/*
* 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.core;
import com.querydsl.core.types.Expression;
/**
* {@code FetchableQuery} extends {@link Fetchable} and {@link SimpleQuery} with projection changing
* methods and result aggregation functionality using {@link ResultTransformer} instances.
*
* @param <T> element type
* @param <Q> concrete subtype
*/
public interface FetchableQuery<T, Q extends FetchableQuery<T, Q>> extends SimpleQuery<Q>, Fetchable<T> {
/**
* Change the projection of this query
*
* @param <U>
* @param expr new projection
*
* @return the current object
*/
<U> FetchableQuery<U, ?> select(Expression<U> expr);
/**
* Change the projection of this query
*
* @param exprs new projection
* @return the current object
*/
FetchableQuery<Tuple, ?> select(Expression<?>... exprs);
/**
* Apply the given transformer to this {@code FetchableQuery} instance and return the results
*
* @param <S>
* @param transformer result transformer
* @return transformed result
*/
<S> S transform(ResultTransformer<S> transformer);
}