Django SUM Query?
Solution 1:
Update: The following incorporates the ISNULL aspect of the original query:
from django.db.models import Sum
ModelName.objects.filter(field_name__isnull=True).aggregate(Sum('field_name'))
# returns {'field_name__sum': 1000} for example
You're looking for the Sum aggregation function, which works as follows:
ModelName.objects.aggregate(Sum('field_name'))
See: https://docs.djangoproject.com/en/dev/ref/models/querysets/#sum