Package org.apache.drill.exec.planner.sql.parser

Examples of org.apache.drill.exec.planner.sql.parser.SqlShowTables


  public ShowTablesHandler(Planner planner, QueryContext context) { super(planner, context); }

  /** Rewrite the parse tree as SELECT ... FROM INFORMATION_SCHEMA.`TABLES` ... */
  @Override
  public SqlNode rewrite(SqlNode sqlNode) throws RelConversionException{
    SqlShowTables node = unwrap(sqlNode, SqlShowTables.class);
    List<SqlNode> selectList = Lists.newArrayList();
    SqlNode fromClause;
    SqlNode where;

    // create select columns
    selectList.add(new SqlIdentifier("TABLE_SCHEMA", SqlParserPos.ZERO));
    selectList.add(new SqlIdentifier("TABLE_NAME", SqlParserPos.ZERO));

    fromClause = new SqlIdentifier(ImmutableList.of("INFORMATION_SCHEMA", "TABLES"), SqlParserPos.ZERO);

    final SqlIdentifier db = node.getDb();
    String tableSchema;
    if (db != null) {
      tableSchema = db.toString();
    } else {
      // If no schema is given in SHOW TABLES command, list tables from current schema
      SchemaPlus schema = context.getNewDefaultSchema();

      if (isRootSchema(schema)) {
        // If the default schema is a root schema, throw an error to select a default schema
        throw new RelConversionException("No schema selected. Select a schema using 'USE schema' command");
      }

      AbstractSchema drillSchema;

      try {
        drillSchema = getDrillSchema(schema);
      } catch(Exception ex) {
        throw new RelConversionException("Error while rewriting SHOW TABLES query: " + ex.getMessage(), ex);
      }

      tableSchema = drillSchema.getFullSchemaName();
    }

    where = DrillParserUtil.createCondition(
        new SqlIdentifier("TABLE_SCHEMA", SqlParserPos.ZERO),
        SqlStdOperatorTable.EQUALS,
        SqlLiteral.createCharString(tableSchema, CHARSET, SqlParserPos.ZERO));

    SqlNode filter = null;
    final SqlNode likePattern = node.getLikePattern();
    if (likePattern != null) {
      filter = DrillParserUtil.createCondition(
          new SqlIdentifier("TABLE_NAME", SqlParserPos.ZERO),
          SqlStdOperatorTable.LIKE,
          likePattern);
    } else if (node.getWhereClause() != null) {
      filter = node.getWhereClause();
    }

    where = DrillParserUtil.createCondition(where, SqlStdOperatorTable.AND, filter);

    return new SqlSelect(SqlParserPos.ZERO, null, new SqlNodeList(selectList, SqlParserPos.ZERO),
View Full Code Here


  public ShowTablesHandler(SqlHandlerConfig config) { super(config); }

  /** Rewrite the parse tree as SELECT ... FROM INFORMATION_SCHEMA.`TABLES` ... */
  @Override
  public SqlNode rewrite(SqlNode sqlNode) throws RelConversionException{
    SqlShowTables node = unwrap(sqlNode, SqlShowTables.class);
    List<SqlNode> selectList = Lists.newArrayList();
    SqlNode fromClause;
    SqlNode where;

    // create select columns
    selectList.add(new SqlIdentifier("TABLE_SCHEMA", SqlParserPos.ZERO));
    selectList.add(new SqlIdentifier("TABLE_NAME", SqlParserPos.ZERO));

    fromClause = new SqlIdentifier(ImmutableList.of("INFORMATION_SCHEMA", "TABLES"), SqlParserPos.ZERO);

    final SqlIdentifier db = node.getDb();
    String tableSchema;
    if (db != null) {
      tableSchema = db.toString();
    } else {
      // If no schema is given in SHOW TABLES command, list tables from current schema
      SchemaPlus schema = context.getNewDefaultSchema();

      if (isRootSchema(schema)) {
        // If the default schema is a root schema, throw an error to select a default schema
        throw new RelConversionException("No schema selected. Select a schema using 'USE schema' command");
      }

      AbstractSchema drillSchema;

      try {
        drillSchema = getDrillSchema(schema);
      } catch(Exception ex) {
        throw new RelConversionException("Error while rewriting SHOW TABLES query: " + ex.getMessage(), ex);
      }

      tableSchema = drillSchema.getFullSchemaName();
    }

    where = DrillParserUtil.createCondition(
        new SqlIdentifier("TABLE_SCHEMA", SqlParserPos.ZERO),
        SqlStdOperatorTable.EQUALS,
        SqlLiteral.createCharString(tableSchema, CHARSET, SqlParserPos.ZERO));

    SqlNode filter = null;
    final SqlNode likePattern = node.getLikePattern();
    if (likePattern != null) {
      filter = DrillParserUtil.createCondition(
          new SqlIdentifier("TABLE_NAME", SqlParserPos.ZERO),
          SqlStdOperatorTable.LIKE,
          likePattern);
    } else if (node.getWhereClause() != null) {
      filter = node.getWhereClause();
    }

    where = DrillParserUtil.createCondition(where, SqlStdOperatorTable.AND, filter);

    return new SqlSelect(SqlParserPos.ZERO, null, new SqlNodeList(selectList, SqlParserPos.ZERO),
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