You can add a property like "isEmpty". If "None" is not a valid value in your list, you can store it as [None], and after get it from db, you can check and delete this value.
2009/5/21 Nick Johnson (Google) <[email protected]> > > Hi mind4u, > > It's not possible to filter for entities that don't have values for a > particular property. If you need to retrieve this entity, you will > need to find some other criteria, or iterate through all candidate > entities looking for it. > > -Nick Johnson > > On Wed, May 20, 2009 at 9:40 AM, mind4u <[email protected]> wrote: > > > > Static listproperty is not stored in datastore if it does'nt have any > > value. > > So, I don't know how to get entities which have empty listproperty . > > > > How can I get t1 by gql from follow example? > > > --------------------------------------------------------------------------------------- > > > > class TestList(db.Model): > > acl = db.ListProperty(int) > > > > t = TestList(acl=[1,2,3]) > > t.put() > > > > t1 = TestList(acl=[]) > > t1.put() > > > > t2 = TestList(acl=[4,5]) > > t2.put() > > > > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
