org.eigenbase.sql2rel
Class SqlToRelConverter.NoOpSubqueryConverter

java.lang.Object
  extended by 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