Thanks a lot Dave.
There isn't a deadline, tale your time :)
Carles
El 25/06/2010, a las 20:42, dlypka <dly...@gmail.com> escribió:
> OK will do - please give me a few days...
>
> On Jun 24, 8:43 pm, Carles Gonzalez <carle...@gmail.com> wrote:
>> 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!
