/*
* Copyright 2015, The Querydsl Team (http://www.querydsl.com/team)
*
* Licensed 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 com.querydsl.sql;
import java.util.List;
import com.querydsl.core.types.*;
/**
* UnionUtils provides static utility methods for Union handling
*
* @author tiwe
*
*/
final class UnionUtils {
public static <T> Expression<T> union(List<SubQueryExpression<T>> union, boolean unionAll) {
final Operator operator = unionAll ? SQLOps.UNION_ALL : SQLOps.UNION;
Expression<T> rv = union.get(0);
for (int i = 1; i < union.size(); i++) {
rv = ExpressionUtils.operation(rv.getType(), operator, rv, union.get(i));
}
return rv;
}
public static <T> Expression<T> union(List<SubQueryExpression<T>> union, Path<T> alias,
boolean unionAll) {
final Expression<T> rv = union(union, unionAll);
return ExpressionUtils.as(rv, alias);
}
private UnionUtils() { }
}