org.apache.calcite.sql2rel

Interface SubQueryConverter

All Known Implementing Classes:

SqlToRelConverter.NoOpSubQueryConverter

public interface SubQueryConverter

SubQueryConverter provides the interface for classes that convert sub-queries into equivalent expressions.

Method Summary

Modifier and Type	Method and Description
boolean	canConvertSubQuery()
RexNode	convertSubQuery(SqlCall subQuery, SqlToRelConverter parentConverter, boolean isExists, boolean isExplain) Converts the sub-query to an equivalent expression.

Method Detail

canConvertSubQuery

boolean canConvertSubQuery()

Returns:

Whether the sub-query can be converted

convertSubQuery

RexNode convertSubQuery(SqlCall subQuery,
                        SqlToRelConverter parentConverter,
                        boolean isExists,
                        boolean isExplain)

Converts the sub-query to an equivalent expression.

Parameters:

subQuery - the SqlNode tree corresponding to a sub-query

parentConverter - sqlToRelConverter of the parent query

isExists - whether the sub-query is part of an EXISTS expression

isExplain - whether the sub-query is part of an EXPLAIN PLAN statement

Returns:

the equivalent expression or null if the sub-query couldn't be converted