https://github.com/coleifer/django-generic-aggregation

annotate() and aggregate() for generically-related data.
https://github.com/coleifer/django-generic-aggregation

Last synced: 9 months ago
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annotate() and aggregate() for generically-related data.

• Host: GitHub
• URL: https://github.com/coleifer/django-generic-aggregation
• Owner: coleifer
• License: mit
• Created: 2010-05-31T18:56:29.000Z (over 15 years ago)
• Default Branch: master
• Last Pushed: 2023-06-13T18:30:33.000Z (over 2 years ago)
• Last Synced: 2025-03-30T16:44:39.986Z (10 months ago)
• Language: Python
• Homepage: http://django-generic-aggregation.readthedocs.org
• Size: 48.8 KB
• Stars: 71
• Watchers: 6
• Forks: 9
• Open Issues: 2
• Metadata Files:
  • Readme: README.rst
  • Changelog: History.md
  • License: LICENSE

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README

          
==========================

django-generic-aggregation

==========================

annotate() and aggregate() for generically-related data.  also a handy function

for filtering GFK-model querysets.

Use django's `GenericRelation `_ where possible,

as this can make the queries generated more efficient by using a JOIN rather

than a subquery.

installation

------------

::

    # install from pypi

    pip install django-generic-aggregation

    

    # or install via git

    pip install -e git+git://github.com/coleifer/django-generic-aggregation.git#egg=generic_aggregation

examples

--------

The examples below assume the following simple models:

::

    class Rating(models.Model):

        rating = models.IntegerField()

        object_id = models.IntegerField()

        content_type = models.ForeignKey(ContentType)

        content_object = GenericForeignKey(ct_field='content_type', fk_field='object_id')

    

    class Food(models.Model):

        name = models.CharField(max_length=50)

        ratings = generic.GenericRelation(Rating) # reverse generic relation

You want to figure out which items are highest rated (generic_annotate)

::

    from django.db.models import Avg

    

    food_qs = Food.objects.filter(name__startswith='a')

    generic_annotate(food_qs, Rating, Avg('ratings__rating'))

    

    # you can mix and match queryset / model

    generic_annotate(food_qs, Rating.objects.all(), Avg('ratings__rating'))

You want the average rating for all foods that start with 'a' (generic_aggregate)

::

    food_qs = Food.objects.filter(name__startswith='a')

    generic_aggregate(food_qs, Rating, Avg('ratings__rating'))

You want to only display ratings for foods that start with 'a' (generic_filter)

::

    food_qs = Food.objects.filter(name__startswith='a')

    generic_filter(Rating.objects.all(), food_qs)

documentation

-------------

https://django-generic-aggregation.readthedocs.io/