Reference properties are a completely separate idea from entity groups (ie ancestor / parent - child relationships).
Reference properties simply store a key; that key can be used to fetch the other entity. They can be changed to point at a different entity as often as you like. An entity's entity group (aka ancestor) is determined by its key -- this can not be changed. One advantage of entity groups is that they allow you to operate on entities within a given group transactionally. Robert On Wed, Aug 3, 2011 at 12:49, Bruno Sandivilli <[email protected]> wrote: > So, if an user X adds and User Y, the user Y will become an ancestor of X ? > And if the user Y adds the user W too, so user X will have two > ancestors(???) ? Any code snippets will be greatful. > Thanks again, for the help guys. > > 2011/8/2 MiuMeet Support <[email protected]> >> >> By the way, have a look >> at: http://devblog.miumeet.com/2011/08/much-more-efficient-implementation-of.html >> It's much more efficient than db.ListProperty(int) >> Cheers, >> -Andrin >> >> On Thu, Jul 28, 2011 at 6:17 PM, Pascal Voitot Dev >> <[email protected]> wrote: >>> >>> good idea also :) >>> >>> On Wed, Jul 27, 2011 at 7:17 PM, Ernesto Oltra <[email protected]> >>> wrote: >>>> >>>> And for followers, you could too shard the lists. You can have several >>>> entities, each with, about 100 results or so (or 1000, or 2000, I prefer >>>> 100 >>>> for easy of serializing/deserializing). All these would have the user as >>>> ancestor. When listing, take only one entity, deserializing its lists (only >>>> 100 results) and show some of them. When listing all, you can use cursors >>>> and some tricks to have the job done (job = paging =) ) >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Google App Engine" group. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msg/google-appengine/-/tRQCOATsWdUJ. >>>> 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. >>> >>> -- >>> 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. >> >> -- >> 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. > > -- > 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. > -- 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.
