querydsl/querydsl-sql/src/main/java/com/mysema/query/sql/UnionUtils.java
2012-12-17 22:28:22 +02:00

49 lines
1.7 KiB
Java

/*
* Copyright 2012, Mysema Ltd
*
* 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.mysema.query.sql;
import com.mysema.query.types.Expression;
import com.mysema.query.types.ExpressionUtils;
import com.mysema.query.types.OperationImpl;
import com.mysema.query.types.Operator;
import com.mysema.query.types.Path;
import com.mysema.query.types.SubQueryExpression;
/**
* UnionUtils provides static utility methods for Union handling
*
* @author tiwe
*
*/
public final class UnionUtils {
public static Expression<?> union(SubQueryExpression<?>[] union, boolean unionAll) {
final Operator<Object> operator = unionAll ? SQLTemplates.UNION_ALL : SQLTemplates.UNION;
Expression<?> rv = union[0];
for (int i = 1; i < union.length; i++) {
rv = OperationImpl.create(rv.getType(), operator, rv, union[i]);
}
return rv;
}
public static Expression<?> union(SubQueryExpression<?>[] union, Path<?> alias,
boolean unionAll) {
final Expression<?> rv = union(union, unionAll);
return ExpressionUtils.as((Expression)rv, alias);
}
private UnionUtils() {}
}