It seems like it would make more sense to do something like: TaggedItem.objects.filter(book__writer="Dostoevsky")
Unfortunately it looks like this constructs faulty SQL (the join statement in particular), although it appears like it _should_ work. Just try TaggedItem.objects.filter(alskdfjladf='dog') and you'll see that it tells you that books (among other generic relations made by TaggedItem) is one of the fields it suggests to span across. Going to post a separate question about this after I try to see if this topic has been discussed in these groups, but I'd say this is the cleanest and most intuitive approach. On May 28, 9:53 am, "Jonathan Buchanan" <[EMAIL PROTECTED]> wrote: > On 5/28/07, Bram - Smartelectronix <[EMAIL PROTECTED]> wrote: > > > > > > > Hi there, > > > Say I have: > > > class TaggedItem(models.Model): > > """A tag on an item.""" > > tag = models.SlugField() > > content_type = models.ForeignKey(ContentType) > > object_id = models.PositiveIntegerField() > > > content_object = models.GenericForeignKey() > > > class Meta: > > ordering = ["tag"] > > > def __str__(self): > > return self.tag > > > class Book(models.Model): > > writer = models.ForeignKey(User) > > tags = models.GenericRelation(TaggedItem) > > > How do I get all Tags for books by Dostoevsky ? :-) > > > TaggedItem.objects.filter(content_type=ContentType.objects.get_for_model(Book), > > content_object__writer="Dostoevsky") > > > ...doesn't work... And > > > TaggedItem.objects.filter(content_type=ContentType.objects.get_for_model(Book), > > object_id__in=[ book.id for book in > > Book.objects.filter(writer="Dostoevsky")]) > > > is pretty bad. > > > Should I be looking at extra( ) or is there a smarter way to go about this? > > > - bram > > I've just implemented something like this in django-tagging, but it > feels like a massive hack: > > Check out the usage_for_model method > inhttp://django-tagging.googlecode.com/svn/trunk/models.py > > It starts with a basic query template which will retrieve tags and > usage counts for a particular model, taking a dictionary of field > lookups as an optional argument. If this is provided, some of Django's > query generation internals are used to generate required JOIN and > WHERE statements to restrict the tags returned to a subset of the > model. > > If anyone reading that immediately thinks "there's a much cleaner way > to do that with the DB API, yuo buffoon", I'm all ears! :) > > Jonathan. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
