private void processAlterTable()

in HSQL/src/org/hsqldb1/DatabaseCommandInterpreter.java [1618:1771]
114 lines of code
25 McCabe index (conditional complexity)

    private void processAlterTable() throws HsqlException {

        String tableName = tokenizer.getName();
        String schema =
            session.getSchemaNameForWrite(tokenizer.getLongNameFirst());
        Table t = database.schemaManager.getUserTable(session, tableName,
            schema);
        String token;

        if (t.isView()) {
            throw Trace.error(Trace.NOT_A_TABLE);
        }

        session.setScripting(true);

        token = tokenizer.getSimpleToken();

        switch (Token.get(token)) {

            case Token.RENAME : {
                processAlterTableRename(t);

                return;
            }
            case Token.ADD : {
                HsqlName cname = null;

                if (tokenizer.isGetThis(Token.T_CONSTRAINT)) {
                    token = tokenizer.getName();

                    String constraintSchema = tokenizer.getLongNameFirst();

                    if (constraintSchema != null) {
                        constraintSchema = session.getSchemaNameForWrite(
                            tokenizer.getLongNameFirst());

                        if (!t.getSchemaName().equals(constraintSchema)) {
                            throw Trace.error(
                                Trace.INVALID_SCHEMA_NAME_NO_SUBCLASS,
                                constraintSchema);
                        }
                    }

                    cname = database.nameManager.newHsqlName(token,
                            tokenizer.wasQuotedIdentifier());
                }

                token = tokenizer.getString();

                if (tokenizer.wasQuotedIdentifier()
                        && tokenizer.wasSimpleName()) {
                    tokenizer.back();
                    processAlterTableAddColumn(t);

                    return;
                }

                if (!tokenizer.wasSimpleToken()) {
                    throw Trace.error(Trace.UNEXPECTED_TOKEN, token);
                }

                switch (Token.get(token)) {

                    case Token.FOREIGN :
                        tokenizer.getThis(Token.T_KEY);
                        processAlterTableAddForeignKeyConstraint(t, cname);

                        return;

                    case Token.UNIQUE :
                        processAlterTableAddUniqueConstraint(t, cname);

                        return;

                    case Token.CHECK :
                        processAlterTableAddCheckConstraint(t, cname);

                        return;

                    case Token.PRIMARY :
                        tokenizer.getThis(Token.T_KEY);
                        processAlterTableAddPrimaryKey(t, cname);

                        return;

                    default :
                        if (cname != null) {
                            throw Trace.error(Trace.UNEXPECTED_TOKEN, token);
                        }

                        tokenizer.back();
                    case Token.COLUMN :
                        processAlterTableAddColumn(t);

                        return;
                }
            }
            case Token.DROP : {
                token = tokenizer.getString();

                if (tokenizer.wasQuotedIdentifier()
                        && tokenizer.wasSimpleName()) {
                    tokenizer.back();
                    processAlterTableDropColumn(t);

                    return;
                }

                if (!tokenizer.wasSimpleToken()) {
                    throw Trace.error(Trace.UNEXPECTED_TOKEN, token);
                }

                switch (Token.get(token)) {

                    case Token.PRIMARY :
                        tokenizer.getThis(Token.T_KEY);

                        if (t.hasPrimaryKey()) {
                            processAlterTableDropConstraint(
                                t, t.getPrimaryConstraint().getName().name);
                        } else {
                            throw Trace.error(Trace.CONSTRAINT_NOT_FOUND,
                                              Trace.TABLE_HAS_NO_PRIMARY_KEY,
                                              new Object[] {
                                "PRIMARY KEY", t.getName().name
                            });
                        }

                        return;

                    case Token.CONSTRAINT :
                        processAlterTableDropConstraint(t);

                        return;

                    default :
                        tokenizer.back();
                    case Token.COLUMN :
                        processAlterTableDropColumn(t);

                        return;
                }
            }
            case Token.ALTER : {
                tokenizer.isGetThis(Token.T_COLUMN);
                processAlterColumn(t);

                return;
            }
            default : {
                throw Trace.error(Trace.UNEXPECTED_TOKEN, token);
            }
        }
    }