Not to be annoying, but can you post an example?
Just to organize the things in my head...
Thanks again.
On Fri, Jun 25, 2010 at 2:41 AM, Carles Gonzalez <carle...@gmail.com> wrote:
> Very interesting!
>
> I'll try tomorrow.
>
> Thanks a lot, Dave.
>
> On Fri, Jun 25, 2010 at 1:21 AM, dlypka <dly...@gmail.com> wrote:
>> I've done a parent - to - many child GAE / web2py implementation using
>> SelfReference fields (or you can use Reference as well) using the
>> technique for adding native GAE fields into a web2py table definition.
>>
>> It gives fantastic retrieval performance because GAE automatically
>> adds the link from the child back into the parent's reference list
>> at the time you create each child. When you later query for the
>> parent, voila GAE retrieves all the child entities along with it in
>> one backend call!
>>
>> Hopefully this technique is relevant to your application.
>>
>> I also develop some other tricks for inheriting native GAE classes
>> into your web2py model, though
>> this is less attractive perhaps now that GAE native properties can be
>> directly declared in web2py tables.
>>
>> - Dave Lypka.
>>
>> On Jun 21, 10:25 am, Carles Gonzalez <carle...@gmail.com> wrote:
>>> Hi,
>>>
>>> I have developed some applications in web2py, and 2 are running
>>> currently in gae, but now i have serious problem.
>>>
>>> My current project is a social application, and when i design
>>> (example) the tables to make an user follow the actions other user
>>> (twitter like) I find that many-to-many relationships in app-engine
>>> are not easily supported.
>>>
>>> From my understanding using the tools present in web2py right i would
>>> need to do a lot of processing in memory, an that would hurt
>>> performance greatly.
>>>
>>> The pattern proposed by app store developers uses lists and "parent"
>>> relationship:
>>>
>>> class Message(db.Model):
>>> sender = db.StringProperty()
>>> body = db.TextProperty()
>>>
>>> class MessageIndex(db.Model):
>>> receivers = db.StringListProperty()
>>>
>>> indexes = MessageIndex.all(keys_only = True).filter('receivers = ', user_id)
>>> keys = [k.parent() for k in indexes)
>>> messages = db.get(keys)
>>>
>>> For using that pattern in web2py I would need a method for specifying
>>> the parent of a model instance. Can I specify that relationship using
>>> any method I don't know? If not, would it be hard to implement?
>>>
>>> Thanks in advance!
>
