django-generic-aggregation 0.3.0

annotate() and aggregate() for generically related data

annotate() and aggregate() for generically-related data. also a handy function for filtering GFK-model querysets.

the use of annotate() and aggregate() require a GenericRelation.

Examples

You want the most commented on blog entries:

>>> from django.contrib.comments.models import Comment
>>> from django.db.models import Count
>>> from blog.models import BlogEntry
>>> from generic_aggregation import generic_annotate

>>> annotated = generic_annotate(BlogEntry.objects.all(), Comment, Count('comments__id'))

>>> for entry in annotated:
...    print entry.title, entry.score

The most popular 5
The second best 4
Nobody commented 0

You want to figure out which items are highest rated:

from django.db.models import Sum, Avg

# assume a Food model and a generic Rating model
apple = Food.objects.create(name='apple')

# create some ratings on the food
Rating.objects.create(content_object=apple, rating=3)
Rating.objects.create(content_object=apple, rating=5)
Rating.objects.create(content_object=apple, rating=7)

>>> aggregate = generic_aggregate(Food, Rating, Sum('ratings__rating'))
>>> print aggregate
15

>>> aggregate = generic_aggregate(Food, Rating.objects.all(), Avg('ratings__rating'))
>>> print aggregate
5

You want to only display ratings for comments made on a given site:

>>> from django.contrib.comments.models import Comment
>>> from generic_aggregation import generic_filter
>>> ratings = Rating.objects.all() # <--- grab all the ratings
>>> comments = Comment.objects.filter(site=Site.objects.get_current())
>>> siteified_ratings = generic_filter(ratings, comments)

Check the tests - there are more examples there. Tested with postgres & sqlite