protected String generateAlterTableSql()

in catalogs/catalog-jdbc-mysql/src/main/java/org/apache/gravitino/catalog/mysql/operation/MysqlTableOperations.java [215:316]
93 lines of code
23 McCabe index (conditional complexity)

  protected String generateAlterTableSql(
      String databaseName, String tableName, TableChange... changes) {
    // Not all operations require the original table information, so lazy loading is used here
    JdbcTable lazyLoadTable = null;
    TableChange.UpdateComment updateComment = null;
    List<TableChange.SetProperty> setProperties = new ArrayList<>();
    List<String> alterSql = new ArrayList<>();
    for (int i = 0; i < changes.length; i++) {
      TableChange change = changes[i];
      if (change instanceof TableChange.UpdateComment) {
        updateComment = (TableChange.UpdateComment) change;
      } else if (change instanceof TableChange.SetProperty) {
        // The set attribute needs to be added at the end.
        setProperties.add(((TableChange.SetProperty) change));
      } else if (change instanceof TableChange.RemoveProperty) {
        // mysql does not support deleting table attributes, it can be replaced by Set Property
        throw new IllegalArgumentException("Remove property is not supported yet");
      } else if (change instanceof TableChange.AddColumn) {
        TableChange.AddColumn addColumn = (TableChange.AddColumn) change;
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        alterSql.add(addColumnFieldDefinition(addColumn));
      } else if (change instanceof TableChange.RenameColumn) {
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        TableChange.RenameColumn renameColumn = (TableChange.RenameColumn) change;
        alterSql.add(renameColumnFieldDefinition(renameColumn, lazyLoadTable));
      } else if (change instanceof TableChange.UpdateColumnDefaultValue) {
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        TableChange.UpdateColumnDefaultValue updateColumnDefaultValue =
            (TableChange.UpdateColumnDefaultValue) change;
        alterSql.add(
            updateColumnDefaultValueFieldDefinition(updateColumnDefaultValue, lazyLoadTable));
      } else if (change instanceof TableChange.UpdateColumnType) {
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        TableChange.UpdateColumnType updateColumnType = (TableChange.UpdateColumnType) change;
        alterSql.add(updateColumnTypeFieldDefinition(updateColumnType, lazyLoadTable));
      } else if (change instanceof TableChange.UpdateColumnComment) {
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        TableChange.UpdateColumnComment updateColumnComment =
            (TableChange.UpdateColumnComment) change;
        alterSql.add(updateColumnCommentFieldDefinition(updateColumnComment, lazyLoadTable));
      } else if (change instanceof TableChange.UpdateColumnPosition) {
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        TableChange.UpdateColumnPosition updateColumnPosition =
            (TableChange.UpdateColumnPosition) change;
        alterSql.add(updateColumnPositionFieldDefinition(updateColumnPosition, lazyLoadTable));
      } else if (change instanceof TableChange.DeleteColumn) {
        TableChange.DeleteColumn deleteColumn = (TableChange.DeleteColumn) change;
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        String deleteColSql = deleteColumnFieldDefinition(deleteColumn, lazyLoadTable);
        if (StringUtils.isNotEmpty(deleteColSql)) {
          alterSql.add(deleteColSql);
        }
      } else if (change instanceof TableChange.UpdateColumnNullability) {
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        alterSql.add(
            updateColumnNullabilityDefinition(
                (TableChange.UpdateColumnNullability) change, lazyLoadTable));
      } else if (change instanceof TableChange.AddIndex) {
        alterSql.add(addIndexDefinition((TableChange.AddIndex) change));
      } else if (change instanceof TableChange.DeleteIndex) {
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        alterSql.add(deleteIndexDefinition(lazyLoadTable, (TableChange.DeleteIndex) change));
      } else if (change instanceof TableChange.UpdateColumnAutoIncrement) {
        lazyLoadTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        alterSql.add(
            updateColumnAutoIncrementDefinition(
                lazyLoadTable, (TableChange.UpdateColumnAutoIncrement) change));
      } else {
        throw new IllegalArgumentException(
            "Unsupported table change type: " + change.getClass().getName());
      }
    }
    if (!setProperties.isEmpty()) {
      alterSql.add(generateTableProperties(setProperties));
    }

    // Last modified comment
    if (null != updateComment) {
      String newComment = updateComment.getNewComment();
      if (null == StringIdentifier.fromComment(newComment)) {
        // Detect and add Gravitino id.
        JdbcTable jdbcTable = getOrCreateTable(databaseName, tableName, lazyLoadTable);
        StringIdentifier identifier = StringIdentifier.fromComment(jdbcTable.comment());
        if (null != identifier) {
          newComment = StringIdentifier.addToComment(identifier, newComment);
        }
      }
      alterSql.add("COMMENT '" + newComment + "'");
    }

    if (!setProperties.isEmpty()) {
      alterSql.add(generateTableProperties(setProperties));
    }

    if (CollectionUtils.isEmpty(alterSql)) {
      return "";
    }
    // Return the generated SQL statement
    String result = "ALTER TABLE `" + tableName + "`\n" + String.join(",\n", alterSql) + ";";
    LOG.info("Generated alter table:{} sql: {}", databaseName + "." + tableName, result);
    return result;
  }