Django Annotate

Question

Is there a way to annotate by a field within the model and another model object?

I have a Restaurant model object that I want to annotate a 'weight' field. My criteria is number of reviews + number of visits. I would like to do something like this:

weighted = Restaurant.objects.annotate(
    weight = Count('reviews') + num_visits??).order_by('weight')

The num_visits part is giving an error and I'm not sure how to correct this. num_visits is a field in the Restaurant model. Any help is appreciated.

Answer 1

I think you'll need something like this

qs = Restaurant.objects.annotate(weight=Count('reviews') + F('num_visits'))
weighted = qs.order_by('weight')

It's making use of an F expression .