net.sf.farrago.query
Class FarragoReentrantSubquery

java.lang.Object
  net.sf.farrago.query.FarragoReentrantStmt
      net.sf.farrago.query.FarragoReentrantStmtExecutor
          net.sf.farrago.query.FarragoReentrantSubquery

public class FarragoReentrantSubquery
extends FarragoReentrantStmtExecutor

Extends FarragoReentrantStmtExecutor to handle subqueries. The subquery will be evaluated to a constant.

If the subquery is part of an EXISTS expression, the constant returned is either TRUE or FALSE depending on whether the subquery returned zero or at least one row.

Otherwise, the subquery must be a scalar subquery.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/query/FarragoReentrantSubquery.java#6 $

Author:

Zelaine Fong

Field Summary

private boolean	isExists
private boolean	isExplain
private SqlToRelConverter	parentConverter
private SqlCall	subq

Fields inherited from class net.sf.farrago.query.FarragoReentrantStmtExecutor

failed, results, rexBuilder

Constructor Summary

FarragoReentrantSubquery(SqlCall subq, SqlToRelConverter parentConverter, boolean isExists, boolean isExplain, List<RexNode> results)
Constructs a FarragoReentrantSubquery.

Method Summary

protected void

executeImpl() Supplies subclass-specific behavior.

Methods inherited from class net.sf.farrago.query.FarragoReentrantStmtExecutor

executePlan

Methods inherited from class net.sf.farrago.query.FarragoReentrantStmt

execute, getPreparingStmt, getRootStmtContext, getStmtContext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

subq

private final SqlCall subq

parentConverter

private final SqlToRelConverter parentConverter

isExists

private final boolean isExists

isExplain

private final boolean isExplain

Constructor Detail

FarragoReentrantSubquery

FarragoReentrantSubquery(SqlCall subq,
                         SqlToRelConverter parentConverter,
                         boolean isExists,
                         boolean isExplain,
                         List<RexNode> results)

Constructs a FarragoReentrantSubquery.

Parameters:

subq - the subquery to evaluate

parentConverter - sqlToRelConverter associated with the parent query

isExists - whether the subquery is part of an EXISTS expression

isExplain - whether the subquery is part of an EXPLAIN PLAN statement

results - the resulting evaluated expressions

Method Detail

executeImpl

protected void executeImpl()
                    throws Exception

Description copied from class: FarragoReentrantStmt

Supplies subclass-specific behavior.

Specified by:

executeImpl in class FarragoReentrantStmt

Throws:

Exception