org.apache.calcite.sql2rel

Interface SubqueryConverter

public interface SubqueryConverter

SubqueryConverter provides the interface for classes that convert subqueries into equivalent expressions.

Method Summary

Methods

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

Method Detail

canConvertSubquery

boolean canConvertSubquery()

Returns:

true if the subquery can be converted

convertSubquery

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

Converts the subquery to an equivalent expression.

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