Django: Query using group by and count

To group the results by a certain field and count the number of matches in each row, use values() to group and annotate(Count()) to count.

view sourceprint?

01.from django.db.models import Count

02. 

03.brands = Product.objects.get_everything_for_category(category)

04. 

05.# Make it group by manufacturers and count the number of products for each brand betwen $50 and $100

06.brands = brands.filter(price__gte = 50, price__lte = 100)

07. 

08.# http://docs.djangoproject.com/en/dev/topics/db/aggregation/#values

09.brands = brands.values('manufacturer').annotate(Count('manufacturer')).order_by('manufacturer')

To access the information within "brands":

view sourceprint?

1.{% for brand in brands %}

2.  <li>{{brand.manufacturer}} ({{brand.manufacturer__count}})</li>

3.{% endfor %}