Seems I read you can only perform a Save on a particular Entity once during a transaction...the 2nd would fail. In my scenario above, A and B are in different Entity Groups. So, are your designs in agreement with the Max Ross principle as I have described above? Obviously, this A, B, C relation would be common to most any app.
On Sep 19, 12:29 pm, objectuser <kevin.k.le...@gmail.com> wrote: > Interesting. If they're all in the same entity group, how about you > save the group without the keys set, then set the keys and save again, > all in the same transaction? > > On Sep 19, 11:08 am, mlenormand <mickael.lenorm...@gmail.com> wrote: > > > > > All the entities we are talking about are in the SAME entity group in > > order to create/update them in the same transaction. In addition to > > that, we declare an unowned relationship, using "Key" for example. I > > want to save all my entities in the same transaction. > > > On Sep 19, 5:52 pm, objectuser <kevin.k.le...@gmail.com> wrote: > > > > Because your relationships are unowned (so the objects are in > > > different entity groups, right?), you wouldn't be able to save them > > > all in the same transaction anyway. > > > > So you're right: you'll have to save them, which means multiple > > > transactions, and if one of them fails you'll have inconsistent data. > > > > On Sep 19, 8:47 am, mlenormand <mickael.lenorm...@gmail.com> wrote: > > > > > Hi Everybody, > > > > > Here's my problem with JDO and unowned relationships : > > > > > I have several entities of the same kind that are organized in a > > > > hierarchical way, maintained with unowned relationships. > > > > JDO can generate keys for my entities when they are written to the > > > > datastore, but with this option, I can't know my entity's keys until > > > > they are saved to the datastore. If I want to make a reference to an > > > > entity A from an entity B, it seems to be impossible because at this > > > > time I don't know A's key, that will be generated when transaction is > > > > committed. > > > > > One solution would be to use several transactions, each one would > > > > persist an entity, but it's not good because I want to persist all the > > > > entities in the same transaction. > > > > > I know that defining keys myself could solve the problem, but maybe > > > > there is an other solution that would be better ? > > > > > Thank you for your help. And thank you to the GAE team for the > > > > fantastic work you did !- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ 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-java@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 -~----------~----~----~----~------~----~------~--~---
