/*
* 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 compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.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 org.apache.openjpa.jdbc.kernel.exps;
import java.util.Map;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
import org.apache.openjpa.kernel.exps.Expression;
/**
* An Expression represents a query ready for execution. Generally, it is
* a set of conditions that must be met for the query to be true.
*
* @author Abe White
*/
interface Exp
extends Expression {
/**
* Initialize the expression. This method should recursively
* initialize any sub-expressions or values.
*
* @param contains map of relation paths to the number of times
* the paths appear in a contains() expression;
* used to ensure paths used for contains() within
* the same AND expression used different aliases
*/
public ExpState initialize(Select sel, ExpContext ctx, Map contains);
/**
* Append the SQL for this expression to the given buffer. The SQL
* should optionally include any joins this expression needs.
*/
public void appendTo(Select sel, ExpContext ctx, ExpState state,
SQLBuffer buf);
/**
* Select just the columns for this expression.
*/
public void selectColumns(Select sel, ExpContext ctx, ExpState state,
boolean pks);
}