Cumulative (running) sum with django orm and postgresql

Question

Is it possible to calculate the cumulative (running) sum using django\'s orm? Consider the following model:

class AModel(models.Model):
    a_number = models         


        

Answer 1

For reference, starting with Django 2.0 it is possible to use the Window function to achieve this result:

AModel.objects.annotate(cumsum=Window(Sum('a_number'), order_by=F('id').asc()))\
              .values('id', 'cumsum').order_by('id', 'cumsum')