewExpr->iRightJoinTable = pExpr->iRightJoinTable;
}
idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
testcase( idxNew==0 );
pNewTerm = &pWC->a[idxNew];
pNewTerm->prereqRight = prereqExpr;
pNewTerm->leftCursor = pLeft->iTable;
pNewTerm->u.x.leftColumn = pLeft->iColumn;
pNewTerm->eOperator = WO_AUX;
pNewTerm->eMatchOp = eOp2;
markTermAsChild(pWC, idxNew, idxTerm);
pTerm = &pWC->a[idxTerm];
pTerm->wtFlags |= TERM_COPIED;
pNewTerm->prereqAll = pTerm->prereqAll;
}
SWAP(Expr*, pLeft, pRight);
}
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
/* If there is a vector == or IS term - e.g. "(a, b) == (?, ?)" - create
** new terms for each component comparison - "a = ?" and "b = ?". The
** new terms completely replace the original vector comparison, which is
** no longer used.
**
** This is only required if at least one side of the comparison operation
** is not a sub-select. */
if( pWC->op==TK_AND
&& (pExpr->op==TK_EQ || pExpr->op==TK_IS)
&& (nLeft = sqlite3ExprVectorSize(pExpr->pLeft))>1
&& sqlite3ExprVectorSize(pExpr->pRight)==nLeft
&& ( (pExpr->pLeft->flags & EP_xIsSelect)==0
|| (pExpr->pRight->flags & EP_xIsSelect)==0)
){
int i;
for(i=0; i<nLeft; i++){
int idxNew;
Expr *pNew;
Expr *pLeft = sqlite3ExprForVectorField(pParse, pExpr->pLeft, i);
Expr *pRight = sqlite3ExprForVectorField(pParse, pExpr->pRight, i);
pNew = sqlite3PExpr(pParse, pExpr->op, pLeft, pRight);
transferJoinMarkings(pNew, pExpr);
idxNew = whereClauseInsert(pWC, pNew, TERM_DYNAMIC);
exprAnalyze(pSrc, pWC, idxNew);
}
pTerm = &pWC->a[idxTerm];
pTerm->wtFlags |= TERM_CODED|TERM_VIRTUAL; /* Disable the original */
pTerm->eOperator = 0;
}
/* If there is a vector IN term - e.g. "(a, b) IN (SELECT ...)" - create
** a virtual term for each vector component. The expression object
** used by each such virtual term is pExpr (the full vector IN(...)
** expression). The WhereTerm.u.x.iField variable identifies the index within
** the vector on the LHS that the virtual term represents.
**
** This only works if the RHS is a simple SELECT (not a compound) that does
** not use window functions.
*/
if( pWC->op==TK_AND && pExpr->op==TK_IN && pTerm->u.x.iField==0
&& pExpr->pLeft->op==TK_VECTOR
&& pExpr->x.pSelect->pPrior==0
#ifndef SQLITE_OMIT_WINDOWFUNC
&& pExpr->x.pSelect->pWin==0
#endif
){
int i;
for(i=0; i<sqlite3ExprVectorSize(pExpr->pLeft); i++){
int idxNew;
idxNew = whereClauseInsert(pWC, pExpr, TERM_VIRTUAL);
pWC->a[idxNew].u.x.iField = i+1;
exprAnalyze(pSrc, pWC, idxNew);
markTermAsChild(pWC, idxNew, idxTerm);
}
}
#ifdef SQLITE_ENABLE_STAT4
/* When sqlite_stat4 histogram data is available an operator of the
** form "x IS NOT NULL" can sometimes be evaluated more efficiently
** as "x>NULL" if x is not an INTEGER PRIMARY KEY. So construct a
** virtual term of that form.
**
** Note that the virtual term must be tagged with TERM_VNULL.
*/
if( pExpr->op==TK_NOTNULL
&& pExpr->pLeft->op==TK_COLUMN
&& pExpr->pLeft->iColumn>=0
&& !ExprHasProperty(pExpr, EP_FromJoin)
&& OptimizationEnabled(db, SQLITE_Stat4)
){
Expr *pNewExpr;
Expr *pLeft = pExpr->pLeft;
int idxNew;
WhereTerm *pNewTerm;
pNewExpr = sqlite3PExpr(pParse, TK_GT,
sqlite3ExprDup(db, pLeft, 0),
sqlite3ExprAlloc(db, TK_NULL, 0, 0));
idxNew = whereClauseInsert(pWC, pNewExpr,
TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL);
if( idxNew ){
pNewTerm = &pWC->a[idxNew];
pNewTerm->prereqRight = 0;
pNewTerm->leftCursor = pLeft->iTable;
pNewTerm->u.x.leftColumn = pLeft->iColumn;
pNewTerm->eOperator = WO_GT;
markTermAsChild(pWC, idxNew, idxTerm);
pTerm = &pWC->a[idxTerm];
pTerm->wtFlags |= TERM_COPIED;
pNewTerm->prereqAll = pTerm->prereqAll;
}
}
#endif /* SQLITE_ENABLE_STAT4 */
/* Prevent ON clause terms of a LEFT JOIN from being used to drive
** an index for tables to the left of the join.
*/
testcase( pTerm!=&pWC->a[idxTerm] );
pTerm = &pWC->a[idxTerm];
pTerm->prereqRight |= extraRight;
}
/***************************************************************************
** Routines with file scope above. Interface to the rest of the where.c
** subsystem follows.
***************************************************************************/
/*
** This routine identifies subexpressions in the WHERE clause where
** each subexpression is separated by the AND operator or some other
** operator specified in the op parameter. The WhereClause structure
** is filled with pointers to subexpressions. For example:
**
** WHERE a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22)
** \________/ \_______________/ \________________/
** slot[0] slot[1] slot[2]
**
** The original WHERE clause in pExpr is unaltered. All this routine
** does is make slot[] entries point to substructure within pExpr.
**
** In the previous sentence and in the diagram, "slot[]" refers to
** the WhereClause.a[] array. The slot[] array grows as needed to contain
** all terms of the WHERE clause.
*/
SQLITE_PRIVATE void sqlite3WhereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
Expr *pE2 = sqlite3ExprSkipCollateAndLikely(pExpr);
pWC->op = op;
assert( pE2!=0 || pExpr==0 );
if( pE2==0 ) return;
if( pE2->op!=op ){
whereClauseInsert(pWC, pExpr, 0);
}else{
sqlite3WhereSplit(pWC, pE2->pLeft, op);
sqlite3WhereSplit(pWC, pE2->pRight, op);
}
}
/*
** Initialize a preallocated WhereClause structure.
*/
SQLITE_PRIVATE void sqlite3WhereClauseInit(
WhereClause *pWC, /* The WhereClause to be initialized */
WhereInfo *pWInfo /* The WHERE processing context */
){
pWC->pWInfo = pWInfo;
pWC->hasOr = 0;
pWC->pOuter = 0;
pWC->nTerm = 0;
pWC->nSlot = ArraySize(pWC->aStatic);
pWC->a = pWC->aStatic;
}
/*
** Deallocate a WhereClause structure. The WhereClause structure
** itself is not freed. This routine is the inverse of
** sqlite3WhereClauseInit().
*/
SQLITE_PRIVATE void sqlite3WhereClauseClear(WhereClause *pWC){
int i;
WhereTerm *a;
sqlite3 *db = pWC->pWInfo->pParse->db;
for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
if( a->wtFlags & TERM_DYNAMIC ){
sqlite3ExprDelete(db, a->pExpr);
}
if( a->wtFlags & TERM_ORINFO ){
whereOrInfoDelete(db, a->u.pOrInfo);
}else if( a->wtFlags & TERM_ANDINFO ){
whereAndInfoDelete(db, a->u.pAndInfo);
}
}
if( pWC->a!=pWC->aStatic ){
sqlite3DbFree(db, pWC->a);
}
}
/*
** These routines walk (recursively) an expression tree and generate
** a bitmask indicating which tables are used in that expression
** tree.
*/
SQLITE_PRIVATE Bitmask sqlite3WhereExprUsageNN(WhereMaskSet *pMaskSet, Expr *p){
Bitmask mask;
if( p->op==TK_COLUMN && !ExprHasProperty(p, EP_FixedCol) ){
return sqlite3WhereGetMask(pMaskSet, p->iTable);
}else if( ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
assert( p->op!=TK_IF_NULL_ROW );
return 0;
}
mask = (p->op==TK_IF_NULL_ROW) ? sqlite3WhereGetMask(pMaskSet, p->iTable) : 0;
if( p->pLeft ) mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pLeft);
if( p->pRight ){
mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pRight);
assert( p->x.pList==0 );
}else if( ExprHasProperty(p, EP_xIsSelect) ){
if( ExprHasProperty(p, EP_VarSelect) ) pMaskSet->bVarSelect = 1;
mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
}else if( p->x.pList ){
mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
}
#ifndef SQLITE_OMIT_WINDOWFUNC
if( (p->op==TK_FUNCTION || p->op==TK_AGG_FUNCTION) && p->y.pWin ){
mask |= sqlite3WhereExprListUsage(pMaskSet, p->y.pWin->pPartition);
mask |= sqlite3WhereExprListUsage(pMaskSet, p->y.pWin->pOrderBy);
mask |= sqlite3WhereExprUsage(pMaskSet, p->y.pWin->pFilter);
}
#endif
return mask;
}
SQLITE_PRIVATE Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
return p ? sqlite3WhereExprUsageNN(pMaskSet,p) : 0;
}
SQLITE_PRIVATE Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){
int i;
Bitmask mask = 0;
if( pList ){
for(i=0; i<pList->nExpr; i++){
mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);
}
}
return mask;
}
/*
** Call exprAnalyze on all terms in a WHERE clause.
**
** Note that exprAnalyze() might add new virtual terms onto the
** end of the WHERE clause. We do not want to analyze these new
** virtual terms, so start analyzing at the end and work forward
** so that the added virtual terms are never processed.
*/
SQLITE_PRIVATE void sqlite3WhereExprAnalyze(
SrcList *pTabList, /* the FROM clause */
WhereClause *pWC /* the WHERE clause to be analyzed */
){
int i;
for(i=pWC->nTerm-1; i>=0; i--){
exprAnalyze(pTabList, pWC, i);
}
}
/*
** For table-valued-functions, transform the function arguments into
** new WHERE clause terms.
**
** Each function argument translates into an equality constraint against
** a HIDDEN column in the table.
*/
SQLITE_PRIVATE void sqlite3WhereTabFuncArgs(
Parse *pParse, /* Parsing context */
struct SrcList_item *pItem, /* The FROM clause term to process */
WhereClause *pWC /* Xfer function arguments to here */
){
Table *pTab;
int j, k;
ExprList *pArgs;
Expr *pColRef;
Expr *pTerm;
if( pItem->fg.isTabFunc==0 ) return;
pTab = pItem->pTab;
assert( pTab!=0 );
pArgs = pItem->u1.pFuncArg;
if( pArgs==0 ) return;
for(j=k=0; j<pArgs->nExpr; j++){
Expr *pRhs;
while( k<pTab->nCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;}
if( k>=pTab->nCol ){
sqlite3ErrorMsg(pParse, "too many arguments on %s() - max %d",
pTab->zName, j);
return;
}
pColRef = sqlite3ExprAlloc(pParse->db, TK_COLUMN, 0, 0);
if( pColRef==0 ) return;
pColRef->iTable = pItem->iCursor;
pColRef->iColumn = k++;
pColRef->y.pTab = pTab;
pRhs = sqlite3PExpr(pParse, TK_UPLUS,
sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0);
pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef, pRhs);
if( pItem->fg.jointype & JT_LEFT ){
sqlite3SetJoinExpr(pTerm, pItem->iCursor);
}
whereClauseInsert(pWC, pTerm, TERM_DYNAMIC);
}
}
/************** End of whereexpr.c *******************************************/
/************** Begin file where.c *******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements. This module is responsible for
** generating the code that loops through a table looking for applicable
** rows. Indices are selected and used to speed the search when doing
** so is applicable. Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
*/
/* #include "sqliteInt.h" */
/* #include "whereInt.h" */
/*
** Extra information appended to the end of sqlite3_index_info but not
** visible to the xBestIndex function, at least not directly. The
** sqlite3_vtab_collation() interface knows how to reach it, however.
**
** This object is not an API and can be changed from one release to the
** next. As long as allocateIndexInfo() and sqlite3_vtab_collation()
** agree on the structure, all will be well.
*/
typedef struct HiddenIndexInfo HiddenIndexInfo;
struct HiddenIndexInfo {
WhereClause *pWC; /* The Where clause being analyzed */
Parse *pParse; /* The parsing context */
};
/* Forward declaration of methods */
static int whereLoopResize(sqlite3*, WhereLoop*, int);
/* Test variable that can be set to enable WHERE tracing */
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
/***/ int sqlite3WhereTrace = 0;
#endif
/*
** Return the estimated number of output rows from a WHERE clause
*/
SQLITE_PRIVATE LogEst sqlite3WhereOutputRowCount(WhereInfo *pWInfo){
return pWInfo->nRowOut;
}
/*
** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this
** WHERE clause returns outputs for DISTINCT processing.
*/
SQLITE_PRIVATE int sqlite3WhereIsDistinct(WhereInfo *pWInfo){
return pWInfo->eDistinct;
}
/*
** Return the number of ORDER BY terms that are satisfied by the
** WHERE clause. A return of 0 means that the output must be
** completely sorted. A return equal to the number of ORDER BY
** terms means that no sorting is needed at all. A return that
** is positive but less than the number of ORDER BY terms means that
** block sorting is required.
*/
SQLITE_PRIVATE int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
return pWInfo->nOBSat;
}
/*
** In the ORDER BY LIMIT optimization, if the inner-most loop is known
** to emit rows in increasing order, and if the last row emitted by the
** inner-most loop did not fit within the sorter, then we can skip all
** subsequent rows for the current iteration of the inner loop (because they
** will not fit in the sorter either) and continue with the second inner
** loop - the loop immediately outside the inner-most.
**
** When a row does not fit in the sorter (because the sorter already
** holds LIMIT+OFFSET rows that are smaller), then a jump is made to the
** label returned by this function.
**
** If the ORDER BY LIMIT optimization applies, the jump destination should
** be the continuation for the second-inner-most loop. If the ORDER BY
** LIMIT optimization does not apply, then the jump destination should
** be the continuation for the inner-most loop.
**
** It is always safe for this routine to return the continuation of the
** inner-most loop, in the sense that a correct answer will result.
** Returning the continuation the second inner loop is an optimization
** that might make the code run a little faster, but should not change
** the final answer.
*/
SQLITE_PRIVATE int sqlite3WhereOrderByLimitOptLabel(WhereInfo *pWInfo){
WhereLevel *pInner;
if( !pWInfo->bOrderedInnerLoop ){
/* The ORDER BY LIMIT optimization does not apply. Jump to the
** continuation of the inner-most loop. */
return pWInfo->iContinue;
}
pInner = &pWInfo->a[pWInfo->nLevel-1];
assert( pInner->addrNxt!=0 );
return pInner->addrNxt;
}
/*
** Return the VDBE address or label to jump to in order to continue
** immediately with the next row of a WHERE clause.
*/
SQLITE_PRIVATE int sqlite3WhereContinueLabel(WhereInfo *pWInfo){
assert( pWInfo->iContinue!=0 );
return pWInfo->iContinue;
}
/*
** Return the VDBE address or label to jump to in order to break
** out of a WHERE loop.
*/
SQLITE_PRIVATE int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
return pWInfo->iBreak;
}
/*
** Return ONEPASS_OFF (0) if an UPDATE or DELETE statement is unable to
** operate directly on the rowids returned by a WHERE clause. Return
** ONEPASS_SINGLE (1) if the statement can operation directly because only
** a single row is to be changed. Return ONEPASS_MULTI (2) if the one-pass
** optimization can be used on multiple
**
** If the ONEPASS optimization is used (if this routine returns true)
** then also write the indices of open cursors used by ONEPASS
** into aiCur[0] and aiCur[1]. iaCur[0] gets the cursor of the data
** table and iaCur[1] gets the cursor used by an auxiliary index.
** Either value may be -1, indicating that cursor is not used.
** Any cursors returned will have been opened for writing.
**
** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is
** unable to use the ONEPASS optimization.
*/
SQLITE_PRIVATE int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){
memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2);
#ifdef WHERETRACE_ENABLED
if( sqlite3WhereTrace && pWInfo->eOnePass!=ONEPASS_OFF ){
sqlite3DebugPrintf("%s cursors: %d %d\n",
pWInfo->eOnePass==ONEPASS_SINGLE ? "ONEPASS_SINGLE" : "ONEPASS_MULTI",
aiCur[0], aiCur[1]);
}
#endif
return pWInfo->eOnePass;
}
/*
** Return TRUE if the WHERE loop uses the OP_DeferredSeek opcode to move
** the data cursor to the row selected by the index cursor.
*/
SQLITE_PRIVATE int sqlite3WhereUsesDeferredSeek(WhereInfo *pWInfo){
return pWInfo->bDeferredSeek;
}
/*
** Move the content of pSrc into pDest
*/
static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
pDest->n = pSrc->n;
memcpy(pDest->a, pSrc->a, pDest->n*sizeof(pDest->a[0]));
}
/*
** Try to insert a new prerequisite/cost entry into the WhereOrSet pSet.
**
** The new entry might overwrite an existing entry, or it might be
** appended, or it might be discarded. Do whatever is the right thing
** so that pSet keeps the N_OR_COST best entries seen so far.
*/
static int whereOrInsert(
WhereOrSet *pSet, /* The WhereOrSet to be updated */
Bitmask prereq, /* Prerequisites of the new entry */
LogEst rRun, /* Run-cost of the new entry */
LogEst nOut /* Number of outputs for the new entry */
){
u16 i;
WhereOrCost *p;
for(i=pSet->n, p=pSet->a; i>0; i--, p++){
if( rRun<=p->rRun && (prereq & p->prereq)==prereq ){
goto whereOrInsert_done;
}
if( p->rRun<=rRun && (p->prereq & prereq)==p->prereq ){
return 0;
}
}
if( pSet->n<N_OR_COST ){
p = &pSet->a[pSet->n++];
p->nOut = nOut;
}else{
p = pSet->a;
for(i=1; i<pSet->n; i++){
if( p->rRun>pSet->a[i].rRun ) p = pSet->a + i;
}
if( p->rRun<=rRun ) return 0;
}
whereOrInsert_done:
p->prereq = prereq;
p->rRun = rRun;
if( p->nOut>nOut ) p->nOut = nOut;
return 1;
}
/*
** Return the bitmask for the given cursor number. Return 0 if
** iCursor is not in the set.
*/
SQLITE_PRIVATE Bitmask sqlite3WhereGetMask(WhereMaskSet *pMaskSet, int iCursor){
int i;
assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
for(i=0; i<pMaskSet->n; i++){
if( pMaskSet->ix[i]==iCursor ){
return MASKBIT(i);
}
}
return 0;
}
/*
** Create a new mask for cursor iCursor.
**
** There is one cursor per table in the FROM clause. The number of
** tables in the FROM clause is limited by a test early in the
** sqlite3WhereBegin() routine. So we know that the pMaskSet->ix[]
** array will never overflow.
*/
static void createMask(WhereMaskSet *pMaskSet, int iCursor){
assert( pMaskSet->n < ArraySize(pMaskSet->ix) );
pMaskSet->ix[pMaskSet->n++] = iCursor;
}
/*
** If the right-hand branch of the expression is a TK_COLUMN, then return
** a pointer to the right-hand branch. Otherwise, return NULL.
*/
static Expr *whereRightSubexprIsColumn(Expr *p){
p = sqlite3ExprSkipCollateAndLikely(p->pRight);
if( ALWAYS(p!=0) && p->op==TK_COLUMN ) return p;
return 0;
}
/*
** Advance to the next WhereTerm that matches according to the criteria
** established when the pScan object was initialized by whereScanInit().
** Return NULL if there are no more matching WhereTerms.
*/
static WhereTerm *whereScanNext(WhereScan *pScan){
int iCur; /* The cursor on the LHS of the term */
i16 iColumn; /* The column on the LHS of the term. -1 for IPK */
Expr *pX; /* An expression being tested */
WhereClause *pWC; /* Shorthand for pScan->pWC */
WhereTerm *pTerm; /* The term being tested */
int k = pScan->k; /* Where to start scanning */
assert( pScan->iEquiv<=pScan->nEquiv );
pWC = pScan->pWC;
while(1){
iColumn = pScan->aiColumn[pScan->iEquiv-1];
iCur = pScan->aiCur[pScan->iEquiv-1];
assert( pWC!=0 );
do{
for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
if( pTerm->leftCursor==iCur
&& pTerm->u.x.leftColumn==iColumn
&& (iColumn!=XN_EXPR
|| sqlite3ExprCompareSkip(pTerm->pExpr->pLeft,
pScan->pIdxExpr,iCur)==0)
&& (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
){
if( (pTerm->eOperator & WO_EQUIV)!=0
&& pScan->nEquiv<ArraySize(pScan->aiCur)
&& (pX = whereRightSubexprIsColumn(pTerm->pExpr))!=0
){
int j;
for(j=0; j<pScan->nEquiv; j++){
if( pScan->aiCur[j]==pX->iTable
&& pScan->aiColumn[j]==pX->iColumn ){
break;
}
}
if( j==pScan->nEquiv ){
pScan->aiCur[j] = pX->iTable;
pScan->aiColumn[j] = pX->iColumn;
pScan->nEquiv++;
}
}
if( (pTerm->eOperator & pScan->opMask)!=0 ){
/* Verify the affinity and collating sequence match */
if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){
CollSeq *pColl;
Parse *pParse = pWC->pWInfo->pParse;
pX = pTerm->pExpr;
if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){
continue;
}
assert(pX->pLeft);
pColl = sqlite3ExprCompareCollSeq(pParse, pX);
if( pColl==0 ) pColl = pParse->db->pDfltColl;
if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){
continue;
}
}
if( (pTerm->eOperator & (WO_EQ|WO_IS))!=0
&& (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
&& pX->iTable==pScan->aiCur[0]
&& pX->iColumn==pScan->aiColumn[0]
){
testcase( pTerm->eOperator & WO_IS );
continue;
}
pScan->pWC = pWC;
pScan->k = k+1;
return pTerm;
}
}
}
pWC = pWC->pOuter;
k = 0;
}while( pWC!=0 );
if( pScan->iEquiv>=pScan->nEquiv ) break;
pWC = pScan->pOrigWC;
k = 0;
pScan->iEquiv++;
}
return 0;
}
/*
** This is whereScanInit() for the case of an index on an expression.
** It is factored out into a separate tail-recursion subroutine so that
** the normal whereScanInit() routine, which is a high-runner, does not
** need to push registers onto the stack as part of its prologue.
*/
static SQLITE_NOINLINE WhereTerm *whereScanInitIndexExpr(WhereScan *pScan){
pScan->idxaff = sqlite3ExprAffinity(pScan->pIdxExpr);
return whereScanNext(pScan);
}
/*
** Initialize a WHERE clause scanner object. Return a pointer to the
** first match. Return NULL if there are no matches.
**
** The scanner will be searching the WHERE clause pWC. It will look
** for terms of the form "X <op> <expr>" where X is column iColumn of table
** iCur. Or if pIdx!=0 then X is column iColumn of index pIdx. pIdx
** must be one of the indexes of table iCur.
**
** The <op> must be one of the operators described by opMask.
**
** If the search is for X and the WHERE clause contains terms of the
** form X=Y then this routine might also return terms of the form
** "Y <op> <expr>". The number of levels of transitivity is limited,
** but is enough to handle most commonly occurring SQL statements.
**
** If X is not the INTEGER PRIMARY KEY then X must be compatible with
** index pIdx.
*/
static WhereTerm *whereScanInit(
WhereScan *pScan, /* The WhereScan object being initialized */
WhereClause *pWC, /* The WHERE clause to be scanned */
int iCur, /* Cursor to scan for */
int iColumn, /* Column to scan for */
u32 opMask, /* Operator(s) to scan for */
Index *pIdx /* Must be compatible with this index */
){
pScan->pOrigWC = pWC;
pScan->pWC = pWC;
pScan->pIdxExpr = 0;
pScan->idxaff = 0;
pScan->zCollName = 0;
pScan->opMask = opMask;
pScan->k = 0;
pScan->aiCur[0] = iCur;
pScan->nEquiv = 1;
pScan->iEquiv = 1;
if( pIdx ){
int j = iColumn;
iColumn = pIdx->aiColumn[j];
if( iColumn==XN_EXPR ){
pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
pScan->zCollName = pIdx->azColl[j];
pScan->aiColumn[0] = XN_EXPR;
return whereScanInitIndexExpr(pScan);
}else if( iColumn==pIdx->pTable->iPKey ){
iColumn = XN_ROWID;
}else if( iColumn>=0 ){
pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
pScan->zCollName = pIdx->azColl[j];
}
}else if( iColumn==XN_EXPR ){
return 0;
}
pScan->aiColumn[0] = iColumn;
return whereScanNext(pScan);
}
/*
** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
** where X is a reference to the iColumn of table iCur or of index pIdx
** if pIdx!=0 and <op> is one of the WO_xx operator codes specified by
** the op parameter. Return a pointer to the term. Return 0 if not found.
**
** If pIdx!=0 then it must be one of the indexes of table iCur.
** Search for terms matching the iColumn-th column of pIdx
** rather than the iColumn-th column of table iCur.
**
** The term returned might by Y=<expr> if there is another constraint in
** the WHERE clause that specifies that X=Y. Any such constraints will be
** identified by the WO_EQUIV bit in the pTerm->eOperator field. The
** aiCur[]/iaColumn[] arrays hold X and all its equivalents. There are 11
** slots in aiCur[]/aiColumn[] so that means we can look for X plus up to 10
** other equivalent values. Hence a search for X will return <expr> if X=A1
** and A1=A2 and A2=A3 and ... and A9=A10 and A10=<expr>.
**
** If there are multiple terms in the WHERE clause of the form "X <op> <expr>"
** then try for the one with no dependencies on <expr> - in other words where
** <expr> is a constant expression of some kind. Only return entries of
** the form "X <op> Y" where Y is a column in another table if no terms of
** the form "X <op> <const-expr>" exist. If no terms with a constant RHS
** exist, try to return a term that does not use WO_EQUIV.
*/
SQLITE_PRIVATE WhereTerm *sqlite3WhereFindTerm(
WhereClause *pWC, /* The WHERE clause to be searched */
int iCur, /* Cursor number of LHS */
int iColumn, /* Column number of LHS */
Bitmask notReady, /* RHS must not overlap with this mask */
u32 op, /* Mask of WO_xx values describing operator */
Index *pIdx /* Must be compatible with this index, if not NULL */
){
WhereTerm *pResult = 0;
WhereTerm *p;
WhereScan scan;
p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx);
op &= WO_EQ|WO_IS;
while( p ){
if( (p->prereqRight & notReady)==0 ){
if( p->prereqRight==0 && (p->eOperator&op)!=0 ){
testcase( p->eOperator & WO_IS );
return p;
}
if( pResult==0 ) pResult = p;
}
p = whereScanNext(&scan);
}
return pResult;
}
/*
** This function searches pList for an entry that matches the iCol-th column
** of index pIdx.
**
** If such an expression is found, its index in pList->a[] is returned. If
** no expression is found, -1 is returned.
*/
static int findIndexCol(
Parse *pParse, /* Parse context */
ExprList *pList, /* Expression list to search */
int iBase, /* Cursor for table associated with pIdx */
Index *pIdx, /* Index to match column of */
int iCol /* Column of index to match */
){
int i;
const char *zColl = pIdx->azColl[iCol];
for(i=0; i<pList->nExpr; i++){
Expr *p = sqlite3ExprSkipCollateAndLikely(pList->a[i].pExpr);
if( ALWAYS(p!=0)
&& p->op==TK_COLUMN
&& p->iColumn==pIdx->aiColumn[iCol]
&& p->iTable==iBase
){
CollSeq *pColl = sqlite3ExprNNCollSeq(pParse, pList->a[i].pExpr);
if( 0==sqlite3StrICmp(pColl->zName, zColl) ){
return i;
}
}
}
return -1;
}
/*
** Return TRUE if the iCol-th column of index pIdx is NOT NULL
*/
static int indexColumnNotNull(Index *pIdx, int iCol){
int j;
assert( pIdx!=0 );
assert( iCol>=0 && iCol<pIdx->nColumn );
j = pIdx->aiColumn[iCol];
if( j>=0 ){
return pIdx->pTable->aCol[j].notNull;
}else if( j==(-1) ){
return 1;
}else{
assert( j==(-2) );
return 0; /* Assume an indexed expression can always yield a NULL */
}
}
/*
** Return true if the DISTINCT expression-list passed as the third argument
** is redundant.
**
** A DISTINCT list is redundant if any subset of the columns in the
** DISTINCT list are collectively unique and individually non-null.
*/
static int isDistinctRedundant(
Parse *pParse, /* Parsing context */
SrcList *pTabList, /* The FROM clause */
WhereClause *pWC, /* The WHERE clause */
ExprList *pDistinct /* The result set that needs to be DISTINCT */
){
Table *pTab;
Index *pIdx;
int i;
int iBase;
/* If there is more than one table or sub-select in the FROM clause of
** this query, then it will not be possible to show that the DISTINCT
** clause is redundant. */
if( pTabList->nSrc!=1 ) return 0;
iBase = pTabList->a[0].iCursor;
pTab = pTabList->a[0].pTab;
/* If any of the expressions is an IPK column on table iBase, then return
** true. Note: The (p->iTable==iBase) part of this test may be false if the
** current SELECT is a correlated sub-query.
*/
for(i=0; i<pDistinct->nExpr; i++){
Expr *p = sqlite3ExprSkipCollateAndLikely(pDistinct->a[i].pExpr);
if( NEVER(p==0) ) continue;
if( p->op==TK_COLUMN && p->iTable==iBase && p->iColumn<0 ) return 1;
}
/* Loop through all indices on the table, checking each to see if it makes
** the DISTINCT qualifier redundant. It does so if:
**
** 1. The index is itself UNIQUE, and
**
** 2. All of the columns in the index are either part of the pDistinct
** list, or else the WHERE clause contains a term of the form "col=X",
** where X is a constant value. The collation sequences of the
** comparison and select-list expressions must match those of the index.
**
** 3. All of those index columns for which the WHERE clause does not
** contain a "col=X" term are subject to a NOT NULL constraint.
*/
for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
if( !IsUniqueIndex(pIdx) ) continue;
for(i=0; i<pIdx->nKeyCol; i++){
if( 0==sqlite3WhereFindTerm(pWC, iBase, i, ~(Bitmask)0, WO_EQ, pIdx) ){
if( findIndexCol(pParse, pDistinct, iBase, pIdx, i)<0 ) break;
if( indexColumnNotNull(pIdx, i)==0 ) break;
}
}
if( i==pIdx->nKeyCol ){
/* This index implies that the DISTINCT qualifier is redundant. */
return 1;
}
}
return 0;
}
/*
** Estimate the logarithm of the input value to base 2.
*/
static LogEst estLog(LogEst N){
return N<=10 ? 0 : sqlite3LogEst(N) - 33;
}
/*
** Convert OP_Column opcodes to OP_Copy in previously generated code.
**
** This routine runs over generated VDBE code and translates OP_Column
** opcodes into OP_Copy when the table is being accessed via co-routine
** instead of via table lookup.
**
** If the iAutoidxCur is not zero, then any OP_Rowid instructions on
** cursor iTabCur are transformed into OP_Sequence opcode for the
** iAutoidxCur cursor, in order to generate unique rowids for the
** automatic index being generated.
*/
static void translateColumnToCopy(
Parse *pParse, /* Parsing context */
int iStart, /* Translate from this opcode to the end */
int iTabCur, /* OP_Column/OP_Rowid references to this table */
int iRegister, /* The first column is in this register */
int iAutoidxCur /* If non-zero, cursor of autoindex being generated */
){
Vdbe *v = pParse->pVdbe;
VdbeOp *pOp = sqlite3VdbeGetOp(v, iStart);
int iEnd = sqlite3VdbeCurrentAddr(v);
if( pParse->db->mallocFailed ) return;
for(; iStart<iEnd; iStart++, pOp++){
if( pOp->p1!=iTabCur ) continue;
if( pOp->opcode==OP_Column ){
pOp->opcode = OP_Copy;
pOp->p1 = pOp->p2 + iRegister;
pOp->p2 = pOp->p3;
pOp->p3 = 0;
}else if( pOp->opcode==OP_Rowid ){
if( iAutoidxCur ){
pOp->opcode = OP_Sequence;
pOp->p1 = iAutoidxCur;
}else{
pOp->opcode = OP_Null;
pOp->p1 = 0;
pOp->p3 = 0;
}
}
}
}
/*
** Two routines for printing the content of an sqlite3_index_info
** structure. Used for testing and debugging only. If neither
** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
** are no-ops.
*/
#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)
static void whereTraceIndexInfoInputs(sqlite3_index_info *p){
int i;
if( !sqlite3WhereTrace ) return;
for(i=0; i<p->nConstraint; i++){
sqlite3DebugPrintf(" constraint[%d]: col=%d termid=%d op=%d usabled=%d\n",
i,
p->aConstraint[i].iColumn,
p->aConstraint[i].iTermOffset,
p->aConstraint[i].op,
p->aConstraint[i].usable);
}
for(i=0; i<p->nOrderBy; i++){
sqlite3DebugPrintf(" orderby[%d]: col=%d desc=%d\n",
i,
p->aOrderBy[i].iColumn,
p->aOrderBy[i].desc);
}
}
static void whereTraceIndexInfoOutputs(sqlite3_index_info *p){
int i;
if( !sqlite3WhereTrace ) return;
for(i=0; i<p->nConstraint; i++){
sqlite3DebugPrintf(" usage[%d]: argvIdx=%d omit=%d\n",
i,
p->aConstraintUsage[i].argvIndex,
p->aConstraintUsage[i].omit);
}
sqlite3DebugPrintf(" idxNum=%d\n", p->idxNum);
sqlite3DebugPrintf(" idxStr=%s\n", p->idxStr);
sqlite3DebugPrintf(" orderByConsumed=%d\n", p->orderByConsumed);
sqlite3DebugPrintf(" estimatedCost=%g\n", p->estimatedCost);
sqlite3DebugPrintf(" estimatedRows=%lld\n", p->estimatedRows);
}
#else
#define whereTraceIndexInfoInputs(A)
#define whereTraceIndexInfoOutputs(A)
#endif
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*
** Return TRUE if the WHERE clause term pTerm is of a form where it
** could be used with an index to access pSrc, assuming an appropriate
** index existed.
*/
static int termCanDriveIndex(
WhereTerm *pTerm, /* WHERE clause term to check */
struct SrcList_item *pSrc, /* Table we are trying to access */
Bitmask notReady /* Tables in outer loops of the join */
){
char aff;
if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
if( (pTerm->eOperator & (WO_EQ|WO_IS))==0 ) return 0;
if( (pSrc->fg.jointype & JT_LEFT)
&& !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
&& (pTerm->eOperator & WO_IS)
){
/* Cannot use an IS term from the WHERE clause as an index driver for
** the RHS of a LEFT JOIN. Such a term can only be used if it is from
** the ON clause. */
return 0;
}
if( (pTerm->prereqRight & notReady)!=0 ) return 0;
if( pTerm->u.x.leftColumn<0 ) return 0;
aff = pSrc->pTab->aCol[pTerm->u.x.leftColumn].affinity;
if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
testcase( pTerm->pExpr->op==TK_IS );
return 1;
}
#endif
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*
** Generate code to construct the Index object for an automatic index
** and to set up the WhereLevel object pLevel so that the code generator
** makes use of the automatic index.
*/
static void constructAutomaticIndex(
Parse *pParse, /* The parsing context */
WhereClause *pWC, /* The WHERE clause */
struct SrcList_item *pSrc, /* The FROM clause term to get the next index */
Bitmask notReady, /* Mask of cursors that are not available */
WhereLevel *pLevel /* Write new index here */
){
int nKeyCol; /* Number of columns in the constructed index */
WhereTerm *pTerm; /* A single term of the WHERE clause */
WhereTerm *pWCEnd; /* End of pWC->a[] */
Index *pIdx; /* Object describing the transient index */
Vdbe *v; /* Prepared statement under construction */
int addrInit; /* Address of the initialization bypass jump */
Table *pTable; /* The table being indexed */
int addrTop; /* Top of the index fill loop */
int regRecord; /* Register holding an index record */
int n; /* Column counter */
int i; /* Loop counter */
int mxBitCol; /* Maximum column in pSrc->colUsed */
CollSeq *pColl; /* Collating sequence to on a column */
WhereLoop *pLoop; /* The Loop object */
char *zNotUsed; /* Extra space on the end of pIdx */
Bitmask idxCols; /* Bitmap of columns used for indexing */
Bitmask extraCols; /* Bitmap of additional columns */
u8 sentWarning = 0; /* True if a warnning has been issued */
Expr *pPartial = 0; /* Partial Index Expression */
int iContinue = 0; /* Jump here to skip excluded rows */
struct SrcList_item *pTabItem; /* FROM clause term being indexed */
int addrCounter = 0; /* Address where integer counter is initialized */
int regBase; /* Array of registers where record is assembled */
/* Generate code to skip over the creation and initialization of the
** transient index on 2nd and subsequent iterations of the loop. */
v = pParse->pVdbe;
assert( v!=0 );
addrInit = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
/* Count the number of columns that will be added to the index
** and used to match WHERE clause constraints */
nKeyCol = 0;
pTable = pSrc->pTab;
pWCEnd = &pWC->a[pWC->nTerm];
pLoop = pLevel->pWLoop;
idxCols = 0;
for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
Expr *pExpr = pTerm->pExpr;
assert( !ExprHasProperty(pExpr, EP_FromJoin) /* prereq always non-zero */
|| pExpr->iRightJoinTable!=pSrc->iCursor /* for the right-hand */
|| pLoop->prereq!=0 ); /* table of a LEFT JOIN */
if( pLoop->prereq==0
&& (pTerm->wtFlags & TERM_VIRTUAL)==0
&& !ExprHasProperty(pExpr, EP_FromJoin)
&& sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor) ){
pPartial = sqlite3ExprAnd(pParse, pPartial,
sqlite3ExprDup(pParse->db, pExpr, 0));
}
if( termCanDriveIndex(pTerm, pSrc, notReady) ){
int iCol = pTerm->u.x.leftColumn;
Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
testcase( iCol==BMS );
testcase( iCol==BMS-1 );
if( !sentWarning ){
sqlite3_log(SQLITE_WARNING_AUTOINDEX,
"automatic index on %s(%s)", pTable->zName,
pTable->aCol[iCol].zName);
sentWarning = 1;
}
if( (idxCols & cMask)==0 ){
if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ){
goto end_auto_index_create;
}
pLoop->aLTerm[nKeyCol++] = pTerm;
idxCols |= cMask;
}
}
}
assert( nKeyCol>0 );
pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol;
pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED
| WHERE_AUTO_INDEX;
/* Count the number of additional columns needed to create a
** covering index. A "covering index" is an index that contains all
** columns that are needed by the query. With a covering index, the
** original table never needs to be accessed. Automatic indices must
** be a covering index because the index will not be updated if the
** original table changes and the index and table cannot both be used
** if they go out of sync.
*/
extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
mxBitCol = MIN(BMS-1,pTable->nCol);
testcase( pTable->nCol==BMS-1 );
testcase( pTable->nCol==BMS-2 );
for(i=0; i<mxBitCol; i++){
if( extraCols & MASKBIT(i) ) nKeyCol++;
}
if( pSrc->colUsed & MASKBIT(BMS-1) ){
nKeyCol += pTable->nCol - BMS + 1;
}
/* Construct the Index object to describe this index */
pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed);
if( pIdx==0 ) goto end_auto_index_create;
pLoop->u.btree.pIndex = pIdx;
pIdx->zName = "auto-index";
pIdx->pTable = pTable;
n = 0;
idxCols = 0;
for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
if( termCanDriveIndex(pTerm, pSrc, notReady) ){
int iCol = pTerm->u.x.leftColumn;
Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
testcase( iCol==BMS-1 );
testcase( iCol==BMS );
if( (idxCols & cMask)==0 ){
Expr *pX = pTerm->pExpr;
idxCols |= cMask;
pIdx->aiColumn[n] = pTerm->u.x.leftColumn;
pColl = sqlite3ExprCompareCollSeq(pParse, pX);
assert( pColl!=0 || pParse->nErr>0 ); /* TH3 collate01.800 */
pIdx->azColl[n] = pColl ? pColl->zName : sqlite3StrBINARY;
n++;
}
}
}
assert( (u32)n==pLoop->u.btree.nEq );
/* Add additional columns needed to make the automatic index into
** a covering index */
for(i=0; i<mxBitCol; i++){
if( extraCols & MASKBIT(i) ){
pIdx->aiColumn[n] = i;
pIdx->azColl[n] = sqlite3StrBINARY;
n++;
}
}
if( pSrc->colUsed & MASKBIT(BMS-1) ){
for(i=BMS-1; i<pTable->nCol; i++){
pIdx->aiColumn[n] = i;
pIdx->azColl[n] = sqlite3StrBINARY;
n++;
}
}
assert( n==nKeyCol );
pIdx->aiColumn[n] = XN_ROWID;
pIdx->azColl[n] = sqlite3StrBINARY;
/* Create the automatic index */
assert( pLevel->iIdxCur>=0 );
pLevel->iIdxCur = pParse->nTab++;
sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1);
sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
VdbeComment((v, "for %s", pTable->zName));
/* Fill the automatic index with content */
pTabItem = &pWC->pWInfo->pTabList->a[pLevel->iFrom];
if( pTabItem->fg.viaCoroutine ){
int regYield = pTabItem->regReturn;
addrCounter = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub);
addrTop = sqlite3VdbeAddOp1(v, OP_Yield, regYield);
VdbeCoverage(v);
VdbeComment((v, "next row of %s", pTabItem->pTab->zName));
}else{
addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v);
}
if( pPartial ){
iContinue = sqlite3VdbeMakeLabel(pParse);
sqlite3ExprIfFalse(pParse, pPartial, iContinue, SQLITE_JUMPIFNULL);
pLoop->wsFlags |= WHERE_PARTIALIDX;
}
regRecord = sqlite3GetTempReg(pParse);
regBase = sqlite3GenerateIndexKey(
pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0
);
sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
if( pPartial ) sqlite3VdbeResolveLabel(v, iContinue);
if( pTabItem->fg.viaCoroutine ){
sqlite3VdbeChangeP2(v, addrCounter, regBase+n);
testcase( pParse->db->mallocFailed );
assert( pLevel->iIdxCur>0 );
translateColumnToCopy(pParse, addrTop, pLevel->iTabCur,
pTabItem->regResult, pLevel->iIdxCur);
sqlite3VdbeGoto(v, addrTop);
pTabItem->fg.viaCoroutine = 0;
}else{
sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v);
sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX);
}
sqlite3VdbeJumpHere(v, addrTop);
sqlite3ReleaseTempReg(pParse, regRecord);
/* Jump here when skipping the initialization */
sqlite3VdbeJumpHere(v, addrInit);
end_auto_index_create:
sqlite3ExprDelete(pParse->db, pPartial);
}
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Allocate and populate an sqlite3_index_info structure. It is the
** responsibility of the caller to eventually release the structure
** by passing the pointer returned by this function to sqlite3_free().
*/
static sqlite3_index_info *allocateIndexInfo(
Parse *pParse, /* The parsing context */
WhereClause *pWC, /* The WHERE clause being analyzed */
Bitmask mUnusable, /* Ignore terms with these prereqs */
struct SrcList_item *pSrc, /* The FROM clause term that is the vtab */
ExprList *pOrderBy, /* The ORDER BY clause */
u16 *pmNoOmit /* Mask of terms not to omit */
){
int i, j;
int nTerm;
struct sqlite3_index_constraint *pIdxCons;
struct sqlite3_index_orderby *pIdxOrderBy;
struct sqlite3_index_constraint_usage *pUsage;
struct HiddenIndexInfo *pHidden;
WhereTerm *pTerm;
int nOrderBy;
sqlite3_index_info *pIdxInfo;
u16 mNoOmit = 0;
/* Count the number of possible WHERE clause constraints referring
** to this virtual table */
for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
if( pTerm->leftCursor != pSrc->iCursor ) continue;
if( pTerm->prereqRight & mUnusable ) continue;
assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
testcase( pTerm->eOperator & WO_IN );
testcase( pTerm->eOperator & WO_ISNULL );
testcase( pTerm->eOperator & WO_IS );
testcase( pTerm->eOperator & WO_ALL );
if( (pTerm->eOperator & ~(WO_EQUIV))==0 ) continue;
if( pTerm->wtFlags & TERM_VNULL ) continue;
assert( pTerm->u.x.leftColumn>=(-1) );
nTerm++;
}
/* If the ORDER BY clause contains only columns in the current
** virtual table then allocate space for the aOrderBy part of
** the sqlite3_index_info structure.
*/
nOrderBy = 0;
if( pOrderBy ){
int n = pOrderBy->nExpr;
for(i=0; i<n; i++){
Expr *pExpr = pOrderBy->a[i].pExpr;
if( pExpr->op!=TK_COLUMN || pExpr->iTable!=pSrc->iCursor ) break;
if( pOrderBy->a[i].sortFlags & KEYINFO_ORDER_BIGNULL ) break;
}
if( i==n){
nOrderBy = n;
}
}
/* Allocate the sqlite3_index_info structure
*/
pIdxInfo = sqlite3DbMallocZero(pParse->db, sizeof(*pIdxInfo)
+ (sizeof(*pIdxCons) + sizeof(*pUsage))*nTerm
+ sizeof(*pIdxOrderBy)*nOrderBy + sizeof(*pHidden) );
if( pIdxInfo==0 ){
sqlite3ErrorMsg(pParse, "out of memory");
return 0;
}
pHidden = (struct HiddenIndexInfo*)&pIdxInfo[1];
pIdxCons = (struct sqlite3_index_constraint*)&pHidden[1];
pIdxOrderBy = (struct sqlite3_index_orderby*)&pIdxCons[nTerm];
pUsage = (struct sqlite3_index_constraint_usage*)&pIdxOrderBy[nOrderBy];
pIdxInfo->nOrderBy = nOrderBy;
pIdxInfo->aConstraint = pIdxCons;
pIdxInfo->aOrderBy = pIdxOrderBy;
pIdxInfo->aConstraintUsage = pUsage;
pHidden->pWC = pWC;
pHidden->pParse = pParse;
for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
u16 op;
if( pTerm->leftCursor != pSrc->iCursor ) continue;
if( pTerm->prereqRight & mUnusable ) continue;
assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) );
testcase( pTerm->eOperator & WO_IN );
testcase( pTerm->eOperator & WO_IS );
testcase( pTerm->eOperator & WO_ISNULL );
testcase( pTerm->eOperator & WO_ALL );
if( (pTerm->eOperator & ~(WO_EQUIV))==0 ) continue;
if( pTerm->wtFlags & TERM_VNULL ) continue;
/* tag-20191211-002: WHERE-clause constraints are not useful to the
** right-hand table of a LEFT JOIN. See tag-20191211-001 for the
** equivalent restriction for ordinary tables. */
if( (pSrc->fg.jointype & JT_LEFT)!=0
&& !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
){
continue;
}
assert( pTerm->u.x.leftColumn>=(-1) );
pIdxCons[j].iColumn = pTerm->u.x.leftColumn;
pIdxCons[j].iTermOffset = i;
op = pTerm->eOperator & WO_ALL;
if( op==WO_IN ) op = WO_EQ;
if( op==WO_AUX ){
pIdxCons[j].op = pTerm->eMatchOp;
}else if( op & (WO_ISNULL|WO_IS) ){
if( op==WO_ISNULL ){
pIdxCons[j].op = SQLITE_INDEX_CONSTRAINT_ISNULL;
}else{
pIdxCons[j].op = SQLITE_INDEX_CONSTRAINT_IS;
}
}else{
pIdxCons[j].op = (u8)op;
/* The direct assignment in the previous line is possible only because
** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical. The
** following asserts verify this fact. */
assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ );
assert( WO_LT==SQLITE_INDEX_CONSTRAINT_LT );
assert( WO_LE==SQLITE_INDEX_CONSTRAINT_LE );
assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT );
assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE );
assert( pTerm->eOperator&(WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_AUX) );
if( op & (WO_LT|WO_LE|WO_GT|WO_GE)
&& sqlite3ExprIsVector(pTerm->pExpr->pRight)
){
testcase( j!=i );
if( j<16 ) mNoOmit |= (1 << j);
if( op==WO_LT ) pIdxCons[j].op = WO_LE;
if( op==WO_GT ) pIdxCons[j].op = WO_GE;
}
}
j++;
}
pIdxInfo->nConstraint = j;
for(i=0; i<nOrderBy; i++){
Expr *pExpr = pOrderBy->a[i].pExpr;
pIdxOrderBy[i].iColumn = pExpr->iColumn;
pIdxOrderBy[i].desc = pOrderBy->a[i].sortFlags & KEYINFO_ORDER_DESC;
}
*pmNoOmit = mNoOmit;
return pIdxInfo;
}
/*
** The table object reference passed as the second argument to this function
** must represent a virtual table. This function invokes the xBestIndex()
** method of the virtual table with the sqlite3_index_info object that
** comes in as the 3rd argument to this function.
**
** If an error occurs, pParse is populated with an error message and an
** appropriate error code is returned. A return of SQLITE_CONSTRAINT from
** xBestIndex is not considered an error. SQLITE_CONSTRAINT indicates that
** the current configuration of "unusable" flags in sqlite3_index_info can
** not result in a valid plan.
**
** Whether or not an error is returned, it is the responsibility of the
** caller to eventually free p->idxStr if p->needToFreeIdxStr indicates
** that this is required.
*/
static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
sqlite3_vtab *pVtab = sqlite3GetVTable(pParse->db, pTab)->pVtab;
int rc;
whereTraceIndexInfoInputs(p);
rc = pVtab->pModule->xBestIndex(pVtab, p);
whereTraceIndexInfoOutputs(p);
if( rc!=SQLITE_OK && rc!=SQLITE_CONSTRAINT ){
if( rc==SQLITE_NOMEM ){
sqlite3OomFault(pParse->db);
}else if( !pVtab->zErrMsg ){
sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc));
}else{
sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg);
}
}
sqlite3_free(pVtab->zErrMsg);
pVtab->zErrMsg = 0;
return rc;
}
#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
#ifdef SQLITE_ENABLE_STAT4
/*
** Estimate the location of a particular key among all keys in an
** index. Store the results in aStat as follows:
**
** aStat[0] Est. number of rows less than pRec
** aStat[1] Est. number of rows equal to pRec
**
** Return the index of the sample that is the smallest sample that
** is greater than or equal to pRec. Note that this index is not an index
** into the aSample[] array - it is an index into a virtual set of samples
** based on the contents of aSample[] and the number of fields in record
** pRec.
*/
static int whereKeyStats(
Parse *pParse, /* Database connection */
Index *pIdx, /* Index to consider domain of */
UnpackedRecord *pRec, /* Vector of values to consider */
int roundUp, /* Round up if true. Round down if false */
tRowcnt *aStat /* OUT: stats written here */
){
IndexSample *aSample = pIdx->aSample;
int iCol; /* Index of required stats in anEq[] etc. */
int i; /* Index of first sample >= pRec */
int iSample; /* Smallest sample larger than or equal to pRec */
int iMin = 0; /* Smallest sample not yet tested */
int iTest; /* Next sample to test */
int res; /* Result of comparison operation */
int nField; /* Number of fields in pRec */
tRowcnt iLower = 0; /* anLt[] + anEq[] of largest sample pRec is > */
#ifndef SQLITE_DEBUG
UNUSED_PARAMETER( pParse );
#endif
assert( pRec!=0 );
assert( pIdx->nSample>0 );
assert( pRec->nField>0 && pRec->nField<=pIdx->nSampleCol );
/* Do a binary search to find the first sample greater than or equal
** to pRec. If pRec contains a single field, the set of samples to search
** is simply the aSample[] array. If the samples in aSample[] contain more
** than one fields, all fields following the first are ignored.
**
** If pRec contains N fields, where N is more than one, then as well as the
** samples in aSample[] (truncated to N fields), the search also has to
** consider prefixes of those samples. For example, if the set of samples
** in aSample is:
**
** aSample[0] = (a, 5)
** aSample[1] = (a, 10)
** aSample[2] = (b, 5)
** aSample[3] = (c, 100)
** aSample[4] = (c, 105)
**
** Then the search space should ideally be the samples above and the
** unique prefixes [a], [b] and [c]. But since that is hard to organize,
** the code actually searches this set:
**
** 0: (a)
** 1: (a, 5)
** 2: (a, 10)
** 3: (a, 10)
** 4: (b)
** 5: (b, 5)
** 6: (c)
** 7: (c, 100)
** 8: (c, 105)
** 9: (c, 105)
**
** For each sample in the aSample[] array, N samples are present in the
** effective sample array. In the above, samples 0 and 1 are based on
** sample aSample[0]. Samples 2 and 3 on aSample[1] etc.
**
** Often, sample i of each block of N effective samples has (i+1) fields.
** Except, each sample may be extended to ensure that it is greater than or
** equal to the previous sample in the array. For example, in the above,
** sample 2 is the first sample of a block of N samples, so at first it
** appears that it should be 1 field in size. However, that would make it
** smaller than sample 1, so the binary search would not work. As a result,
** it is extended to two fields. The duplicates that this creates do not
** cause any problems.
*/
nField = pRec->nField;
iCol = 0;
iSample = pIdx->nSample * nField;
do{
int iSamp; /* Index in aSample[] of test sample */
int n; /* Number of fields in test sample */
iTest = (iMin+iSample)/2;
iSamp = iTest / nField;
if( iSamp>0 ){
/* The proposed effective sample is a prefix of sample aSample[iSamp].
** Specifically, the shortest prefix of at least (1 + iTest%nField)
** fields that is greater than the previous effective sample. */
for(n=(iTest % nField) + 1; n<nField; n++){
if( aSample[iSamp-1].anLt[n-1]!=aSample[iSamp].anLt[n-1] ) break;
}
}else{
n = iTest + 1;
}
pRec->nField = n;
res = sqlite3VdbeRecordCompare(aSample[iSamp].n, aSample[iSamp].p, pRec);
if( res<0 ){
iLower = aSample[iSamp].anLt[n-1] + aSample[iSamp].anEq[n-1];
iMin = iTest+1;
}else if( res==0 && n<nField ){
iLower = aSample[iSamp].anLt[n-1];
iMin = iTest+1;
res = -1;
}else{
iSample = iTest;
iCol = n-1;
}
}while( res && iMin<iSample );
i = iSample / nField;
#ifdef SQLITE_DEBUG
/* The following assert statements check that the binary search code
** above found the right answer. This block serves no purpose other
** than to invoke the asserts. */
if( pParse->db->mallocFailed==0 ){
if( res==0 ){
/* If (res==0) is true, then pRec must be equal to sample i. */
assert( i<pIdx->nSample );
assert( iCol==nField-1 );
pRec->nField = nField;
assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)
|| pParse->db->mallocFailed
);
}else{
/* Unless i==pIdx->nSample, indicating that pRec is larger than
** all samples in the aSample[] array, pRec must be smaller than the
** (iCol+1) field prefix of sample i. */
assert( i<=pIdx->nSample && i>=0 );
pRec->nField = iCol+1;
assert( i==pIdx->nSample
|| sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)>0
|| pParse->db->mallocFailed );
/* if i==0 and iCol==0, then record pRec is smaller than all samples
** in the aSample[] array. Otherwise, if (iCol>0) then pRec must
** be greater than or equal to the (iCol) field prefix of sample i.
** If (i>0), then pRec must also be greater than sample (i-1). */
if( iCol>0 ){
pRec->nField = iCol;
assert( sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec)<=0
|| pParse->db->mallocFailed );
}
if( i>0 ){
pRec->nField = nField;
assert( sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec)<0
|| pParse->db->mallocFailed );
}
}
}
#endif /* ifdef SQLITE_DEBUG */
if( res==0 ){
/* Record pRec is equal to sample i */
assert( iCol==nField-1 );
aStat[0] = aSample[i].anLt[iCol];
aStat[1] = aSample[i].anEq[iCol];
}else{
/* At this point, the (iCol+1) field prefix of aSample[i] is the first
** sample that is greater than pRec. Or, if i==pIdx->nSample then pRec
** is larger than all samples in the array. */
tRowcnt iUpper, iGap;
if( i>=pIdx->nSample ){
iUpper = sqlite3LogEstToInt(pIdx->aiRowLogEst[0]);
}else{
iUpper = aSample[i].anLt[iCol];
}
if( iLower>=iUpper ){
iGap = 0;
}else{
iGap = iUpper - iLower;
}
if( roundUp ){
iGap = (iGap*2)/3;
}else{
iGap = iGap/3;
}
aStat[0] = iLower + iGap;
aStat[1] = pIdx->aAvgEq[nField-1];
}
/* Restore the pRec->nField value before returning. */
pRec->nField = nField;
return i;
}
#endif /* SQLITE_ENABLE_STAT4 */
/*
** If it is not NULL, pTerm is a term that provides an upper or lower
** bound on a range scan. Without considering pTerm, it is estimated
** that the scan will visit nNew rows. This function returns the number
** estimated to be visited after taking pTerm into account.
**
** If the user explicitly specified a likelihood() value for this term,
** then the return value is the likelihood multiplied by the number of
** input rows. Otherwise, this function assumes that an "IS NOT NULL" term
** has a likelihood of 0.50, and any other term a likelihood of 0.25.
*/
static LogEst whereRangeAdjust(WhereTerm *pTerm, LogEst nNew){
LogEst nRet = nNew;
if( pTerm ){
if( pTerm->truthProb<=0 ){
nRet += pTerm->truthProb;
}else if( (pTerm->wtFlags & TERM_VNULL)==0 ){
nRet -= 20; assert( 20==sqlite3LogEst(4) );
}
}
return nRet;
}
#ifdef SQLITE_ENABLE_STAT4
/*
** Return the affinity for a single column of an index.
*/
SQLITE_PRIVATE char sqlite3IndexColumnAffinity(sqlite3 *db, Index *pIdx, int iCol){
assert( iCol>=0 && iCol<pIdx->nColumn );
if( !pIdx->zColAff ){
if( sqlite3IndexAffinityStr(db, pIdx)==0 ) return SQLITE_AFF_BLOB;
}
assert( pIdx->zColAff[iCol]!=0 );
return pIdx->zColAff[iCol];
}
#endif
#ifdef SQLITE_ENABLE_STAT4
/*
** This function is called to estimate the number of rows visited by a
** range-scan on a skip-scan index. For example:
**
** CREATE INDEX i1 ON t1(a, b, c);
** SELECT * FROM t1 WHERE a=? AND c BETWEEN ? AND ?;
**
** Value pLoop->nOut is currently set to the estimated number of rows
** visited for scanning (a=? AND b=?). This function reduces that estimate
** by some factor to account for the (c BETWEEN ? AND ?) expression based
** on the stat4 data for the index. this scan will be peformed multiple
** times (once for each (a,b) combination that matches a=?) is dealt with
** by the caller.
**
** It does this by scanning through all stat4 samples, comparing values
** extracted from pLower and pUpper with the corresponding column in each
** sample. If L and U are the number of samples found to be less than or
** equal to the values extracted from pLower and pUpper respectively, and
** N is the total number of samples, the pLoop->nOut value is adjusted
** as follows:
**
** nOut = nOut * ( min(U - L, 1) / N )
**
** If pLower is NULL, or a value cannot be extracted from the term, L is
** set to zero. If pUpper is NULL, or a value cannot be extracted from it,
** U is set to N.
**
** Normally, this function sets *pbDone to 1 before returning. However,
** if no value can be extracted from either pLower or pUpper (and so the
** estimate of the number of rows delivered remains unchanged), *pbDone
** is left as is.
**
** If an error occurs, an SQLite error code is returned. Otherwise,
** SQLITE_OK.
*/
static int whereRangeSkipScanEst(
Parse *pParse, /* Parsing & code generating context */
WhereTerm *pLower, /* Lower bound on the range. ex: "x>123" Might be NULL */
WhereTerm *pUpper, /* Upper bound on the range. ex: "x<455" Might be NULL */
WhereLoop *pLoop, /* Update the .nOut value of this loop */
int *pbDone /* Set to true if at least one expr. value extracted */
){
Index *p = pLoop->u.btree.pIndex;
int nEq = pLoop->u.btree.nEq;
sqlite3 *db = pParse->db;
int nLower = -1;
int nUpper = p->nSample+1;
int rc = SQLITE_OK;
u8 aff = sqlite3IndexColumnAffinity(db, p, nEq);
CollSeq *pColl;
sqlite3_value *p1 = 0; /* Value extracted from pLower */
sqlite3_value *p2 = 0; /* Value extracted from pUpper */
sqlite3_value *pVal = 0; /* Value extracted from record */
pColl = sqlite3LocateCollSeq(pParse, p->azColl[nEq]);
if( pLower ){
rc = sqlite3Stat4ValueFromExpr(pParse, pLower->pExpr->pRight, aff, &p1);
nLower = 0;
}
if( pUpper && rc==SQLITE_OK ){
rc = sqlite3Stat4ValueFromExpr(pParse, pUpper->pExpr->pRight, aff, &p2);
nUpper = p2 ? 0 : p->nSample;
}
if( p1 || p2 ){
int i;
int nDiff;
for(i=0; rc==SQLITE_OK && i<p->nSample; i++){
rc = sqlite3Stat4Column(db, p->aSample[i].p, p->aSample[i].n, nEq, &pVal);
if( rc==SQLITE_OK && p1 ){
int res = sqlite3MemCompare(p1, pVal, pColl);
if( res>=0 ) nLower++;
}
if( rc==SQLITE_OK && p2 ){
int res = sqlite3MemCompare(p2, pVal, pColl);
if( res>=0 ) nUpper++;
}
}
nDiff = (nUpper - nLower);
if( nDiff<=0 ) nDiff = 1;
/* If there is both an upper and lower bound specified, and the
** comparisons indicate that they are close together, use the fallback
** method (assume that the scan visits 1/64 of the rows) for estimating
** the number of rows visited. Otherwise, estimate the number of rows
** using the method described in the header comment for this function. */
if( nDiff!=1 || pUpper==0 || pLower==0 ){
int nAdjust = (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff));
pLoop->nOut -= nAdjust;
*pbDone = 1;
WHERETRACE(0x10, ("range skip-scan regions: %u..%u adjust=%d est=%d\n",
nLower, nUpper, nAdjust*-1, pLoop->nOut));
}
}else{
assert( *pbDone==0 );
}
sqlite3ValueFree(p1);
sqlite3ValueFree(p2);
sqlite3ValueFree(pVal);
return rc;
}
#endif /* SQLITE_ENABLE_STAT4 */
/*
** This function is used to estimate the number of rows that will be visited
** by scanning an index for a range of values. The range may have an upper
** bound, a lower bound, or both. The WHERE clause terms that set the upper
** and lower bounds are represented by pLower and pUpper respectively. For
** example, assuming that index p is on t1(a):
**
** ... FROM t1 WHERE a > ? AND a < ? ...
** |_____| |_____|
** | |
** pLower pUpper
**
** If either of the upper or lower bound is not present, then NULL is passed in
** place of the corresponding WhereTerm.
**
** The value in (pBuilder->pNew->u.btree.nEq) is the number of the index
** column subject to the range constraint. Or, equivalently, the number of
** equality constraints optimized by the proposed index scan. For example,
** assuming index p is on t1(a, b), and the SQL query is:
**
** ... FROM t1 WHERE a = ? AND b > ? AND b < ? ...
**
** then nEq is set to 1 (as the range restricted column, b, is the second
** left-most column of the index). Or, if the query is:
**
** ... FROM t1 WHERE a > ? AND a < ? ...
**
** then nEq is set to 0.
**
** When this function is called, *pnOut is set to the sqlite3LogEst() of the
** number of rows that the index scan is expected to visit without
** considering the range constraints. If nEq is 0, then *pnOut is the number of
** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced)
** to account for the range constraints pLower and pUpper.
**
** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be
** used, a single range inequality reduces the search space by a factor of 4.
** and a pair of constraints (x>? AND x<?) reduces the expected number of
** rows visited by a factor of 64.
*/
static int whereRangeScanEst(
Parse *pParse, /* Parsing & code generating context */
WhereLoopBuilder *pBuilder,
WhereTerm *pLower, /* Lower bound on the range. ex: "x>123" Might be NULL */
WhereTerm *pUpper, /* Upper bound on the range. ex: "x<455" Might be NULL */
WhereLoop *pLoop /* Modify the .nOut and maybe .rRun fields */
){
int rc = SQLITE_OK;
int nOut = pLoop->nOut;
LogEst nNew;
#ifdef SQLITE_ENABLE_STAT4
Index *p = pLoop->u.btree.pIndex;
int nEq = pLoop->u.btree.nEq;
if( p->nSample>0 && ALWAYS(nEq<p->nSampleCol)
&& OptimizationEnabled(pParse->db, SQLITE_Stat4)
){
if( nEq==pBuilder->nRecValid ){
UnpackedRecord *pRec = pBuilder->pRec;
tRowcnt a[2];
int nBtm = pLoop->u.btree.nBtm;
int nTop = pLoop->u.btree.nTop;
/* Variable iLower will be set to the estimate of the number of rows in
** the index that are less than the lower bound of the range query. The
** lower bound being the concatenation of $P and $L, where $P is the
** key-prefix formed by the nEq values matched against the nEq left-most
** columns of the index, and $L is the value in pLower.
**
** Or, if pLower is NULL or $L cannot be extracted from it (because it
** is not a simple variable or literal value), the lower bound of the
** range is $P. Due to a quirk in the way whereKeyStats() works, even
** if $L is available, whereKeyStats() is called for both ($P) and
** ($P:$L) and the larger of the two returned values is used.
**
** Similarly, iUpper is to be set to the estimate of the number of rows
** less than the upper bound of the range query. Where the upper bound
** is either ($P) or ($P:$U). Again, even if $U is available, both values
** of iUpper are requested of whereKeyStats() and the smaller used.
**
** The number of rows between the two bounds is then just iUpper-iLower.
*/
tRowcnt iLower; /* Rows less than the lower bound */
tRowcnt iUpper; /* Rows less than the upper bound */
int iLwrIdx = -2; /* aSample[] for the lower bound */
int iUprIdx = -1; /* aSample[] for the upper bound */
if( pRec ){
testcase( pRec->nField!=pBuilder->nRecValid );
pRec->nField = pBuilder->nRecValid;
}
/* Determine iLower and iUpper using ($P) only. */
if( nEq==0 ){
iLower = 0;
iUpper = p->nRowEst0;
}else{
/* Note: this call could be optimized away - since the same values must
** have been requested when testing key $P in whereEqualScanEst(). */
whereKeyStats(pParse, p, pRec, 0, a);
iLower = a[0];
iUpper = a[0] + a[1];
}
assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );
assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
assert( p->aSortOrder!=0 );
if( p->aSortOrder[nEq] ){
/* The roles of pLower and pUpper are swapped for a DESC index */
SWAP(WhereTerm*, pLower, pUpper);
SWAP(int, nBtm, nTop);
}
/* If possible, improve on the iLower estimate using ($P:$L). */
if( pLower ){
int n; /* Values extracted from pExpr */
Expr *pExpr = pLower->pExpr->pRight;
rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, nBtm, nEq, &n);
if( rc==SQLITE_OK && n ){
tRowcnt iNew;
u16 mask = WO_GT|WO_LE;
if( sqlite3ExprVectorSize(pExpr)>n ) mask = (WO_LE|WO_LT);
iLwrIdx = whereKeyStats(pParse, p, pRec, 0, a);
iNew = a[0] + ((pLower->eOperator & mask) ? a[1] : 0);
if( iNew>iLower ) iLower = iNew;
nOut--;
pLower = 0;
}
}
/* If possible, improve on the iUpper estimate using ($P:$U). */
if( pUpper ){
int n; /* Values extracted from pExpr */
Expr *pExpr = pUpper->pExpr->pRight;
rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, nTop, nEq, &n);
if( rc==SQLITE_OK && n ){
tRowcnt iNew;
u16 mask = WO_GT|WO_LE;
if( sqlite3ExprVectorSize(pExpr)>n ) mask = (WO_LE|WO_LT);
iUprIdx = whereKeyStats(pParse, p, pRec, 1, a);
iNew = a[0] + ((pUpper->eOperator & mask) ? a[1] : 0);
if( iNew<iUpper ) iUpper = iNew;
nOut--;
pUpper = 0;
}
}
pBuilder->pRec = pRec;
if( rc==SQLITE_OK ){
if( iUpper>iLower ){
nNew = sqlite3LogEst(iUpper - iLower);
/* TUNING: If both iUpper and iLower are derived from the same
** sample, then assume they are 4x more selective. This brings
** the estimated selectivity more in line with what it would be
** if estimated without the use of STAT4 tables. */
if( iLwrIdx==iUprIdx ) nNew -= 20; assert( 20==sqlite3LogEst(4) );
}else{
nNew = 10; assert( 10==sqlite3LogEst(2) );
}
if( nNew<nOut ){
nOut = nNew;
}
WHERETRACE(0x10, ("STAT4 range scan: %u..%u est=%d\n",
(u32)iLower, (u32)iUpper, nOut));
}
}else{
int bDone = 0;
rc = whereRangeSkipScanEst(pParse, pLower, pUpper, pLoop, &bDone);
if( bDone ) return rc;
}
}
#else
UNUSED_PARAMETER(pParse);
UNUSED_PARAMETER(pBuilder);
assert( pLower || pUpper );
#endif
assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 );
nNew = whereRangeAdjust(pLower, nOut);
nNew = whereRangeAdjust(pUpper, nNew);
/* TUNING: If there is both an upper and lower limit and neither limit
** has an application-defined likelihood(), assume the range is
** reduced by an additional 75%. This means that, by default, an open-ended
** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the
** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to
** match 1/64 of the index. */
if( pLower && pLower->truthProb>0 && pUpper && pUpper->truthProb>0 ){
nNew -= 20;
}
nOut -= (pLower!=0) + (pUpper!=0);
if( nNew<10 ) nNew = 10;
if( nNew<nOut ) nOut = nNew;
#if defined(WHERETRACE_ENABLED)
if( pLoop->nOut>nOut ){
WHERETRACE(0x10,("Range scan lowers nOut from %d to %d\n",
pLoop->nOut, nOut));
}
#endif
pLoop->nOut = (LogEst)nOut;
return rc;
}
#ifdef SQLITE_ENABLE_STAT4
/*
** Estimate the number of rows that will be returned based on
** an equality constraint x=VALUE and where that VALUE occurs in
** the histogram data. This only works when x is the left-most
** column of an index and sqlite_stat4 histogram data is available
** for that index. When pExpr==NULL that means the constraint is
** "x IS NULL" instead of "x=VALUE".
**
** Write the estimated row count into *pnRow and return SQLITE_OK.
** If unable to make an estimate, leave *pnRow unchanged and return
** non-zero.
**
** This routine can fail if it is unable to load a collating sequence
** required for string comparison, or if unable to allocate memory
** for a UTF conversion required for comparison. The error is stored
** in the pParse structure.
*/
static int whereEqualScanEst(
Parse *pParse, /* Parsing & code generating context */
WhereLoopBuilder *pBuilder,
Expr *pExpr, /* Expression for VALUE in the x=VALUE constraint */
tRowcnt *pnRow /* Write the revised row estimate here */
){
Index *p = pBuilder->pNew->u.btree.pIndex;
int nEq = pBuilder->pNew->u.btree.nEq;
UnpackedRecord *pRec = pBuilder->pRec;
int rc; /* Subfunction return code */
tRowcnt a[2]; /* Statistics */
int bOk;
assert( nEq>=1 );
assert( nEq<=p->nColumn );
assert( p->aSample!=0 );
assert( p->nSample>0 );
assert( pBuilder->nRecValid<nEq );
/* If values are not available for all fields of the index to the left
** of this one, no estimate can be made. Return SQLITE_NOTFOUND. */
if( pBuilder->nRecValid<(nEq-1) ){
return SQLITE_NOTFOUND;
}
/* This is an optimization only. The call to sqlite3Stat4ProbeSetValue()
** below would return the same value. */
if( nEq>=p->nColumn ){
*pnRow = 1;
return SQLITE_OK;
}
rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, 1, nEq-1, &bOk);
pBuilder->pRec = pRec;
if( rc!=SQLITE_OK ) return rc;
if( bOk==0 ) return SQLITE_NOTFOUND;
pBuilder->nRecValid = nEq;
whereKeyStats(pParse, p, pRec, 0, a);
WHERETRACE(0x10,("equality scan regions %s(%d): %d\n",
p->zName, nEq-1, (int)a[1]));
*pnRow = a[1];
return rc;
}
#endif /* SQLITE_ENABLE_STAT4 */
#ifdef SQLITE_ENABLE_STAT4
/*
** Estimate the number of rows that will be returned based on
** an IN constraint where the right-hand side of the IN operator
** is a list of values. Example:
**
** WHERE x IN (1,2,3,4)
**
** Write the estimated row count into *pnRow and return SQLITE_OK.
** If unable to make an estimate, leave *pnRow unchanged and return
** non-zero.
**
** This routine can fail if it is unable to load a collating sequence
** required for string comparison, or if unable to allocate memory
** for a UTF conversion required for comparison. The error is stored
** in the pParse structure.
*/
static int whereInScanEst(
Parse *pParse, /* Parsing & code generating context */
WhereLoopBuilder *pBuilder,
ExprList *pList, /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
tRowcnt *pnRow /* Write the revised row estimate here */
){
Index *p = pBuilder->pNew->u.btree.pIndex;
i64 nRow0 = sqlite3LogEstToInt(p->aiRowLogEst[0]);
int nRecValid = pBuilder->nRecValid;
int rc = SQLITE_OK; /* Subfunction return code */
tRowcnt nEst; /* Number of rows for a single term */
tRowcnt nRowEst = 0; /* New estimate of the number of rows */
int i; /* Loop counter */
assert( p->aSample!=0 );
for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){
nEst = nRow0;
rc = whereEqualScanEst(pParse, pBuilder, pList->a[i].pExpr, &nEst);
nRowEst += nEst;
pBuilder->nRecValid = nRecValid;
}
if( rc==SQLITE_OK ){
if( nRowEst > nRow0 ) nRowEst = nRow0;
*pnRow = nRowEst;
WHERETRACE(0x10,("IN row estimate: est=%d\n", nRowEst));
}
assert( pBuilder->nRecValid==nRecValid );
return rc;
}
#endif /* SQLITE_ENABLE_STAT4 */
#ifdef WHERETRACE_ENABLED
/*
** Print the content of a WhereTerm object
*/
SQLITE_PRIVATE void sqlite3WhereTermPrint(WhereTerm *pTerm, int iTerm){
if( pTerm==0 ){
sqlite3DebugPrintf("TERM-%-3d NULL\n", iTerm);
}else{
char zType[8];
char zLeft[50];
memcpy(zType, "....", 5);
if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V';
if( pTerm->eOperator & WO_EQUIV ) zType[1] = 'E';
if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L';
if( pTerm->wtFlags & TERM_CODED ) zType[3] = 'C';
if( pTerm->eOperator & WO_SINGLE ){
sqlite3_snprintf(sizeof(zLeft),zLeft,"left={%d:%d}",
pTerm->leftCursor, pTerm->u.x.leftColumn);
}else if( (pTerm->eOperator & WO_OR)!=0 && pTerm->u.pOrInfo!=0 ){
sqlite3_snprintf(sizeof(zLeft),zLeft,"indexable=0x%llx",
pTerm->u.pOrInfo->indexable);
}else{
sqlite3_snprintf(sizeof(zLeft),zLeft,"left=%d", pTerm->leftCursor);
}
sqlite3DebugPrintf(
"TERM-%-3d %p %s %-12s op=%03x wtFlags=%04x",
iTerm, pTerm, zType, zLeft, pTerm->eOperator, pTerm->wtFlags);
/* The 0x10000 .wheretrace flag causes extra information to be
** shown about each Term */
if( sqlite3WhereTrace & 0x10000 ){
sqlite3DebugPrintf(" prob=%-3d prereq=%llx,%llx",
pTerm->truthProb, (u64)pTerm->prereqAll, (u64)pTerm->prereqRight);
}
if( pTerm->u.x.iField ){
sqlite3DebugPrintf(" iField=%d", pTerm->u.x.iField);
}
if( pTerm->iParent>=0 ){
sqlite3DebugPrintf(" iParent=%d", pTerm->iParent);
}
sqlite3DebugPrintf("\n");
sqlite3TreeViewExpr(0, pTerm->pExpr, 0);
}
}
#endif
#ifdef WHERETRACE_ENABLED
/*
** Show the complete content of a WhereClause
*/
SQLITE_PRIVATE void sqlite3WhereClausePrint(WhereClause *pWC){
int i;
for(i=0; i<pWC->nTerm; i++){
sqlite3WhereTermPrint(&pWC->a[i], i);
}
}
#endif
#ifdef WHERETRACE_ENABLED
/*
** Print a WhereLoop object for debugging purposes
*/
SQLITE_PRIVATE void sqlite3WhereLoopPrint(WhereLoop *p, WhereClause *pWC){
WhereInfo *pWInfo = pWC->pWInfo;
int nb = 1+(pWInfo->pTabList->nSrc+3)/4;
struct SrcList_item *pItem = pWInfo->pTabList->a + p->iTab;
Table *pTab = pItem->pTab;
Bitmask mAll = (((Bitmask)1)<<(nb*4)) - 1;
sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
p->iTab, nb, p->maskSelf, nb, p->prereq & mAll);
sqlite3DebugPrintf(" %12s",
pItem->zAlias ? pItem->zAlias : pTab->zName);
if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
const char *zName;
if( p->u.btree.pIndex && (zName = p->u.btree.pIndex->zName)!=0 ){
if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){
int i = sqlite3Strlen30(zName) - 1;
while( zName[i]!='_' ) i--;
zName += i;
}
sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq);
}else{
sqlite3DebugPrintf("%20s","");
}
}else{
char *z;
if( p->u.vtab.idxStr ){
z = sqlite3_mprintf("(%d,\"%s\",%#x)",
p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);
}else{
z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
}
sqlite3DebugPrintf(" %-19s", z);
sqlite3_free(z);
}
if( p->wsFlags & WHERE_SKIPSCAN ){
sqlite3DebugPrintf(" f %05x %d-%d", p->wsFlags, p->nLTerm,p->nSkip);
}else{
sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm);
}
sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){
int i;
for(i=0; i<p->nLTerm; i++){
sqlite3WhereTermPrint(p->aLTerm[i], i);
}
}
}
#endif
/*
** Convert bulk memory into a valid WhereLoop that can be passed
** to whereLoopClear harmlessly.
*/
static void whereLoopInit(WhereLoop *p){
p->aLTerm = p->aLTermSpace;
p->nLTerm = 0;
p->nLSlot = ArraySize(p->aLTermSpace);
p->wsFlags = 0;
}
/*
** Clear the WhereLoop.u union. Leave WhereLoop.pLTerm intact.
*/
static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){
if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_AUTO_INDEX) ){
if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){
sqlite3_free(p->u.vtab.idxStr);
p->u.vtab.needFree = 0;
p->u.vtab.idxStr = 0;
}else if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 && p->u.btree.pIndex!=0 ){
sqlite3DbFree(db, p->u.btree.pIndex->zColAff);
sqlite3DbFreeNN(db, p->u.btree.pIndex);
p->u.btree.pIndex = 0;
}
}
}
/*
** Deallocate internal memory used by a WhereLoop object
*/
static void whereLoopClear(sqlite3 *db, WhereLoop *p){
if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFreeNN(db, p->aLTerm);
whereLoopClearUnion(db, p);
whereLoopInit(p);
}
/*
** Increase the memory allocation for pLoop->aLTerm[] to be at least n.
*/
static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){
WhereTerm **paNew;
if( p->nLSlot>=n ) return SQLITE_OK;
n = (n+7)&~7;
paNew = sqlite3DbMallocRawNN(db, sizeof(p->aLTerm[0])*n);
if( paNew==0 ) return SQLITE_NOMEM_BKPT;
memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);
if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFreeNN(db, p->aLTerm);
p->aLTerm = paNew;
p->nLSlot = n;
return SQLITE_OK;
}
/*
** Transfer content from the second pLoop into the first.
*/
static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){
whereLoopClearUnion(db, pTo);
if( whereLoopResize(db, pTo, pFrom->nLTerm) ){
memset(&pTo->u, 0, sizeof(pTo->u));
return SQLITE_NOMEM_BKPT;
}
memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ);
memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0]));
if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){
pFrom->u.vtab.needFree = 0;
}else if( (pFrom->wsFlags & WHERE_AUTO_INDEX)!=0 ){
pFrom->u.btree.pIndex = 0;
}
return SQLITE_OK;
}
/*
** Delete a WhereLoop object
*/
static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
whereLoopClear(db, p);
sqlite3DbFreeNN(db, p);
}
/*
** Free a WhereInfo structure
*/
static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
int i;
assert( pWInfo!=0 );
for(i=0; i<pWInfo->nLevel; i++){
WhereLevel *pLevel = &pWInfo->a[i];
if( pLevel->pWLoop && (pLevel->pWLoop->wsFlags & WHERE_IN_ABLE) ){
sqlite3DbFree(db, pLevel->u.in.aInLoop);
}
}
sqlite3WhereClauseClear(&pWInfo->sWC);
while( pWInfo->pLoops ){
WhereLoop *p = pWInfo->pLoops;
pWInfo->pLoops = p->pNextLoop;
whereLoopDelete(db, p);
}
assert( pWInfo->pExprMods==0 );
sqlite3DbFreeNN(db, pWInfo);
}
/*
** Return TRUE if all of the following are true:
**
** (1) X has the same or lower cost that Y
** (2) X uses fewer WHERE clause terms than Y
** (3) Every WHERE clause term used by X is also used by Y
** (4) X skips at least as many columns as Y
** (5) If X is a covering index, than Y is too
**
** Conditions (2) and (3) mean that X is a "proper subset" of Y.
** If X is a proper subset of Y then Y is a better choice and ought
** to have a lower cost. This routine returns TRUE when that cost
** relationship is inverted and needs to be adjusted. Constraint (4)
** was added because if X uses skip-scan less than Y it still might
** deserve a lower cost even if it is a proper subset of Y. Constraint (5)
** was added because a covering index probably deserves to have a lower cost
** than a non-covering index even if it is a proper subset.
*/
static int whereLoopCheaperProperSubset(
const WhereLoop *pX, /* First WhereLoop to compare */
const WhereLoop *pY /* Compare against this WhereLoop */
){
int i, j;
if( pX->nLTerm-pX->nSkip >= pY->nLTerm-pY->nSkip ){
return 0; /* X is not a subset of Y */
}
if( pY->nSkip > pX->nSkip ) return 0;
if( pX->rRun >= pY->rRun ){
if( pX->rRun > pY->rRun ) return 0; /* X costs more than Y */
if( pX->nOut > pY->nOut ) return 0; /* X costs more than Y */
}
for(i=pX->nLTerm-1; i>=0; i--){
if( pX->aLTerm[i]==0 ) continue;
for(j=pY->nLTerm-1; j>=0; j--){
if( pY->aLTerm[j]==pX->aLTerm[i] ) break;
}
if( j<0 ) return 0; /* X not a subset of Y since term X[i] not used by Y */
}
if( (pX->wsFlags&WHERE_IDX_ONLY)!=0
&& (pY->wsFlags&WHERE_IDX_ONLY)==0 ){
return 0; /* Constraint (5) */
}
return 1; /* All conditions meet */
}
/*
** Try to adjust the cost of WhereLoop pTemplate upwards or downwards so
** that:
**
** (1) pTemplate costs less than any other WhereLoops that are a proper
** subset of pTemplate
**
** (2) pTemplate costs more than any other WhereLoops for which pTemplate
** is a proper subset.
**
** To say "WhereLoop X is a proper subset of Y" means that X uses fewer
** WHERE clause terms than Y and that every WHERE clause term used by X is
** also used by Y.
*/
static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){
if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return;
for(; p; p=p->pNextLoop){
if( p->iTab!=pTemplate->iTab ) continue;
if( (p->wsFlags & WHERE_INDEXED)==0 ) continue;
if( whereLoopCheaperProperSubset(p, pTemplate) ){
/* Adjust pTemplate cost downward so that it is cheaper than its
** subset p. */
WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut-1));
pTemplate->rRun = p->rRun;
pTemplate->nOut = p->nOut - 1;
}else if( whereLoopCheaperProperSubset(pTemplate, p) ){
/* Adjust pTemplate cost upward so that it is costlier than p since
** pTemplate is a proper subset of p */
WHERETRACE(0x80,("subset cost adjustment %d,%d to %d,%d\n",
pTemplate->rRun, pTemplate->nOut, p->rRun, p->nOut+1));
pTemplate->rRun = p->rRun;
pTemplate->nOut = p->nOut + 1;
}
}
}
/*
** Search the list of WhereLoops in *ppPrev looking for one that can be
** replaced by pTemplate.
**
** Return NULL if pTemplate does not belong on the WhereLoop list.
** In other words if pTemplate ought to be dropped from further consideration.
**
** If pX is a WhereLoop that pTemplate can replace, then return the
** link that points to pX.
**
** If pTemplate cannot replace any existing element of the list but needs
** to be added to the list as a new entry, then return a pointer to the
** tail of the list.
*/
static WhereLoop **whereLoopFindLesser(
WhereLoop **ppPrev,
const WhereLoop *pTemplate
){
WhereLoop *p;
for(p=(*ppPrev); p; ppPrev=&p->pNextLoop, p=*ppPrev){
if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){
/* If either the iTab or iSortIdx values for two WhereLoop are different
** then those WhereLoops need to be considered separately. Neither is
** a candidate to replace the other. */
continue;
}
/* In the current implementation, the rSetup value is either zero
** or the cost of building an automatic index (NlogN) and the NlogN
** is the same for compatible WhereLoops. */
assert( p->rSetup==0 || pTemplate->rSetup==0
|| p->rSetup==pTemplate->rSetup );
/* whereLoopAddBtree() always generates and inserts the automatic index
** case first. Hence compatible candidate WhereLoops never have a larger
** rSetup. Call this SETUP-INVARIANT */
assert( p->rSetup>=pTemplate->rSetup );
/* Any loop using an appliation-defined index (or PRIMARY KEY or
** UNIQUE constraint) with one or more == constraints is better
** than an automatic index. Unless it is a skip-scan. */
if( (p->wsFlags & WHERE_AUTO_INDEX)!=0
&& (pTemplate->nSkip)==0
&& (pTemplate->wsFlags & WHERE_INDEXED)!=0
&& (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0
&& (p->prereq & pTemplate->prereq)==pTemplate->prereq
){
break;
}
/* If existing WhereLoop p is better than pTemplate, pTemplate can be
** discarded. WhereLoop p is better if:
** (1) p has no more dependencies than pTemplate, and
** (2) p has an equal or lower cost than pTemplate
*/
if( (p->prereq & pTemplate->prereq)==p->prereq /* (1) */
&& p->rSetup<=pTemplate->rSetup /* (2a) */
&& p->rRun<=pTemplate->rRun /* (2b) */
&& p->nOut<=pTemplate->nOut /* (2c) */
){
return 0; /* Discard pTemplate */
}
/* If pTemplate is always better than p, then cause p to be overwritten
** with pTemplate. pTemplate is better than p if:
** (1) pTemplate has no more dependences than p, and
** (2) pTemplate has an equal or lower cost than p.
*/
if( (p->prereq & pTemplate->prereq)==pTemplate->prereq /* (1) */
&& p->rRun>=pTemplate->rRun /* (2a) */
&& p->nOut>=pTemplate->nOut /* (2b) */
){
assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */
break; /* Cause p to be overwritten by pTemplate */
}
}
return ppPrev;
}
/*
** Insert or replace a WhereLoop entry using the template supplied.
**
** An existing WhereLoop entry might be overwritten if the new template
** is better and has fewer dependencies. Or the template will be ignored
** and no insert will occur if an existing WhereLoop is faster and has
** fewer dependencies than the template. Otherwise a new WhereLoop is
** added based on the template.
**
** If pBuilder->pOrSet is not NULL then we care about only the
** prerequisites and rRun and nOut costs of the N best loops. That
** information is gathered in the pBuilder->pOrSet object. This special
** processing mode is used only for OR clause processing.
**
** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we
** still might overwrite similar loops with the new template if the
** new template is better. Loops may be overwritten if the following
** conditions are met:
**
** (1) They have the same iTab.
** (2) They have the same iSortIdx.
** (3) The template has same or fewer dependencies than the current loop
** (4) The template has the same or lower cost than the current loop
*/
static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
WhereLoop **ppPrev, *p;
WhereInfo *pWInfo = pBuilder->pWInfo;
sqlite3 *db = pWInfo->pParse->db;
int rc;
/* Stop the search once we hit the query planner search limit */
if( pBuilder->iPlanLimit==0 ){
WHERETRACE(0xffffffff,("=== query planner search limit reached ===\n"));
if( pBuilder->pOrSet ) pBuilder->pOrSet->n = 0;
return SQLITE_DONE;
}
pBuilder->iPlanLimit--;
whereLoopAdjustCost(pWInfo->pLoops, pTemplate);
/* If pBuilder->pOrSet is defined, then only keep track of the costs
** and prereqs.
*/
if( pBuilder->pOrSet!=0 ){
if( pTemplate->nLTerm ){
#if WHERETRACE_ENABLED
u16 n = pBuilder->pOrSet->n;
int x =
#endif
whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
pTemplate->nOut);
#if WHERETRACE_ENABLED /* 0x8 */
if( sqlite3WhereTrace & 0x8 ){
sqlite3DebugPrintf(x?" or-%d: ":" or-X: ", n);
sqlite3WhereLoopPrint(pTemplate, pBuilder->pWC);
}
#endif
}
return SQLITE_OK;
}
/* Look for an existing WhereLoop to replace with pTemplate
*/
ppPrev = whereLoopFindLesser(&pWInfo->pLoops, pTemplate);
if( ppPrev==0 ){
/* There already exists a WhereLoop on the list that is better
** than pTemplate, so just ignore pTemplate */
#if WHERETRACE_ENABLED /* 0x8 */
if( sqlite3WhereTrace & 0x8 ){
sqlite3DebugPrintf(" skip: ");
sqlite3WhereLoopPrint(pTemplate, pBuilder->pWC);
}
#endif
return SQLITE_OK;
}else{
p = *ppPrev;
}
/* If we reach this point it means that either p[] should be overwritten
** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
** WhereLoop and insert it.
*/
#if WHERETRACE_ENABLED /* 0x8 */
if( sqlite3WhereTrace & 0x8 ){
if( p!=0 ){
sqlite3DebugPrintf("replace: ");
sqlite3WhereLoopPrint(p, pBuilder->pWC);
sqlite3DebugPrintf(" with: ");
}else{
sqlite3DebugPrintf(" add: ");
}
sqlite3WhereLoopPrint(pTemplate, pBuilder->pWC);
}
#endif
if( p==0 ){
/* Allocate a new WhereLoop to add to the end of the list */
*ppPrev = p = sqlite3DbMallocRawNN(db, sizeof(WhereLoop));
if( p==0 ) return SQLITE_NOMEM_BKPT;
whereLoopInit(p);
p->pNextLoop = 0;
}else{
/* We will be overwriting WhereLoop p[]. But before we do, first
** go through the rest of the list and delete any other entries besides
** p[] that are also supplated by pTemplate */
WhereLoop **ppTail = &p->pNextLoop;
WhereLoop *pToDel;
while( *ppTail ){
ppTail = whereLoopFindLesser(ppTail, pTemplate);
if( ppTail==0 ) break;
pToDel = *ppTail;
if( pToDel==0 ) break;
*ppTail = pToDel->pNextLoop;
#if WHERETRACE_ENABLED /* 0x8 */
if( sqlite3WhereTrace & 0x8 ){
sqlite3DebugPrintf(" delete: ");
sqlite3WhereLoopPrint(pToDel, pBuilder->pWC);
}
#endif
whereLoopDelete(db, pToDel);
}
}
rc = whereLoopXfer(db, p, pTemplate);
if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
Index *pIndex = p->u.btree.pIndex;
if( pIndex && pIndex->idxType==SQLITE_IDXTYPE_IPK ){
p->u.btree.pIndex = 0;
}
}
return rc;
}
/*
** Adjust the WhereLoop.nOut value downward to account for terms of the
** WHERE clause that reference the loop but which are not used by an
** index.
*
** For every WHERE clause term that is not used by the index
** and which has a truth probability assigned by one of the likelihood(),
** likely(), or unlikely() SQL functions, reduce the estimated number
** of output rows by the probability specified.
**
** TUNING: For every WHERE clause term that is not used by the index
** and which does not have an assigned truth probability, heuristics
** described below are used to try to estimate the truth probability.
** TODO --> Perhaps this is something that could be improved by better
** table statistics.
**
** Heuristic 1: Estimate the truth probability as 93.75%. The 93.75%
** value corresponds to -1 in LogEst notation, so this means decrement
** the WhereLoop.nOut field for every such WHERE clause term.
**
** Heuristic 2: If there exists one or more WHERE clause terms of the
** form "x==EXPR" and EXPR is not a constant 0 or 1, then make sure the
** final output row estimate is no greater than 1/4 of the total number
** of rows in the table. In other words, assume that x==EXPR will filter
** out at least 3 out of 4 rows. If EXPR is -1 or 0 or 1, then maybe the
** "x" column is boolean or else -1 or 0 or 1 is a common default value
** on the "x" column and so in that case only cap the output row estimate
** at 1/2 instead of 1/4.
*/
static void whereLoopOutputAdjust(
WhereClause *pWC, /* The WHERE clause */
WhereLoop *pLoop, /* The loop to adjust downward */
LogEst nRow /* Number of rows in the entire table */
){
WhereTerm *pTerm, *pX;
Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
int i, j;
LogEst iReduce = 0; /* pLoop->nOut should not exceed nRow-iReduce */
assert( (pLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){
assert( pTerm!=0 );
if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break;
if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;
if( (pTerm->prereqAll & notAllowed)!=0 ) continue;
for(j=pLoop->nLTerm-1; j>=0; j--){
pX = pLoop->aLTerm[j];
if( pX==0 ) continue;
if( pX==pTerm ) break;
if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break;
}
if( j<0 ){
if( pTerm->truthProb<=0 ){
/* If a truth probability is specified using the likelihood() hints,
** then use the probability provided by the application. */
pLoop->nOut += pTerm->truthProb;
}else{
/* In the absence of explicit truth probabilities, use heuristics to
** guess a reasonable truth probability. */
pLoop->nOut--;
if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0
&& (pTerm->wtFlags & TERM_HIGHTRUTH)==0 /* tag-20200224-1 */
){
Expr *pRight = pTerm->pExpr->pRight;
int k = 0;
testcase( pTerm->pExpr->op==TK_IS );
if( sqlite3ExprIsInteger(pRight, &k) && k>=(-1) && k<=1 ){
k = 10;
}else{
k = 20;
}
if( iReduce<k ){
pTerm->wtFlags |= TERM_HEURTRUTH;
iReduce = k;
}
}
}
}
}
if( pLoop->nOut > nRow-iReduce ) pLoop->nOut = nRow - iReduce;
}
/*
** Term pTerm is a vector range comparison operation. The first comparison
** in the vector can be optimized using column nEq of the index. This
** function returns the total number of vector elements that can be used
** as part of the range comparison.
**
** For example, if the query is:
**
** WHERE a = ? AND (b, c, d) > (?, ?, ?)
**
** and the index:
**
** CREATE INDEX ... ON (a, b, c, d, e)
**
** then this function would be invoked with nEq=1. The value returned in
** this case is 3.
*/
static int whereRangeVectorLen(
Parse *pParse, /* Parsing context */
int iCur, /* Cursor open on pIdx */
Index *pIdx, /* The index to be used for a inequality constraint */
int nEq, /* Number of prior equality constraints on same index */
WhereTerm *pTerm /* The vector inequality constraint */
){
int nCmp = sqlite3ExprVectorSize(pTerm->pExpr->pLeft);
int i;
nCmp = MIN(nCmp, (pIdx->nColumn - nEq));
for(i=1; i<nCmp; i++){
/* Test if comparison i of pTerm is compatible with column (i+nEq)
** of the index. If not, exit the loop. */
char aff; /* Comparison affinity */
char idxaff = 0; /* Indexed columns affinity */
CollSeq *pColl; /* Comparison collation sequence */
Expr *pLhs = pTerm->pExpr->pLeft->x.pList->a[i].pExpr;
Expr *pRhs = pTerm->pExpr->pRight;
if( pRhs->flags & EP_xIsSelect ){
pRhs = pRhs->x.pSelect->pEList->a[i].pExpr;
}else{
pRhs = pRhs->x.pList->a[i].pExpr;
}
/* Check that the LHS of the comparison is a column reference to
** the right column of the right source table. And that the sort
** order of the index column is the same as the sort order of the
** leftmost index column. */
if( pLhs->op!=TK_COLUMN
|| pLhs->iTable!=iCur
|| pLhs->iColumn!=pIdx->aiColumn[i+nEq]
|| pIdx->aSortOrder[i+nEq]!=pIdx->aSortOrder[nEq]
){
break;
}
testcase( pLhs->iColumn==XN_ROWID );
aff = sqlite3CompareAffinity(pRhs, sqlite3ExprAffinity(pLhs));
idxaff = sqlite3TableColumnAffinity(pIdx->pTable, pLhs->iColumn);
if( aff!=idxaff ) break;
pColl = sqlite3BinaryCompareCollSeq(pParse, pLhs, pRhs);
if( pColl==0 ) break;
if( sqlite3StrICmp(pColl->zName, pIdx->azColl[i+nEq]) ) break;
}
return i;
}
/*
** Adjust the cost C by the costMult facter T. This only occurs if
** compiled with -DSQLITE_ENABLE_COSTMULT
*/
#ifdef SQLITE_ENABLE_COSTMULT
# define ApplyCostMultiplier(C,T) C += T
#else
# define ApplyCostMultiplier(C,T)
#endif
/*
** We have so far matched pBuilder->pNew->u.btree.nEq terms of the
** index pIndex. Try to match one more.
**
** When this function is called, pBuilder->pNew->nOut contains the
** number of rows expected to be visited by filtering using the nEq
** terms only. If it is modified, this value is restored before this
** function returns.
**
** If pProbe->idxType==SQLITE_IDXTYPE_IPK, that means pIndex is
** a fake index used for the INTEGER PRIMARY KEY.
*/
static int whereLoopAddBtreeIndex(
WhereLoopBuilder *pBuilder, /* The WhereLoop factory */
struct SrcList_item *pSrc, /* FROM clause term being analyzed */
Index *pProbe, /* An index on pSrc */
LogEst nInMul /* log(Number of iterations due to IN) */
){
WhereInfo *pWInfo = pBuilder->pWInfo; /* WHERE analyse context */
Parse *pParse = pWInfo->pParse; /* Parsing context */
sqlite3 *db = pParse->db; /* Database connection malloc context */
WhereLoop *pNew; /* Template WhereLoop under construction */
WhereTerm *pTerm; /* A WhereTerm under consideration */
int opMask; /* Valid operators for constraints */
WhereScan scan; /* Iterator for WHERE terms */
Bitmask saved_prereq; /* Original value of pNew->prereq */
u16 saved_nLTerm; /* Original value of pNew->nLTerm */
u16 saved_nEq; /* Original value of pNew->u.btree.nEq */
u16 saved_nBtm; /* Original value of pNew->u.btree.nBtm */
u16 saved_nTop; /* Original value of pNew->u.btree.nTop */
u16 saved_nSkip; /* Original value of pNew->nSkip */
u32 saved_wsFlags; /* Original value of pNew->wsFlags */
LogEst saved_nOut; /* Original value of pNew->nOut */
int rc = SQLITE_OK; /* Return code */
LogEst rSize; /* Number of rows in the table */
LogEst rLogSize; /* Logarithm of table size */
WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
pNew = pBuilder->pNew;
if( db->mallocFailed ) return SQLITE_NOMEM_BKPT;
WHERETRACE(0x800, ("BEGIN %s.addBtreeIdx(%s), nEq=%d, nSkip=%d, rRun=%d\n",
pProbe->pTable->zName,pProbe->zName,
pNew->u.btree.nEq, pNew->nSkip, pNew->rRun));
assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
if( pNew->wsFlags & WHERE_BTM_LIMIT ){
opMask = WO_LT|WO_LE;
}else{
assert( pNew->u.btree.nBtm==0 );
opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE|WO_ISNULL|WO_IS;
}
if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);
assert( pNew->u.btree.nEq<pProbe->nColumn );
saved_nEq = pNew->u.btree.nEq;
saved_nBtm = pNew->u.btree.nBtm;
saved_nTop = pNew->u.btree.nTop;
saved_nSkip = pNew->nSkip;
saved_nLTerm = pNew->nLTerm;
saved_wsFlags = pNew->wsFlags;
saved_prereq = pNew->prereq;
saved_nOut = pNew->nOut;
pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, saved_nEq,
opMask, pProbe);
pNew->rSetup = 0;
rSize = pProbe->aiRowLogEst[0];
rLogSize = estLog(rSize);
for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
u16 eOp = pTerm->eOperator; /* Shorthand for pTerm->eOperator */
LogEst rCostIdx;
LogEst nOutUnadjusted; /* nOut before IN() and WHERE adjustments */
int nIn = 0;
#ifdef SQLITE_ENABLE_STAT4
int nRecValid = pBuilder->nRecValid;
#endif
if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)
&& indexColumnNotNull(pProbe, saved_nEq)
){
continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */
}
if( pTerm->prereqRight & pNew->maskSelf ) continue;
/* Do not allow the upper bound of a LIKE optimization range constraint
** to mix with a lower range bound from some other source */
if( pTerm->wtFlags & TERM_LIKEOPT && pTerm->eOperator==WO_LT ) continue;
/* tag-20191211-001: Do not allow constraints from the WHERE clause to
** be used by the right table of a LEFT JOIN. Only constraints in the
** ON clause are allowed. See tag-20191211-002 for the vtab equivalent. */
if( (pSrc->fg.jointype & JT_LEFT)!=0
&& !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
){
continue;
}
if( IsUniqueIndex(pProbe) && saved_nEq==pProbe->nKeyCol-1 ){
pBuilder->bldFlags1 |= SQLITE_BLDF1_UNIQUE;
}else{
pBuilder->bldFlags1 |= SQLITE_BLDF1_INDEXED;
}
pNew->wsFlags = saved_wsFlags;
pNew->u.btree.nEq = saved_nEq;
pNew->u.btree.nBtm = saved_nBtm;
pNew->u.btree.nTop = saved_nTop;
pNew->nLTerm = saved_nLTerm;
if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
pNew->aLTerm[pNew->nLTerm++] = pTerm;
pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;
assert( nInMul==0
|| (pNew->wsFlags & WHERE_COLUMN_NULL)!=0
|| (pNew->wsFlags & WHERE_COLUMN_IN)!=0
|| (pNew->wsFlags & WHERE_SKIPSCAN)!=0
);
if( eOp & WO_IN ){
Expr *pExpr = pTerm->pExpr;
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
/* "x IN (SELECT ...)": TUNING: the SELECT returns 25 rows */
int i;
nIn = 46; assert( 46==sqlite3LogEst(25) );
/* The expression may actually be of the form (x, y) IN (SELECT...).
** In this case there is a separate term for each of (x) and (y).
** However, the nIn multiplier should only be applied once, not once
** for each such term. The following loop checks that pTerm is the
** first such term in use, and sets nIn back to 0 if it is not. */
for(i=0; i<pNew->nLTerm-1; i++){
if( pNew->aLTerm[i] && pNew->aLTerm[i]->pExpr==pExpr ) nIn = 0;
}
}else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
/* "x IN (value, value, ...)" */
nIn = sqlite3LogEst(pExpr->x.pList->nExpr);
}
if( pProbe->hasStat1 && rLogSize>=10 ){
LogEst M, logK, safetyMargin;
/* Let:
** N = the total number of rows in the table
** K = the number of entries on the RHS of the IN operator
** M = the number of rows in the table that match terms to the
** to the left in the same index. If the IN operator is on
** the left-most index column, M==N.
**
** Given the definitions above, it is better to omit the IN operator
** from the index lookup and instead do a scan of the M elements,
** testing each scanned row against the IN operator separately, if:
**
** M*log(K) < K*log(N)
**
** Our estimates for M, K, and N might be inaccurate, so we build in
** a safety margin of 2 (LogEst: 10) that favors using the IN operator
** with the index, as using an index has better worst-case behavior.
** If we do not have real sqlite_stat1 data, always prefer to use
** the index. Do not bother with this optimization on very small
** tables (less than 2 rows) as it is pointless in that case.
*/
M = pProbe->aiRowLogEst[saved_nEq];
logK = estLog(nIn);
safetyMargin = 10; /* TUNING: extra weight for indexed IN */
if( M + logK + safetyMargin < nIn + rLogSize ){
WHERETRACE(0x40,
("Scan preferred over IN operator on column %d of \"%s\" (%d<%d)\n",
saved_nEq, pProbe->zName, M+logK+10, nIn+rLogSize));
pNew->wsFlags |= WHERE_IN_SEEKSCAN;
}else{
WHERETRACE(0x40,
("IN operator preferred on column %d of \"%s\" (%d>=%d)\n",
saved_nEq, pProbe->zName, M+logK+10, nIn+rLogSize));
}
}
pNew->wsFlags |= WHERE_COLUMN_IN;
}else if( eOp & (WO_EQ|WO_IS) ){
int iCol = pProbe->aiColumn[saved_nEq];
pNew->wsFlags |= WHERE_COLUMN_EQ;
assert( saved_nEq==pNew->u.btree.nEq );
if( iCol==XN_ROWID
|| (iCol>=0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1)
){
if( iCol==XN_ROWID || pProbe->uniqNotNull
|| (pProbe->nKeyCol==1 && pProbe->onError && eOp==WO_EQ)
){
pNew->wsFlags |= WHERE_ONEROW;
}else{
pNew->wsFlags |= WHERE_UNQ_WANTED;
}
}
}else if( eOp & WO_ISNULL ){
pNew->wsFlags |= WHERE_COLUMN_NULL;
}else if( eOp & (WO_GT|WO_GE) ){
testcase( eOp & WO_GT );
testcase( eOp & WO_GE );
pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
pNew->u.btree.nBtm = whereRangeVectorLen(
pParse, pSrc->iCursor, pProbe, saved_nEq, pTerm
);
pBtm = pTerm;
pTop = 0;
if( pTerm->wtFlags & TERM_LIKEOPT ){
/* Range contraints that come from the LIKE optimization are
** always used in pairs. */
pTop = &pTerm[1];
assert( (pTop-(pTerm->pWC->a))<pTerm->pWC->nTerm );
assert( pTop->wtFlags & TERM_LIKEOPT );
assert( pTop->eOperator==WO_LT );
if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
pNew->aLTerm[pNew->nLTerm++] = pTop;
pNew->wsFlags |= WHERE_TOP_LIMIT;
pNew->u.btree.nTop = 1;
}
}else{
assert( eOp & (WO_LT|WO_LE) );
testcase( eOp & WO_LT );
testcase( eOp & WO_LE );
pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
pNew->u.btree.nTop = whereRangeVectorLen(
pParse, pSrc->iCursor, pProbe, saved_nEq, pTerm
);
pTop = pTerm;
pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
pNew->aLTerm[pNew->nLTerm-2] : 0;
}
/* At this point pNew->nOut is set to the number of rows expected to
** be visited by the index scan before considering term pTerm, or the
** values of nIn and nInMul. In other words, assuming that all
** "x IN(...)" terms are replaced with "x = ?". This block updates
** the value of pNew->nOut to account for pTerm (but not nIn/nInMul). */
assert( pNew->nOut==saved_nOut );
if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
/* Adjust nOut using stat4 data. Or, if there is no stat4
** data, using some other estimate. */
whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew);
}else{
int nEq = ++pNew->u.btree.nEq;
assert( eOp & (WO_ISNULL|WO_EQ|WO_IN|WO_IS) );
assert( pNew->nOut==saved_nOut );
if( pTerm->truthProb<=0 && pProbe->aiColumn[saved_nEq]>=0 ){
assert( (eOp & WO_IN) || nIn==0 );
testcase( eOp & WO_IN );
pNew->nOut += pTerm->truthProb;
pNew->nOut -= nIn;
}else{
#ifdef SQLITE_ENABLE_STAT4
tRowcnt nOut = 0;
if( nInMul==0
&& pProbe->nSample
&& pNew->u.btree.nEq<=pProbe->nSampleCol
&& ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
&& OptimizationEnabled(db, SQLITE_Stat4)
){
Expr *pExpr = pTerm->pExpr;
if( (eOp & (WO_EQ|WO_ISNULL|WO_IS))!=0 ){
testcase( eOp & WO_EQ );
testcase( eOp & WO_IS );
testcase( eOp & WO_ISNULL );
rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
}else{
rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut);
}
if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
if( rc!=SQLITE_OK ) break; /* Jump out of the pTerm loop */
if( nOut ){
pNew->nOut = sqlite3LogEst(nOut);
if( nEq==1
/* TUNING: Mark terms as "low selectivity" if they seem likely
** to be true for half or more of the rows in the table.
** See tag-202002240-1 */
&& pNew->nOut+10 > pProbe->aiRowLogEst[0]
){
#if WHERETRACE_ENABLED /* 0x01 */
if( sqlite3WhereTrace & 0x01 ){
sqlite3DebugPrintf(
"STAT4 determines term has low selectivity:\n");
sqlite3WhereTermPrint(pTerm, 999);
}
#endif
pTerm->wtFlags |= TERM_HIGHTRUTH;
if( pTerm->wtFlags & TERM_HEURTRUTH ){
/* If the term has previously been used with an assumption of
** higher selectivity, then set the flag to rerun the
** loop computations. */
pBuilder->bldFlags2 |= SQLITE_BLDF2_2NDPASS;
}
}
if( pNew->nOut>saved_nOut ) pNew->nOut = saved_nOut;
pNew->nOut -= nIn;
}
}
if( nOut==0 )
#endif
{
pNew->nOut += (pProbe->aiRowLogEst[nEq] - pProbe->aiRowLogEst[nEq-1]);
if( eOp & WO_ISNULL ){
/* TUNING: If there is no likelihood() value, assume that a
** "col IS NULL" expression matches twice as many rows
** as (col=?). */
pNew->nOut += 10;
}
}
}
}
/* Set rCostIdx to the cost of visiting selected rows in index. Add
** it to pNew->rRun, which is currently set to the cost of the index
** seek only. Then, if this is a non-covering index, add the cost of
** visiting the rows in the main table. */
assert( pSrc->pTab->szTabRow>0 );
rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pTab->szTabRow;
pNew->rRun = sqlite3LogEstAdd(rLogSize, rCostIdx);
if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16);
}
ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult);
nOutUnadjusted = pNew->nOut;
pNew->rRun += nInMul + nIn;
pNew->nOut += nInMul + nIn;
whereLoopOutputAdjust(pBuilder->pWC, pNew, rSize);
rc = whereLoopInsert(pBuilder, pNew);
if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
pNew->nOut = saved_nOut;
}else{
pNew->nOut = nOutUnadjusted;
}
if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
&& pNew->u.btree.nEq<pProbe->nColumn
){
whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
}
pNew->nOut = saved_nOut;
#ifdef SQLITE_ENABLE_STAT4
pBuilder->nRecValid = nRecValid;
#endif
}
pNew->prereq = saved_prereq;
pNew->u.btree.nEq = saved_nEq;
pNew->u.btree.nBtm = saved_nBtm;
pNew->u.btree.nTop = saved_nTop;
pNew->nSkip = saved_nSkip;
pNew->wsFlags = saved_wsFlags;
pNew->nOut = saved_nOut;
pNew->nLTerm = saved_nLTerm;
/* Consider using a skip-scan if there are no WHERE clause constraints
** available for the left-most terms of the index, and if the average
** number of repeats in the left-most terms is at least 18.
**
** The magic number 18 is selected on the basis that scanning 17 rows
** is almost always quicker than an index seek (even though if the index
** contains fewer than 2^17 rows we assume otherwise in other parts of
** the code). And, even if it is not, it should not be too much slower.
** On the other hand, the extra seeks could end up being significantly
** more expensive. */
assert( 42==sqlite3LogEst(18) );
if( saved_nEq==saved_nSkip
&& saved_nEq+1<pProbe->nKeyCol
&& saved_nEq==pNew->nLTerm
&& pProbe->noSkipScan==0
&& pProbe->hasStat1!=0
&& OptimizationEnabled(db, SQLITE_SkipScan)
&& pProbe->aiRowLogEst[saved_nEq+1]>=42 /* TUNING: Minimum for skip-scan */
&& (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK
){
LogEst nIter;
pNew->u.btree.nEq++;
pNew->nSkip++;
pNew->aLTerm[pNew->nLTerm++] = 0;
pNew->wsFlags |= WHERE_SKIPSCAN;
nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
pNew->nOut -= nIter;
/* TUNING: Because uncertainties in the estimates for skip-scan queries,
** add a 1.375 fudge factor to make skip-scan slightly less likely. */
nIter += 5;
whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);
pNew->nOut = saved_nOut;
pNew->u.btree.nEq = saved_nEq;
pNew->nSkip = saved_nSkip;
pNew->wsFlags = saved_wsFlags;
}
WHERETRACE(0x800, ("END %s.addBtreeIdx(%s), nEq=%d, rc=%d\n",
pProbe->pTable->zName, pProbe->zName, saved_nEq, rc));
return rc;
}
/*
** Return True if it is possible that pIndex might be useful in
** implementing the ORDER BY clause in pBuilder.
**
** Return False if pBuilder does not contain an ORDER BY clause or
** if there is no way for pIndex to be useful in implementing that
** ORDER BY clause.
*/
static int indexMightHelpWithOrderBy(
WhereLoopBuilder *pBuilder,
Index *pIndex,
int iCursor
){
ExprList *pOB;
ExprList *aColExpr;
int ii, jj;
if( pIndex->bUnordered ) return 0;
if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;
for(ii=0; ii<pOB->nExpr; ii++){
Expr *pExpr = sqlite3ExprSkipCollateAndLikely(pOB->a[ii].pExpr);
if( NEVER(pExpr==0) ) continue;
if( pExpr->op==TK_COLUMN && pExpr->iTable==iCursor ){
if( pExpr->iColumn<0 ) return 1;
for(jj=0; jj<pIndex->nKeyCol; jj++){
if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
}
}else if( (aColExpr = pIndex->aColExpr)!=0 ){
for(jj=0; jj<pIndex->nKeyCol; jj++){
if( pIndex->aiColumn[jj]!=XN_EXPR ) continue;
if( sqlite3ExprCompareSkip(pExpr,aColExpr->a[jj].pExpr,iCursor)==0 ){
return 1;
}
}
}
}
return 0;
}
/* Check to see if a partial index with pPartIndexWhere can be used
** in the current query. Return true if it can be and false if not.
*/
static int whereUsablePartialIndex(
int iTab, /* The table for which we want an index */
int isLeft, /* True if iTab is the right table of a LEFT JOIN */
WhereClause *pWC, /* The WHERE clause of the query */
Expr *pWhere /* The WHERE clause from the partial index */
){
int i;
WhereTerm *pTerm;
Parse *pParse = pWC->pWInfo->pParse;
while( pWhere->op==TK_AND ){
if( !whereUsablePartialIndex(iTab,isLeft,pWC,pWhere->pLeft) ) return 0;
pWhere = pWhere->pRight;
}
if( pParse->db->flags & SQLITE_EnableQPSG ) pParse = 0;
for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
Expr *pExpr;
pExpr = pTerm->pExpr;
if( (!ExprHasProperty(pExpr, EP_FromJoin) || pExpr->iRightJoinTable==iTab)
&& (isLeft==0 || ExprHasProperty(pExpr, EP_FromJoin))
&& sqlite3ExprImpliesExpr(pParse, pExpr, pWhere, iTab)
){
return 1;
}
}
return 0;
}
/*
** Add all WhereLoop objects for a single table of the join where the table
** is identified by pBuilder->pNew->iTab. That table is guaranteed to be
** a b-tree table, not a virtual table.
**
** The costs (WhereLoop.rRun) of the b-tree loops added by this function
** are calculated as follows:
**
** For a full scan, assuming the table (or index) contains nRow rows:
**
** cost = nRow * 3.0 // full-table scan
** cost = nRow * K // scan of covering index
** cost = nRow * (K+3.0) // scan of non-covering index
**
** where K is a value between 1.1 and 3.0 set based on the relative
** estimated average size of the index and table records.
**
** For an index scan, where nVisit is the number of index rows visited
** by the scan, and nSeek is the number of seek operations required on
** the index b-tree:
**
** cost = nSeek * (log(nRow) + K * nVisit) // covering index
** cost = nSeek * (log(nRow) + (K+3.0) * nVisit) // non-covering index
**
** Normally, nSeek is 1. nSeek values greater than 1 come about if the
** WHERE clause includes "x IN (....)" terms used in place of "x=?". Or when
** implicit "x IN (SELECT x FROM tbl)" terms are added for skip-scans.
**
** The estimated values (nRow, nVisit, nSeek) often contain a large amount
** of uncertainty. For this reason, scoring is designed to pick plans that
** "do the least harm" if the estimates are inaccurate. For example, a
** log(nRow) factor is omitted from a non-covering index scan in order to
** bias the scoring in favor of using an index, since the worst-case
** performance of using an index is far better than the worst-case performance
** of a full table scan.
*/
static int whereLoopAddBtree(
WhereLoopBuilder *pBuilder, /* WHERE clause information */
Bitmask mPrereq /* Extra prerequesites for using this table */
){
WhereInfo *pWInfo; /* WHERE analysis context */
Index *pProbe; /* An index we are evaluating */
Index sPk; /* A fake index object for the primary key */
LogEst aiRowEstPk[2]; /* The aiRowLogEst[] value for the sPk index */
i16 aiColumnPk = -1; /* The aColumn[] value for the sPk index */
SrcList *pTabList; /* The FROM clause */
struct SrcList_item *pSrc; /* The FROM clause btree term to add */
WhereLoop *pNew; /* Template WhereLoop object */
int rc = SQLITE_OK; /* Return code */
int iSortIdx = 1; /* Index number */
int b; /* A boolean value */
LogEst rSize; /* number of rows in the table */
LogEst rLogSize; /* Logarithm of the number of rows in the table */
WhereClause *pWC; /* The parsed WHERE clause */
Table *pTab; /* Table being queried */
pNew = pBuilder->pNew;
pWInfo = pBuilder->pWInfo;
pTabList = pWInfo->pTabList;
pSrc = pTabList->a + pNew->iTab;
pTab = pSrc->pTab;
pWC = pBuilder->pWC;
assert( !IsVirtual(pSrc->pTab) );
if( pSrc->pIBIndex ){
/* An INDEXED BY clause specifies a particular index to use */
pProbe = pSrc->pIBIndex;
}else if( !HasRowid(pTab) ){
pProbe = pTab->pIndex;
}else{
/* There is no INDEXED BY clause. Create a fake Index object in local
** variable sPk to represent the rowid primary key index. Make this
** fake index the first in a chain of Index objects with all of the real
** indices to follow */
Index *pFirst; /* First of real indices on the table */
memset(&sPk, 0, sizeof(Index));
sPk.nKeyCol = 1;
sPk.nColumn = 1;
sPk.aiColumn = &aiColumnPk;
sPk.aiRowLogEst = aiRowEstPk;
sPk.onError = OE_Replace;
sPk.pTable = pTab;
sPk.szIdxRow = pTab->szTabRow;
sPk.idxType = SQLITE_IDXTYPE_IPK;
aiRowEstPk[0] = pTab->nRowLogEst;
aiRowEstPk[1] = 0;
pFirst = pSrc->pTab->pIndex;
if( pSrc->fg.notIndexed==0 ){
/* The real indices of the table are only considered if the
** NOT INDEXED qualifier is omitted from the FROM clause */
sPk.pNext = pFirst;
}
pProbe = &sPk;
}
rSize = pTab->nRowLogEst;
rLogSize = estLog(rSize);
#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/* Automatic indexes */
if( !pBuilder->pOrSet /* Not part of an OR optimization */
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0
&& (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
&& pSrc->pIBIndex==0 /* Has no INDEXED BY clause */
&& !pSrc->fg.notIndexed /* Has no NOT INDEXED clause */
&& HasRowid(pTab) /* Not WITHOUT ROWID table. (FIXME: Why not?) */
&& !pSrc->fg.isCorrelated /* Not a correlated subquery */
&& !pSrc->fg.isRecursive /* Not a recursive common table expression. */
){
/* Generate auto-index WhereLoops */
WhereTerm *pTerm;
WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
if( pTerm->prereqRight & pNew->maskSelf ) continue;
if( termCanDriveIndex(pTerm, pSrc, 0) ){
pNew->u.btree.nEq = 1;
pNew->nSkip = 0;
pNew->u.btree.pIndex = 0;
pNew->nLTerm = 1;
pNew->aLTerm[0] = pTerm;
/* TUNING: One-time cost for computing the automatic index is
** estimated to be X*N*log2(N) where N is the number of rows in
** the table being indexed and where X is 7 (LogEst=28) for normal
** tables or 0.5 (LogEst=-10) for views and subqueries. The value
** of X is smaller for views and subqueries so that the query planner
** will be more aggressive about generating automatic indexes for
** those objects, since there is no opportunity to add schema
** indexes on subqueries and views. */
pNew->rSetup = rLogSize + rSize;
if( pTab->pSelect==0 && (pTab->tabFlags & TF_Ephemeral)==0 ){
pNew->rSetup += 28;
}else{
pNew->rSetup -= 10;
}
ApplyCostMultiplier(pNew->rSetup, pTab->costMult);
if( pNew->rSetup<0 ) pNew->rSetup = 0;
/* TUNING: Each index lookup yields 20 rows in the table. This
** is more than the usual guess of 10 rows, since we have no way
** of knowing how selective the index will ultimately be. It would
** not be unreasonable to make this value much larger. */
pNew->nOut = 43; assert( 43==sqlite3LogEst(20) );
pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut);
pNew->wsFlags = WHERE_AUTO_INDEX;
pNew->prereq = mPrereq | pTerm->prereqRight;
rc = whereLoopInsert(pBuilder, pNew);
}
}
}
#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
/* Loop over all indices. If there was an INDEXED BY clause, then only
** consider index pProbe. */
for(; rc==SQLITE_OK && pProbe;
pProbe=(pSrc->pIBIndex ? 0 : pProbe->pNext), iSortIdx++
){
int isLeft = (pSrc->fg.jointype & JT_OUTER)!=0;
if( pProbe->pPartIdxWhere!=0
&& !whereUsablePartialIndex(pSrc->iCursor, isLeft, pWC,
pProbe->pPartIdxWhere)
){
testcase( pNew->iTab!=pSrc->iCursor ); /* See ticket [98d973b8f5] */
continue; /* Partial index inappropriate for this query */
}
if( pProbe->bNoQuery ) continue;
rSize = pProbe->aiRowLogEst[0];
pNew->u.btree.nEq = 0;
pNew->u.btree.nBtm = 0;
pNew->u.btree.nTop = 0;
pNew->nSkip = 0;
pNew->nLTerm = 0;
pNew->iSortIdx = 0;
pNew->rSetup = 0;
pNew->prereq = mPrereq;
pNew->nOut = rSize;
pNew->u.btree.pIndex = pProbe;
b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
/* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );
if( pProbe->idxType==SQLITE_IDXTYPE_IPK ){
/* Integer primary key index */
pNew->wsFlags = WHERE_IPK;
/* Full table scan */
pNew->iSortIdx = b ? iSortIdx : 0;
/* TUNING: Cost of full table scan is 3.0*N. The 3.0 factor is an
** extra cost designed to discourage the use of full table scans,
** since index lookups have better worst-case performance if our
** stat guesses are wrong. Reduce the 3.0 penalty slightly
** (to 2.75) if we have valid STAT4 information for the table.
** At 2.75, a full table scan is preferred over using an index on
** a column with just two distinct values where each value has about
** an equal number of appearances. Without STAT4 data, we still want
** to use an index in that case, since the constraint might be for
** the scarcer of the two values, and in that case an index lookup is
** better.
*/
#ifdef SQLITE_ENABLE_STAT4
pNew->rRun = rSize + 16 - 2*((pTab->tabFlags & TF_HasStat4)!=0);
#else
pNew->rRun = rSize + 16;
#endif
ApplyCostMultiplier(pNew->rRun, pTab->costMult);
whereLoopOutputAdjust(pWC, pNew, rSize);
rc = whereLoopInsert(pBuilder, pNew);
pNew->nOut = rSize;
if( rc ) break;
}else{
Bitmask m;
if( pProbe->isCovering ){
pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED;
m = 0;
}else{
m = pSrc->colUsed & pProbe->colNotIdxed;
pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
}
/* Full scan via index */
if( b
|| !HasRowid(pTab)
|| pProbe->pPartIdxWhere!=0
|| pSrc->fg.isIndexedBy
|| ( m==0
&& pProbe->bUnordered==0
&& (pProbe->szIdxRow<pTab->szTabRow)
&& (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
&& sqlite3GlobalConfig.bUseCis
&& OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
)
){
pNew->iSortIdx = b ? iSortIdx : 0;
/* The cost of visiting the index rows is N*K, where K is
** between 1.1 and 3.0, depending on the relative sizes of the
** index and table rows. */
pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow;
if( m!=0 ){
/* If this is a non-covering index scan, add in the cost of
** doing table lookups. The cost will be 3x the number of
** lookups. Take into account WHERE clause terms that can be
** satisfied using just the index, and that do not require a
** table lookup. */
LogEst nLookup = rSize + 16; /* Base cost: N*3 */
int ii;
int iCur = pSrc->iCursor;
WhereClause *pWC2 = &pWInfo->sWC;
for(ii=0; ii<pWC2->nTerm; ii++){
WhereTerm *pTerm = &pWC2->a[ii];
if( !sqlite3ExprCoveredByIndex(pTerm->pExpr, iCur, pProbe) ){
break;
}
/* pTerm can be evaluated using just the index. So reduce
** the expected number of table lookups accordingly */
if( pTerm->truthProb<=0 ){
nLookup += pTerm->truthProb;
}else{
nLookup--;
if( pTerm->eOperator & (WO_EQ|WO_IS) ) nLookup -= 19;
}
}
pNew->rRun = sqlite3LogEstAdd(pNew->rRun, nLookup);
}
ApplyCostMultiplier(pNew->rRun, pTab->costMult);
whereLoopOutputAdjust(pWC, pNew, rSize);
rc = whereLoopInsert(pBuilder, pNew);
pNew->nOut = rSize;
if( rc ) break;
}
}
pBuilder->bldFlags1 = 0;
rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);
if( pBuilder->bldFlags1==SQLITE_BLDF1_INDEXED ){
/* If a non-unique index is used, or if a prefix of the key for
** unique index is used (making the index functionally non-unique)
** then the sqlite_stat1 data becomes important for scoring the
** plan */
pTab->tabFlags |= TF_StatsUsed;
}
#ifdef SQLITE_ENABLE_STAT4
sqlite3Stat4ProbeFree(pBuilder->pRec);
pBuilder->nRecValid = 0;
pBuilder->pRec = 0;
#endif
}
return rc;
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
/*
** Argument pIdxInfo is already populated with all constraints that may
** be used by the virtual table identified by pBuilder->pNew->iTab. This
** function marks a subset of those constraints usable, invokes the
** xBestIndex method and adds the returned plan to pBuilder.
**
** A constraint is marked usable if:
**
** * Argument mUsable indicates that its prerequisites are available, and
**
** * It is not one of the operators specified in the mExclude mask passed
** as the fourth argument (which in practice is either WO_IN or 0).
**
** Argument mPrereq is a mask of tables that must be scanned before the
** virtual table in question. These are added to the plans prerequisites
** before it is added to pBuilder.
**
** Output parameter *pbIn is set to true if the plan added to pBuilder
** uses one or more WO_IN terms, or false otherwise.
*/
static int whereLoopAddVirtualOne(
WhereLoopBuilder *pBuilder,
Bitmask mPrereq, /* Mask of tables that must be used. */
Bitmask mUsable, /* Mask of usable tables */
u16 mExclude, /* Exclude terms using these operators */
sqlite3_index_info *pIdxInfo, /* Populated object for xBestIndex */
u16 mNoOmit, /* Do not omit these constraints */
int *pbIn /* OUT: True if plan uses an IN(...) op */
){
WhereClause *pWC = pBuilder->pWC;
struct sqlite3_index_constraint *pIdxCons;
struct sqlite3_index_constraint_usage *pUsage = pIdxInfo->aConstraintUsage;
int i;
int mxTerm;
int rc = SQLITE_OK;
WhereLoop *pNew = pBuilder->pNew;
Parse *pParse = pBuilder->pWInfo->pParse;
struct SrcList_item *pSrc = &pBuilder->pWInfo->pTabList->a[pNew->iTab];
int nConstraint = pIdxInfo->nConstraint;
assert( (mUsable & mPrereq)==mPrereq );
*pbIn = 0;
pNew->prereq = mPrereq;
/* Set the usable flag on the subset of constraints identified by
** arguments mUsable and mExclude. */
pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
for(i=0; i<nConstraint; i++, pIdxCons++){
WhereTerm *pTerm = &pWC->a[pIdxCons->iTermOffset];
pIdxCons->usable = 0;
if( (pTerm->prereqRight & mUsable)==pTerm->prereqRight
&& (pTerm->eOperator & mExclude)==0
){
pIdxCons->usable = 1;
}
}
/* Initialize the output fields of the sqlite3_index_info structure */
memset(pUsage, 0, sizeof(pUsage[0])*nConstraint);
assert( pIdxInfo->needToFreeIdxStr==0 );
pIdxInfo->idxStr = 0;
pIdxInfo->idxNum = 0;
pIdxInfo->orderByConsumed = 0;
pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
pIdxInfo->estimatedRows = 25;
pIdxInfo->idxFlags = 0;
pIdxInfo->colUsed = (sqlite3_int64)pSrc->colUsed;
/* Invoke the virtual table xBestIndex() method */
rc = vtabBestIndex(pParse, pSrc->pTab, pIdxInfo);
if( rc ){
if( rc==SQLITE_CONSTRAINT ){
/* If the xBestIndex method returns SQLITE_CONSTRAINT, that means
** that the particular combination of parameters provided is unusable.
** Make no entries in the loop table.
*/
WHERETRACE(0xffff, (" ^^^^--- non-viable plan rejected!\n"));
return SQLITE_OK;
}
return rc;
}
mxTerm = -1;
assert( pNew->nLSlot>=nConstraint );
for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
pNew->u.vtab.omitMask = 0;
pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
for(i=0; i<nConstraint; i++, pIdxCons++){
int iTerm;
if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){
WhereTerm *pTerm;
int j = pIdxCons->iTermOffset;
if( iTerm>=nConstraint
|| j<0
|| j>=pWC->nTerm
|| pNew->aLTerm[iTerm]!=0
|| pIdxCons->usable==0
){
sqlite3ErrorMsg(pParse,"%s.xBestIndex malfunction",pSrc->pTab->zName);
testcase( pIdxInfo->needToFreeIdxStr );
return SQLITE_ERROR;
}
testcase( iTerm==nConstraint-1 );
testcase( j==0 );
testcase( j==pWC->nTerm-1 );
pTerm = &pWC->a[j];
pNew->prereq |= pTerm->prereqRight;
assert( iTerm<pNew->nLSlot );
pNew->aLTerm[iTerm] = pTerm;
if( iTerm>mxTerm ) mxTerm = iTerm;
testcase( iTerm==15 );
testcase( iTerm==16 );
if( pUsage[i].omit ){
if( i<16 && ((1<<i)&mNoOmit)==0 ){
testcase( i!=iTerm );
pNew->u.vtab.omitMask |= 1<<iTerm;
}else{
testcase( i!=iTerm );
}
}
if( (pTerm->eOperator & WO_IN)!=0 ){
/* A virtual table that is constrained by an IN clause may not
** consume the ORDER BY clause because (1) the order of IN terms
** is not necessarily related to the order of output terms and
** (2) Multiple outputs from a single IN value will not merge
** together. */
pIdxInfo->orderByConsumed = 0;
pIdxInfo->idxFlags &= ~SQLITE_INDEX_SCAN_UNIQUE;
*pbIn = 1; assert( (mExclude & WO_IN)==0 );
}
}
}
pNew->nLTerm = mxTerm+1;
for(i=0; i<=mxTerm; i++){
if( pNew->aLTerm[i]==0 ){
/* The non-zero argvIdx values must be contiguous. Raise an
** error if they are not */
sqlite3ErrorMsg(pParse,"%s.xBestIndex malfunction",pSrc->pTab->zName);
testcase( pIdxInfo->needToFreeIdxStr );
return SQLITE_ERROR;
}
}
assert( pNew->nLTerm<=pNew->nLSlot );
pNew->u.vtab.idxNum = pIdxInfo->idxNum;
pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
pIdxInfo->needToFreeIdxStr = 0;
pNew->u.vtab.idxStr = pIdxInfo->idxStr;
pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ?
pIdxInfo->nOrderBy : 0);
pNew->rSetup = 0;
pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost);
pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows);
/* Set the WHERE_ONEROW flag if the xBestIndex() method indicated
** that the scan will visit at most one row. Clear it otherwise. */
if( pIdxInfo->idxFlags & SQLITE_INDEX_SCAN_UNIQUE ){
pNew->wsFlags |= WHERE_ONEROW;
}else{
pNew->wsFlags &= ~WHERE_ONEROW;
}
rc = whereLoopInsert(pBuilder, pNew);
if( pNew->u.vtab.needFree ){
sqlite3_free(pNew->u.vtab.idxStr);
pNew->u.vtab.needFree = 0;
}
WHERETRACE(0xffff, (" bIn=%d prereqIn=%04llx prereqOut=%04llx\n",
*pbIn, (sqlite3_uint64)mPrereq,
(sqlite3_uint64)(pNew->prereq & ~mPrereq)));
return rc;
}
/*
** If this function is invoked from within an xBestIndex() callback, it
** returns a pointer to a buffer containing the name of the collation
** sequence associated with element iCons of the sqlite3_index_info.aConstraint
** array. Or, if iCons is out of range or there is no active xBestIndex
** call, return NULL.
*/
SQLITE_API const char *SQLITE_APICALL sqlite3_vtab_collation(sqlite3_index_info *pIdxInfo, int iCons){
HiddenIndexInfo *pHidden = (HiddenIndexInfo*)&pIdxInfo[1];
const char *zRet = 0;
if( iCons>=0 && iCons<pIdxInfo->nConstraint ){
CollSeq *pC = 0;
int iTerm = pIdxInfo->aConstraint[iCons].iTermOffset;
Expr *pX = pHidden->pWC->a[iTerm].pExpr;
if( pX->pLeft ){
pC = sqlite3ExprCompareCollSeq(pHidden->pParse, pX);
}
zRet = (pC ? pC->zName : sqlite3StrBINARY);
}
return zRet;
}
/*
** Add all WhereLoop objects for a table of the join identified by
** pBuilder->pNew->iTab. That table is guaranteed to be a virtual table.
**
** If there are no LEFT or CROSS JOIN joins in the query, both mPrereq and
** mUnusable are set to 0. Otherwise, mPrereq is a mask of all FROM clause
** entries that occur before the virtual table in the FROM clause and are
** separated from it by at least one LEFT or CROSS JOIN. Similarly, the
** mUnusable mask contains all FROM clause entries that occur after the
** virtual table and are separated from it by at least one LEFT or
** CROSS JOIN.
**
** For example, if the query were:
**
** ... FROM t1, t2 LEFT JOIN t3, t4, vt CROSS JOIN t5, t6;
**
** then mPrereq corresponds to (t1, t2) and mUnusable to (t5, t6).
**
** All the tables in mPrereq must be scanned before the current virtual
** table. So any terms for which all prerequisites are satisfied by
** mPrereq may be specified as "usable" in all calls to xBestIndex.
** Conversely, all tables in mUnusable must be scanned after the current
** virtual table, so any terms for which the prerequisites overlap with
** mUnusable should always be configured as "not-usable" for xBestIndex.
*/
static int whereLoopAddVirtual(
WhereLoopBuilder *pBuilder, /* WHERE clause information */
Bitmask mPrereq, /* Tables that must be scanned before this one */
Bitmask mUnusable /* Tables that must be scanned after this one */
){
int rc = SQLITE_OK; /* Return code */
WhereInfo *pWInfo; /* WHERE analysis context */
Parse *pParse; /* The parsing context */
WhereClause *pWC; /* The WHERE clause */
struct SrcList_item *pSrc; /* The FROM clause term to search */
sqlite3_index_info *p; /* Object to pass to xBestIndex() */
int nConstraint; /* Number of constraints in p */
int bIn; /* True if plan uses IN(...) operator */
WhereLoop *pNew;
Bitmask mBest; /* Tables used by best possible plan */
u16 mNoOmit;
assert( (mPrereq & mUnusable)==0 );
pWInfo = pBuilder->pWInfo;
pParse = pWInfo->pParse;
pWC = pBuilder->pWC;
pNew = pBuilder->pNew;
pSrc = &pWInfo->pTabList->a[pNew->iTab];
assert( IsVirtual(pSrc->pTab) );
p = allocateIndexInfo(pParse, pWC, mUnusable, pSrc, pBuilder->pOrderBy,
&mNoOmit);
if( p==0 ) return SQLITE_NOMEM_BKPT;
pNew->rSetup = 0;
pNew->wsFlags = WHERE_VIRTUALTABLE;
pNew->nLTerm = 0;
pNew->u.vtab.needFree = 0;
nConstraint = p->nConstraint;
if( whereLoopResize(pParse->db, pNew, nConstraint) ){
sqlite3DbFree(pParse->db, p);
return SQLITE_NOMEM_BKPT;
}
/* First call xBestIndex() with all constraints usable. */
WHERETRACE(0x800, ("BEGIN %s.addVirtual()\n", pSrc->pTab->zName));
WHERETRACE(0x40, (" VirtualOne: all usable\n"));
rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, 0, p, mNoOmit, &bIn);
/* If the call to xBestIndex() with all terms enabled produced a plan
** that does not require any source tables (IOW: a plan with mBest==0)
** and does not use an IN(...) operator, then there is no point in making
** any further calls to xBestIndex() since they will all return the same
** result (if the xBestIndex() implementation is sane). */
if( rc==SQLITE_OK && ((mBest = (pNew->prereq & ~mPrereq))!=0 || bIn) ){
int seenZero = 0; /* True if a plan with no prereqs seen */
int seenZeroNoIN = 0; /* Plan with no prereqs and no IN(...) seen */
Bitmask mPrev = 0;
Bitmask mBestNoIn = 0;
/* If the plan produced by the earlier call uses an IN(...) term, call
** xBestIndex again, this time with IN(...) terms disabled. */
if( bIn ){
WHERETRACE(0x40, (" VirtualOne: all usable w/o IN\n"));
rc = whereLoopAddVirtualOne(
pBuilder, mPrereq, ALLBITS, WO_IN, p, mNoOmit, &bIn);
assert( bIn==0 );
mBestNoIn = pNew->prereq & ~mPrereq;
if( mBestNoIn==0 ){
seenZero = 1;
seenZeroNoIN = 1;
}
}
/* Call xBestIndex once for each distinct value of (prereqRight & ~mPrereq)
** in the set of terms that apply to the current virtual table. */
while( rc==SQLITE_OK ){
int i;
Bitmask mNext = ALLBITS;
assert( mNext>0 );
for(i=0; i<nConstraint; i++){
Bitmask mThis = (
pWC->a[p->aConstraint[i].iTermOffset].prereqRight & ~mPrereq
);
if( mThis>mPrev && mThis<mNext ) mNext = mThis;
}
mPrev = mNext;
if( mNext==ALLBITS ) break;
if( mNext==mBest || mNext==mBestNoIn ) continue;
WHERETRACE(0x40, (" VirtualOne: mPrev=%04llx mNext=%04llx\n",
(sqlite3_uint64)mPrev, (sqlite3_uint64)mNext));
rc = whereLoopAddVirtualOne(
pBuilder, mPrereq, mNext|mPrereq, 0, p, mNoOmit, &bIn);
if( pNew->prereq==mPrereq ){
seenZero = 1;
if( bIn==0 ) seenZeroNoIN = 1;
}
}
/* If the calls to xBestIndex() in the above loop did not find a plan
** that requires no source tables at all (i.e. one guaranteed to be
** usable), make a call here with all source tables disabled */
if( rc==SQLITE_OK && seenZero==0 ){
WHERETRACE(0x40, (" VirtualOne: all disabled\n"));
rc = whereLoopAddVirtualOne(
pBuilder, mPrereq, mPrereq, 0, p, mNoOmit, &bIn);
if( bIn==0 ) seenZeroNoIN = 1;
}
/* If the calls to xBestIndex() have so far failed to find a plan
** that requires no source tables at all and does not use an IN(...)
** operator, make a final call to obtain one here. */
if( rc==SQLITE_OK && seenZeroNoIN==0 ){
WHERETRACE(0x40, (" VirtualOne: all disabled and w/o IN\n"));
rc = whereLoopAddVirtualOne(
pBuilder, mPrereq, mPrereq, WO_IN, p, mNoOmit, &bIn);
}
}
if( p->needToFreeIdxStr ) sqlite3_free(p->idxStr);
sqlite3DbFreeNN(pParse->db, p);
WHERETRACE(0x800, ("END %s.addVirtual(), rc=%d\n", pSrc->pTab->zName, rc));
return rc;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */
/*
** Add WhereLoop entries to handle OR terms. This works for either
** btrees or virtual tables.
*/
static int whereLoopAddOr(
WhereLoopBuilder *pBuilder,
Bitmask mPrereq,
Bitmask mUnusable
){
WhereInfo *pWInfo = pBuilder->pWInfo;
WhereClause *pWC;
WhereLoop *pNew;
WhereTerm *pTerm, *pWCEnd;
int rc = SQLITE_OK;
int iCur;
WhereClause tempWC;
WhereLoopBuilder sSubBuild;
WhereOrSet sSum, sCur;
struct SrcList_item *pItem;
pWC = pBuilder->pWC;
pWCEnd = pWC->a + pWC->nTerm;
pNew = pBuilder->pNew;
memset(&sSum, 0, sizeof(sSum));
pItem = pWInfo->pTabList->a + pNew->iTab;
iCur = pItem->iCursor;
for(pTerm=pWC->a; pTerm<pWCEnd && rc==SQLITE_OK; pTerm++){
if( (pTerm->eOperator & WO_OR)!=0
&& (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0
){
WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
WhereTerm *pOrTerm;
int once = 1;
int i, j;
sSubBuild = *pBuilder;
sSubBuild.pOrderBy = 0;
sSubBuild.pOrSet = &sCur;
WHERETRACE(0x200, ("Begin processing OR-clause %p\n", pTerm));
for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){
if( (pOrTerm->eOperator & WO_AND)!=0 ){
sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc;
}else if( pOrTerm->leftCursor==iCur ){
tempWC.pWInfo = pWC->pWInfo;
tempWC.pOuter = pWC;
tempWC.op = TK_AND;
tempWC.nTerm = 1;
tempWC.a = pOrTerm;
sSubBuild.pWC = &tempWC;
}else{
continue;
}
sCur.n = 0;
#ifdef WHERETRACE_ENABLED
WHERETRACE(0x200, ("OR-term %d of %p has %d subterms:\n",
(int)(pOrTerm-pOrWC->a), pTerm, sSubBuild.pWC->nTerm));
if( sqlite3WhereTrace & 0x400 ){
sqlite3WhereClausePrint(sSubBuild.pWC);
}
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pItem->pTab) ){
rc = whereLoopAddVirtual(&sSubBuild, mPrereq, mUnusable);
}else
#endif
{
rc = whereLoopAddBtree(&sSubBuild, mPrereq);
}
if( rc==SQLITE_OK ){
rc = whereLoopAddOr(&sSubBuild, mPrereq, mUnusable);
}
assert( rc==SQLITE_OK || rc==SQLITE_DONE || sCur.n==0 );
testcase( rc==SQLITE_DONE );
if( sCur.n==0 ){
sSum.n = 0;
break;
}else if( once ){
whereOrMove(&sSum, &sCur);
once = 0;
}else{
WhereOrSet sPrev;
whereOrMove(&sPrev, &sSum);
sSum.n = 0;
for(i=0; i<sPrev.n; i++){
for(j=0; j<sCur.n; j++){
whereOrInsert(&sSum, sPrev.a[i].prereq | sCur.a[j].prereq,
sqlite3LogEstAdd(sPrev.a[i].rRun, sCur.a[j].rRun),
sqlite3LogEstAdd(sPrev.a[i].nOut, sCur.a[j].nOut));
}
}
}
}
pNew->nLTerm = 1;
pNew->aLTerm[0] = pTerm;
pNew->wsFlags = WHERE_MULTI_OR;
pNew->rSetup = 0;
pNew->iSortIdx = 0;
memset(&pNew->u, 0, sizeof(pNew->u));
for(i=0; rc==SQLITE_OK && i<sSum.n; i++){
/* TUNING: Currently sSum.a[i].rRun is set to the sum of the costs
** of all sub-scans required by the OR-scan. However, due to rounding
** errors, it may be that the cost of the OR-scan is equal to its
** most expensive sub-scan. Add the smallest possible penalty
** (equivalent to multiplying the cost by 1.07) to ensure that
** this does not happen. Otherwise, for WHERE clauses such as the
** following where there is an index on "y":
**
** WHERE likelihood(x=?, 0.99) OR y=?
**
** the planner may elect to "OR" together a full-table scan and an
** index lookup. And other similarly odd results. */
pNew->rRun = sSum.a[i].rRun + 1;
pNew->nOut = sSum.a[i].nOut;
pNew->prereq = sSum.a[i].prereq;
rc = whereLoopInsert(pBuilder, pNew);
}
WHERETRACE(0x200, ("End processing OR-clause %p\n", pTerm));
}
}
return rc;
}
/*
** Add all WhereLoop objects for all tables
*/
static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
WhereInfo *pWInfo = pBuilder->pWInfo;
Bitmask mPrereq = 0;
Bitmask mPrior = 0;
int iTab;
SrcList *pTabList = pWInfo->pTabList;
struct SrcList_item *pItem;
struct SrcList_item *pEnd = &pTabList->a[pWInfo->nLevel];
sqlite3 *db = pWInfo->pParse->db;
int rc = SQLITE_OK;
WhereLoop *pNew;
/* Loop over the tables in the join, from left to right */
pNew = pBuilder->pNew;
whereLoopInit(pNew);
pBuilder->iPlanLimit = SQLITE_QUERY_PLANNER_LIMIT;
for(iTab=0, pItem=pTabList->a; pItem<pEnd; iTab++, pItem++){
Bitmask mUnusable = 0;
pNew->iTab = iTab;
pBuilder->iPlanLimit += SQLITE_QUERY_PLANNER_LIMIT_INCR;
pNew->maskSelf = sqlite3WhereGetMask(&pWInfo->sMaskSet, pItem->iCursor);
if( (pItem->fg.jointype & (JT_LEFT|JT_CROSS))!=0 ){
/* This condition is true when pItem is the FROM clause term on the
** right-hand-side of a LEFT or CROSS JOIN. */
mPrereq = mPrior;
}else{
mPrereq = 0;
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
if( IsVirtual(pItem->pTab) ){
struct SrcList_item *p;
for(p=&pItem[1]; p<pEnd; p++){
if( mUnusable || (p->fg.jointype & (JT_LEFT|JT_CROSS)) ){
mUnusable |= sqlite3WhereGetMask(&pWInfo->sMaskSet, p->iCursor);
}
}
rc = whereLoopAddVirtual(pBuilder, mPrereq, mUnusable);
}else
#endif /* SQLITE_OMIT_VIRTUALTABLE */
{
rc = whereLoopAddBtree(pBuilder, mPrereq);
}
if( rc==SQLITE_OK && pBuilder->pWC->hasOr ){
rc = whereLoopAddOr(pBuilder, mPrereq, mUnusable);
}
mPrior |= pNew->maskSelf;
if( rc || db->mallocFailed ){
if( rc==SQLITE_DONE ){
/* We hit the query planner search limit set by iPlanLimit */
sqlite3_log(SQLITE_WARNING, "abbreviated query algorithm search");
rc = SQLITE_OK;
}else{
break;
}
}
}
whereLoopClear(db, pNew);
return rc;
}
/*
** Examine a WherePath (with the addition of the extra WhereLoop of the 6th
** parameters) to see if it outputs rows in the requested ORDER BY
** (or GROUP BY) without requiring a separate sort operation. Return N:
**
** N>0: N terms of the ORDER BY clause are satisfied
** N==0: No terms of the ORDER BY clause are satisfied
** N<0: Unknown yet how many terms of ORDER BY might be satisfied.
**
** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as
** strict. With GROUP BY and DISTINCT the only requirement is that
** equivalent rows appear immediately adjacent to one another. GROUP BY
** and DISTINCT do not require rows to appear in any particular order as long
** as equivalent rows are grouped together. Thus for GROUP BY and DISTINCT
** the pOrderBy terms can be matched in any order. With ORDER BY, the
** pOrderBy terms must be matched in strict left-to-right order.
*/
static i8 wherePathSatisfiesOrderBy(
WhereInfo *pWInfo, /* The WHERE clause */
ExprList *pOrderBy, /* ORDER BY or GROUP BY or DISTINCT clause to check */
WherePath *pPath, /* The WherePath to check */
u16 wctrlFlags, /* WHERE_GROUPBY or _DISTINCTBY or _ORDERBY_LIMIT */
u16 nLoop, /* Number of entries in pPath->aLoop[] */
WhereLoop *pLast, /* Add this WhereLoop to the end of pPath->aLoop[] */
Bitmask *pRevMask /* OUT: Mask of WhereLoops to run in reverse order */
){
u8 revSet; /* True if rev is known */
u8 rev; /* Composite sort order */
u8 revIdx; /* Index sort order */
u8 isOrderDistinct; /* All prior WhereLoops are order-distinct */
u8 distinctColumns; /* True if the loop has UNIQUE NOT NULL columns */
u8 isMatch; /* iColumn matches a term of the ORDER BY clause */
u16 eqOpMask; /* Allowed equality operators */
u16 nKeyCol; /* Number of key columns in pIndex */
u16 nColumn; /* Total number of ordered columns in the index */
u16 nOrderBy; /* Number terms in the ORDER BY clause */
int iLoop; /* Index of WhereLoop in pPath being processed */
int i, j; /* Loop counters */
int iCur; /* Cursor number for current WhereLoop */
int iColumn; /* A column number within table iCur */
WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
WhereTerm *pTerm; /* A single term of the WHERE clause */
Expr *pOBExpr; /* An expression from the ORDER BY clause */
CollSeq *pColl; /* COLLATE function from an ORDER BY clause term */
Index *pIndex; /* The index associated with pLoop */
sqlite3 *db = pWInfo->pParse->db; /* Database connection */
Bitmask obSat = 0; /* Mask of ORDER BY terms satisfied so far */
Bitmask obDone; /* Mask of all ORDER BY terms */
Bitmask orderDistinctMask; /* Mask of all well-ordered loops */
Bitmask ready; /* Mask of inner loops */
/*
** We say the WhereLoop is "one-row" if it generates no more than one
** row of output. A WhereLoop is one-row if all of the following are true:
** (a) All index columns match with WHERE_COLUMN_EQ.
** (b) The index is unique
** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row.
** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags.
**
** We say the WhereLoop is "order-distinct" if the set of columns from
** that WhereLoop that are in the ORDER BY clause are different for every
** row of the WhereLoop. Every one-row WhereLoop is automatically
** order-distinct. A WhereLoop that has no columns in the ORDER BY clause
** is not order-distinct. To be order-distinct is not quite the same as being
** UNIQUE since a UNIQUE column or index can have multiple rows that
** are NULL and NULL values are equivalent for the purpose of order-distinct.
** To be order-distinct, the columns must be UNIQUE and NOT NULL.
**
** The rowid for a table is always UNIQUE and NOT NULL so whenever the
** rowid appears in the ORDER BY clause, the corresponding WhereLoop is
** automatically order-distinct.
*/
assert( pOrderBy!=0 );
if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;
nOrderBy = pOrderBy->nExpr;
testcase( nOrderBy==BMS-1 );
if( nOrderBy>BMS-1 ) return 0; /* Cannot optimize overly large ORDER BYs */
isOrderDistinct = 1;
obDone = MASKBIT(nOrderBy)-1;
orderDistinctMask = 0;
ready = 0;
eqOpMask = WO_EQ | WO_IS | WO_ISNULL;
if( wctrlFlags & (WHERE_ORDERBY_LIMIT|WHERE_ORDERBY_MAX|WHERE_ORDERBY_MIN) ){
eqOpMask |= WO_IN;
}
for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){
if( iLoop>0 ) ready |= pLoop->maskSelf;
if( iLoop<nLoop ){
pLoop = pPath->aLoop[iLoop];
if( wctrlFlags & WHERE_ORDERBY_LIMIT ) continue;
}else{
pLoop = pLast;
}
if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){
if( pLoop->u.vtab.isOrdered && (wctrlFlags & WHERE_DISTINCTBY)==0 ){
obSat = obDone;
}
break;
}else if( wctrlFlags & WHERE_DISTINCTBY ){
pLoop->u.btree.nDistinctCol = 0;
}
iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;
/* Mark off any ORDER BY term X that is a column in the table of
** the current loop for which there is term in the WHERE
** clause of the form X IS NULL or X=? that reference only outer
** loops.
*/
for(i=0; i<nOrderBy; i++){
if( MASKBIT(i) & obSat ) continue;
pOBExpr = sqlite3ExprSkipCollateAndLikely(pOrderBy->a[i].pExpr);
if( NEVER(pOBExpr==0) ) continue;
if( pOBExpr->op!=TK_COLUMN ) continue;
if( pOBExpr->iTable!=iCur ) continue;
pTerm = sqlite3WhereFindTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
~ready, eqOpMask, 0);
if( pTerm==0 ) continue;
if( pTerm->eOperator==WO_IN ){
/* IN terms are only valid for sorting in the ORDER BY LIMIT
** optimization, and then only if they are actually used
** by the query plan */
assert( wctrlFlags &
(WHERE_ORDERBY_LIMIT|WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX) );
for(j=0; j<pLoop->nLTerm && pTerm!=pLoop->aLTerm[j]; j++){}
if( j>=pLoop->nLTerm ) continue;
}
if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
Parse *pParse = pWInfo->pParse;
CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pOrderBy->a[i].pExpr);
CollSeq *pColl2 = sqlite3ExprCompareCollSeq(pParse, pTerm->pExpr);
assert( pColl1 );
if( pColl2==0 || sqlite3StrICmp(pColl1->zName, pColl2->zName) ){
continue;
}
testcase( pTerm->pExpr->op==TK_IS );
}
obSat |= MASKBIT(i);
}
if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
if( pLoop->wsFlags & WHERE_IPK ){
pIndex = 0;
nKeyCol = 0;
nColumn = 1;
}else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
return 0;
}else{
nKeyCol = pIndex->nKeyCol;
nColumn = pIndex->nColumn;
assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) );
assert( pIndex->aiColumn[nColumn-1]==XN_ROWID
|| !HasRowid(pIndex->pTable));
isOrderDistinct = IsUniqueIndex(pIndex)
&& (pLoop->wsFlags & WHERE_SKIPSCAN)==0;
}
/* Loop through all columns of the index and deal with the ones
** that are not constrained by == or IN.
*/
rev = revSet = 0;
distinctColumns = 0;
for(j=0; j<nColumn; j++){
u8 bOnce = 1; /* True to run the ORDER BY search loop */
assert( j>=pLoop->u.btree.nEq
|| (pLoop->aLTerm[j]==0)==(j<pLoop->nSkip)
);
if( j<pLoop->u.btree.nEq && j>=pLoop->nSkip ){
u16 eOp = pLoop->aLTerm[j]->eOperator;
/* Skip over == and IS and ISNULL terms. (Also skip IN terms when
** doing WHERE_ORDERBY_LIMIT processing). Except, IS and ISNULL
** terms imply that the index is not UNIQUE NOT NULL in which case
** the loop need to be marked as not order-distinct because it can
** have repeated NULL rows.
**
** If the current term is a column of an ((?,?) IN (SELECT...))
** expression for which the SELECT returns more than one column,
** check that it is the only column used by this loop. Otherwise,
** if it is one of two or more, none of the columns can be
** considered to match an ORDER BY term.
*/
if( (eOp & eqOpMask)!=0 ){
if( eOp & (WO_ISNULL|WO_IS) ){
testcase( eOp & WO_ISNULL );
testcase( eOp & WO_IS );
testcase( isOrderDistinct );
isOrderDistinct = 0;
}
continue;
}else if( ALWAYS(eOp & WO_IN) ){
/* ALWAYS() justification: eOp is an equality operator due to the
** j<pLoop->u.btree.nEq constraint above. Any equality other
** than WO_IN is captured by the previous "if". So this one
** always has to be WO_IN. */
Expr *pX = pLoop->aLTerm[j]->pExpr;
for(i=j+1; i<pLoop->u.btree.nEq; i++){
if( pLoop->aLTerm[i]->pExpr==pX ){
assert( (pLoop->aLTerm[i]->eOperator & WO_IN) );
bOnce = 0;
break;
}
}
}
}
/* Get the column number in the table (iColumn) and sort order
** (revIdx) for the j-th column of the index.
*/
if( pIndex ){
iColumn = pIndex->aiColumn[j];
revIdx = pIndex->aSortOrder[j] & KEYINFO_ORDER_DESC;
if( iColumn==pIndex->pTable->iPKey ) iColumn = XN_ROWID;
}else{
iColumn = XN_ROWID;
revIdx = 0;
}
/* An unconstrained column that might be NULL means that this
** WhereLoop is not well-ordered
*/
if( isOrderDistinct
&& iColumn>=0
&& j>=pLoop->u.btree.nEq
&& pIndex->pTable->aCol[iColumn].notNull==0
){
isOrderDistinct = 0;
}
/* Find the ORDER BY term that corresponds to the j-th column
** of the index and mark that ORDER BY term off
*/
isMatch = 0;
for(i=0; bOnce && i<nOrderBy; i++){
if( MASKBIT(i) & obSat ) continue;
pOBExpr = sqlite3ExprSkipCollateAndLikely(pOrderBy->a[i].pExpr);
testcase( wctrlFlags & WHERE_GROUPBY );
testcase( wctrlFlags & WHERE_DISTINCTBY );
if( NEVER(pOBExpr==0) ) continue;
if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
if( iColumn>=XN_ROWID ){
if( pOBExpr->op!=TK_COLUMN ) continue;
if( pOBExpr->iTable!=iCur ) continue;
if( pOBExpr->iColumn!=iColumn ) continue;
}else{
Expr *pIdxExpr = pIndex->aColExpr->a[j].pExpr;
if( sqlite3ExprCompareSkip(pOBExpr, pIdxExpr, iCur) ){
continue;
}
}
if( iColumn!=XN_ROWID ){
pColl = sqlite3ExprNNCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
}
if( wctrlFlags & WHERE_DISTINCTBY ){
pLoop->u.btree.nDistinctCol = j+1;
}
isMatch = 1;
break;
}
if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){
/* Make sure the sort order is compatible in an ORDER BY clause.
** Sort order is irrelevant for a GROUP BY clause. */
if( revSet ){
if( (rev ^ revIdx)!=(pOrderBy->a[i].sortFlags&KEYINFO_ORDER_DESC) ){
isMatch = 0;
}
}else{
rev = revIdx ^ (pOrderBy->a[i].sortFlags & KEYINFO_ORDER_DESC);
if( rev ) *pRevMask |= MASKBIT(iLoop);
revSet = 1;
}
}
if( isMatch && (pOrderBy->a[i].sortFlags & KEYINFO_ORDER_BIGNULL) ){
if( j==pLoop->u.btree.nEq ){
pLoop->wsFlags |= WHERE_BIGNULL_SORT;
}else{
isMatch = 0;
}
}
if( isMatch ){
if( iColumn==XN_ROWID ){
testcase( distinctColumns==0 );
distinctColumns = 1;
}
obSat |= MASKBIT(i);
}else{
/* No match found */
if( j==0 || j<nKeyCol ){
testcase( isOrderDistinct!=0 );
isOrderDistinct = 0;
}
break;
}
} /* end Loop over all index columns */
if( distinctColumns ){
testcase( isOrderDistinct==0 );
isOrderDistinct = 1;
}
} /* end-if not one-row */
/* Mark off any other ORDER BY terms that reference pLoop */
if( isOrderDistinct ){
orderDistinctMask |= pLoop->maskSelf;
for(i=0; i<nOrderBy; i++){
Expr *p;
Bitmask mTerm;
if( MASKBIT(i) & obSat ) continue;
p = pOrderBy->a[i].pExpr;
mTerm = sqlite3WhereExprUsage(&pWInfo->sMaskSet,p);
if( mTerm==0 && !sqlite3ExprIsConstant(p) ) continue;
if( (mTerm&~orderDistinctMask)==0 ){
obSat |= MASKBIT(i);
}
}
}
} /* End the loop over all WhereLoops from outer-most down to inner-most */
if( obSat==obDone ) return (i8)nOrderBy;
if( !isOrderDistinct ){
for(i=nOrderBy-1; i>0; i--){
Bitmask m = MASKBIT(i) - 1;
if( (obSat&m)==m ) return i;
}
return 0;
}
return -1;
}
/*
** If the WHERE_GROUPBY flag is set in the mask passed to sqlite3WhereBegin(),
** the planner assumes that the specified pOrderBy list is actually a GROUP
** BY clause - and so any order that groups rows as required satisfies the
** request.
**
** Normally, in this case it is not possible for the caller to determine
** whether or not the rows are really being delivered in sorted order, or
** just in some other order that provides the required grouping. However,
** if the WHERE_SORTBYGROUP flag is also passed to sqlite3WhereBegin(), then
** this function may be called on the returned WhereInfo object. It returns
** true if the rows really will be sorted in the specified order, or false
** otherwise.
**
** For example, assuming:
**
** CREATE INDEX i1 ON t1(x, Y);
**
** then
**
** SELECT * FROM t1 GROUP BY x,y ORDER BY x,y; -- IsSorted()==1
** SELECT * FROM t1 GROUP BY y,x ORDER BY y,x; -- IsSorted()==0
*/
SQLITE_PRIVATE int sqlite3WhereIsSorted(WhereInfo *pWInfo){
assert( pWInfo->wctrlFlags & WHERE_GROUPBY );
assert( pWInfo->wctrlFlags & WHERE_SORTBYGROUP );
return pWInfo->sorted;
}
#ifdef WHERETRACE_ENABLED
/* For debugging use only: */
static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){
static char zName[65];
int i;
for(i=0; i<nLoop; i++){ zName[i] = pPath->aLoop[i]->cId; }
if( pLast ) zName[i++] = pLast->cId;
zName[i] = 0;
return zName;
}