org.eigenbase.sql2rel
Class SqlToRelConverter.NoOpSubqueryConverter

java.lang.Object
  org.eigenbase.sql2rel.SqlToRelConverter.NoOpSubqueryConverter

All Implemented Interfaces:

SubqueryConverter

Enclosing class:

SqlToRelConverter

private class SqlToRelConverter.NoOpSubqueryConverter
extends Object
implements SubqueryConverter

A default implementation of SubqueryConverter that does no conversion.

Constructor Summary

private

SqlToRelConverter.NoOpSubqueryConverter()

Method Summary

boolean	canConvertSubquery()
RexNode	convertSubquery(SqlCall subquery, SqlToRelConverter parentConverter, boolean isExists, boolean isExplain) Converts the subquery to an equivalent expression.

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlToRelConverter.NoOpSubqueryConverter

private SqlToRelConverter.NoOpSubqueryConverter()

Method Detail

canConvertSubquery

public boolean canConvertSubquery()

Specified by:

canConvertSubquery in interface SubqueryConverter

Returns:

true if the subquery can be converted

convertSubquery

public RexNode convertSubquery(SqlCall subquery,
                               SqlToRelConverter parentConverter,
                               boolean isExists,
                               boolean isExplain)

Description copied from interface: SubqueryConverter

Converts the subquery to an equivalent expression.

Specified by:

convertSubquery in interface SubqueryConverter

Parameters:

subquery - the SqlNode tree corresponding to a subquery

parentConverter - sqlToRelConverter of the parent query

isExists - whether the subquery is part of an EXISTS expression

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

Returns:

the equivalent expression or null if the subquery couldn't be converted