django - ordering queryset by a calculated field

Question

I want to have a model with calculated fields that I can apply sorting on. For example, let\'s say that I have the following model:

class Foo(models.Model):
         


        

Answer 1

If you would not mind some logic duplicaton, then the following will work:

Foo.objects.extra(select={'d_field': 'A - B'}).extra(order_by=['d_field'])