com.hazelcast.org.apache.calcite.sql2rel.SubQueryConverter Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License, Version 2.0
* (the "License"); you may not use this file except in com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.org.licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.org.apache.calcite.sql2rel;
import com.hazelcast.org.apache.calcite.rex.RexNode;
import com.hazelcast.org.apache.calcite.sql.SqlCall;
/**
* SubQueryConverter provides the interface for classes that convert sub-queries
* into equivalent expressions.
*/
public interface SubQueryConverter {
//~ Methods ----------------------------------------------------------------
/**
* @return Whether the sub-query can be converted
*/
boolean canConvertSubQuery();
/**
* Converts the sub-query to an equivalent expression.
*
* @param subQuery the SqlNode tree corresponding to a sub-query
* @param parentConverter sqlToRelConverter of the parent query
* @param isExists whether the sub-query is part of an EXISTS
* expression
* @param isExplain whether the sub-query is part of an EXPLAIN PLAN
* statement
* @return the equivalent expression or null if the sub-query couldn't be
* converted
*/
RexNode convertSubQuery(
SqlCall subQuery,
SqlToRelConverter parentConverter,
boolean isExists,
boolean isExplain);
}