On Mon, 2007-06-04 at 10:11 +0200, Horst Gutmann wrote: > Hi everyone :-) > > I'm currently writing a small app that should store data for registered > users and guests alike in one single model. So I made following model > (simplied) > > class Content(models.Model): > user = models.ForeignKey(User, null=True, blank=True) > > The problem I now face is, that Django seems not to do a LEFT OUTER JOIN > when fetching all the instances of this model when queried with > select_related(), which naturally results in a huge amount of queries (I > guess on query per NOT NULL foreign key).
This is ongoing work as part of the Queryset refactor. It's hard to fix in a general way with the current code, but easy in the redesign. So the "true" answer to your question is "wait a little while". > > My question now is, what options do I have to keep the query count low? > So far I think I have following ones: > > (1) Query without selected related and then fill the content.user fields > manually with a seperate WHERE IN query for the user.ids > > (2) Use something like Martin Fowler's NULL Object pattern and basically > create a user with the ID 0 (or a negative integer if possible) If all guests can be treated as the same object, that is a good solution at the moment. I've used it before with success; although I managed to avoid using any buzzwords like "Martin Fowler" or "pattern" -- you just make a user called "AnonymousFred" and do stuff with that. Regards, Malcolm --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
