A call to EntityManager.flush();
will force the data to be persist in the database immediately as EntityManager.persist()
will not (depending on how the EntityManager is configured : FlushModeType (AUTO or COMMIT) by default it's set to AUTO and a flush will be done automatically by if it's set to COMMIT the persitence of the data to the underlying database will be delayed when the transaction is commited).
~ Answered on 2013-07-17 15:21:35