It's the kind-hearted man Ian Marshall again. :) I have solved the problem mentioned above by setting the key of a class to be stored a key with common ancestor like u said. But there's one thing i think we should noticed that if we retrieve a entity by a key with no parents ,say we create it by KeyFactory using the key's name like:
KeyFactory.createKey(a.class.getSimpleName(),"name"); it can still be retrieve but it seems that the app engine don't recognize it a entity in same entity group with others.That is to say, we can't manipulate it with other entites that is in the same entity group in the same transaction. but if we create a key like this: KeyFactory.createKey(parents.class.getSimpleName,a.class.getSimpleName(),"name"); Everything's alright. -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
