/*
* 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 org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
/**
* Distinct the specified path.
*
* @author Marc Prud'hommeaux
*/
class Distinct
extends UnaryOp {
public Distinct(Val val) {
super(val, true);
}
public ExpState initialize(Select sel, ExpContext ctx, int flags) {
// join into related object if present
return initializeValue(sel, ctx, JOIN_REL);
}
protected String getOperator() {
return "DISTINCT";
}
@Override
public void appendTo(Select sel, ExpContext ctx, ExpState state,
SQLBuffer sql, int index) {
Val val = getValue();
if (val instanceof PCPath) {
boolean noParen = getNoParen();
sql.append(getOperator());
sql.append(noParen ? " " : "(");
((PCPath)val).appendTo(sel, ctx, state, sql);
sql.addCastForParam(getOperator(), val);
if (!noParen)
sql.append(")");
} else
super.appendTo(sel, ctx, state, sql, index);
}
}