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/*
* Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.annotations;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
/**
* A JoinFetch annotation can be used on any relationship mapping,
* (OneToOne, ManyToOne, OneToMany, ManyToMany, BasicCollection, BasicMap).
* It allows the related objects to be joined and read in the same query as the
* source object. Join fetching can also be set at the query level, and it is
* normally recommended to do so as all queries may not require joining.
* Batch reading should be considered as an alternative to join fetching,
* especially for collection relationships as it is typically more efficient.
*
* @author James Sutherland
* @since Oracle TopLink 11.1.1.0.0
*/
@Target({METHOD, FIELD})
@Retention(RUNTIME)
public @interface JoinFetch {
/**
* (Optional) The type of join-fetch to use.
* Either an inner or outer-join,
* an outer-join allows for null/empty values, where as inner does not.
*/
JoinFetchType value() default JoinFetchType.INNER;
}
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