Alex, You can only order by properties on the model itself. If you want to order by a property on a referenced model, you need to include it. So in your case you might want to add a "reelName" property to Frame, then just be sure you handle updating that property when you change the name on Reel.
Robert On Wed, Feb 24, 2010 at 9:09 AM, Alex <alexle...@googlemail.com> wrote: > Hi, > Is it possible to do anything with a reference property other than > cycle through the referenced objects in whatever order they are > returned? For example I have a number of reference properties to > instances where the creation date is crucial to how they are > subsequently managed. Is there a way to order the result? > > class Reel(db.Model): > name = db.StringProperty() > > class Frame(db.Model): > # datetime.datetime.now() when the object is first created. > auto_now_add_prop = db.DateTimeProperty(auto_now_add=True) > # reference to the one and only reel this frame belong to > reel = db.ReferenceProperty(Reel, collection_name='frames') > > I would like to order 'reel.frames' depending on the > 'auto_now_add_prop' date. Is this the right way to access these > instances if date order access is frequent and crucial? > The Frame model will have millions of instances so a query there > matching for a given Reel instance would be expensive. Ideas/advice/a > thread I haven't seen? > > Alex > > -- > 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-appeng...@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. > > -- 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-appeng...@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.
