"Sammy8306" wrote : As far as I know, SMPC is scoped over the conversation. That would be the implicit temporary conversation if no conversation is started manually. | You have two options: either make sure the edits happen in the same conversation (and therefore the same EM) or merge the offending object into the second EM instance (using em.merge()). Hmm. I thought to have done that. The selectBenutzer() method which is called on selection of a Benutzer in the list calls beginConversation(), which is marked with @Begin(flushMode = FlushModeType.MANUAL) then when the save butten is pressed commit() is called which is marked with @End(beforeRedirect=true) and calls em.flush(). Would'nt that mean i span a conversation around the whole edit process ? "petemuir" wrote : Yes, use a SMPC, not an extended PC. You don't want the @Transactional on those methods (it's an entity bean) Can you please explain why thats not needed? Do Entity beans always have an implicit transactional behavior?? "petemuir" wrote : and you probably want to let hibernate take care up updating the relationship for you - call entityManager.refresh(foo) to get hibernate to do this. cool. So i dont need the add/remove on the list? But where should i do that call? I suppose i cant do it in the entity itself, because that would be ugly despite the fact that the entity doesnt know the PC. So i tried to do it in BenutzerManager.save() with no luck like that: | @DataModelSelection | @Out(required = false) | private BenutzerImpl selectedBenutzer; | | private GruppeImpl selectedGruppe; | | public void selectBenutzer() | { | selectedGruppe = mowitaEntityManager.merge(selectedBenutzer.getGruppe()); | beginConversation(); | // log.info("BenutzerManager selectBenutzer(#0)\n", selectedBenutzer); | // log.info("BenutzerManager editedBenutzer(#0)\n", editedBenutzer); | | // benutzer= selectedBenutzer; | } | | @End(beforeRedirect=true) | public void commit() | { | log.info("Merging selectedBenutzer: #0", selectedBenutzer); | mowitaEntityManager.merge(selectedBenutzer); | | log.info("refreshing selectedGruppe: #0", selectedGruppe); | mowitaEntityManager.refresh(selectedGruppe); | | log.info("flushing..."); | mowitaEntityManager.flush(); | | mowitaEntityManager.refresh(selectedBenutzer.getGruppe()); | mowitaEntityManager.flush(); | | } | I get an java.lang.IllegalArgumentException: Entity not managed by the call to mowitaEntityManager.refresh(selectedGruppe); The question is, how to get the gruppe that was selected before the user choose a new one, because if i call selectedBenutzer.getGruppe() in the save() method i already get the new Gruppe. Refreshing that newly selected Gruppe seems to work although i gat a lazy initialisation exception afterwards, when trying ot show the list of Gruppen. Thanks for your help, Tobias View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4040889#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...