Data integrity - I want this to be atomic.. I do not want either A or the list of B's saved if the other fails to save.
On Mar 19, 3:16 pm, djidjadji <djidja...@gmail.com> wrote: > Why do you need a transaction for this operation? > To create B objects that are children of some A use > > a=A() > a.put() # create the parent object > bObjs = [B(parent=a, somestring=s) for s in somelist] > db.put(bObjs) > > 2009/3/19 Anonymous Coderrr <greedw...@gmail.com>: > > > > > > > Hi, > > > The documentation for entity-groups and transactions say that entities > > must all be in the same eneity group for transaction operations to > > work. But it does not specifically say how to put entities in the > > same entity group, other than some mention of setting the same parent, > > which it also does not say how to do. > > > Maybe someone could show me specifically how to do this? > > > Let's say I have: > > > class A(db.Model): > > bList = db.ListProperty(db.Key) > > > class B(db.Model): > > someString = db.StringProperty() > > > def tran(self, a, bList): > > bKeys = put_each_list_item_return_keys_as_list(bList) # this > > just calls put() on each item, returns keys > > a.bList = bKeys > > a.put() > > > # the work > > bLIst = createListofBs() > > a = A() > > db.run_in_transaction(tran, a, bList) > > > If I run this, I get this error while the items in the bList are being > > put: > > > BadRequestError: Cannot operate on different entity groups in a > > transaction: (kind=u'B', id=65L) and (kind=u'B', id=None). > > > How do I get everything into one entity group so this transaction will > > commit? > > > Thanks.- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
