def get_with_total(cls):
# запрос, так быстрее
total_output_field = models.DecimalField(max_digits=10,
decimal_places=2)
total_expr = E(F('amount') * F('product__price'),
output_field=total_output_field)
return cls.objects.annotate(total=total_expr)
def order_value(self):
queryset = self.salesorderitem_set.aggregate(order_value=Sum(
E(F('unit_price') * F('quantity_ordered'),
output_field=models.DecimalField())), )
return queryset['order_value'] or 0
def get_with_total(cls):
total_output_field = models.DecimalField(max_digits=10,
decimal_places=2)
total_expr = E(F('qty') * F('products__price'),
output_field=total_output_field)
return cls.objects.annotate(total=total_expr)