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/*
* Copyright (c) 2008, 2009, 2011 Oracle, Inc. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution. The Eclipse Public License is available
* at http://www.eclipse.org/legal/epl-v10.html and the Eclipse Distribution License
* is available at http://www.eclipse.org/org/documents/edl-v10.php.
*/
package javax.persistence;
/**
* Defines the values of the javax.persistence.lock.scope property for pessimistic locking. This
* property may be passed as an argument to the methods of the {@link EntityManager}, {@link Query}, and
* {@link TypedQuery} interfaces that allow lock modes to be specified or used with the {@link NamedQuery}
* annotation.
* @since Java Persistence 2.0
*/
public enum PessimisticLockScope
{
/**
* This value defines the default behavior for pessimistic locking.
*
* The persistence provider must lock the database row(s) that correspond to the non-collection-valued
* persistent state of that instance. If a joined inheritance strategy is used, or if the entity is
* otherwise mapped to a secondary table, this entails locking the row(s) for the entity instance in the
* additional table(s). Entity relationships for which the locked entity contains the foreign key will
* also be locked, but not the state of the referenced entities (unless those entities are explicitly
* locked). Element collections and relationships for which the entity does not contain the foreign key
* (such as relationships that are mapped to join tables or unidirectional one-to-many relationships for
* which the target entity contains the foreign key) will not be locked by default.
*/
NORMAL,
/**
* In addition to the behavior for PessimisticLockScope.NORMAL, element collections and
* relationships owned by the entity that are contained in join tables will be locked if the
* javax.persistence.lock.scope property is specified with a value of
* PessimisticLockScope.EXTENDED. The state of entities referenced by such relationships will
* not be locked (unless those entities are explicitly locked). Locking such a relationship or element
* collection generally locks only the rows in the join table or collection table for that relationship or
* collection. This means that phantoms will be possible.
*/
EXTENDED
}