PersistenceException is thrown or not depending on wheter there is @Version annotation -------------------------------------------------------------------------------------- Key: EJB-422 URL: http://opensource.atlassian.com/projects/hibernate/browse/EJB-422 Project: Hibernate Entity Manager Issue Type: Bug Components: EntityManager Environment: discovered on Windowx XP, using JPA with Hibernate implementation Reporter: Paweł Szulc Example: PriorityProjectRef is normal entity class. If we dont use OptimisticLocking for it (there is no @Version) then test that u can see below will pass. Persisting entity with id set to value of existing entitty will throw an exception - PersistenceException. @Test(expected = PersistenceException.class) public void testUniqueKey() { PriorityProjectRef entity = new PriorityProjectRef(); dao.persist(entity); PriorityProjectRef entity2 = new PriorityProjectRef(); entity2.setId(entity.getId()); dao.persist(entity2); } However if we add to our PriorityProjectRef entity class new field annotated with @Version (to use optimistic locking), the test will fail. There will be no PersistenceException thrown. Second entity will be saved, with new id set from the sequence. In other words: without @Version - only one entity persisted, PersistenceException thrown with @Version - two enites persisted (with different IDs), PersistenceException not thrown -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira