Thanks for the heads up on that interesting method. Just wondering, from your comment in the other thread:
"Or, stick with the lexical path but use the full byte rather than decimal to store the number.. then just 2 bytes give you a max of 64k comments per depth and 200+ deep. " The sort order for StringProperty is in Unicode, so wouldn't you have to use an something like UTF-8? Some pros of this method: - Fast query for children - Possible to reconstruct hierarchy Cons: - Limited depth - Need to do query for siblings before setting the path - Somewhat complex. Need to increment Unicode character On Oct 31, 3:34 am, Anthony <[EMAIL PROTECTED]> wrote: > Store all the parent ids as a hierarchy in a string... > > h="id1/id2/" > h="id1/id2/id3" > h="id1/id2/id3/id4" > h="id5/" > h="id5/id6" > > You can then filter WHERE h > "id1/" and h < "id5/" to get all > children of id1. > > Or you can use entity groups & ancestors. > > More details > here...http://groups.google.com/group/google-appengine/browse_thread/thread/... > > On Oct 31, 8:31 am, Chris Tan <[EMAIL PROTECTED]> wrote: > > > I'm wondering how other people have been modeling hierarchical > > information > > such as nested comments. > > > My first thought was to do something like this: > > > class Comment(db.Model): > > reply_to = db.SelfReferenceProperty(collection_name="replies") > > author = db.UserProperty() > > content = db.TextProperty() > > > However, this isn't scalable, as a query is made for every > > comment in the thread. > > > Any ideas? --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
