On 5/7/2009 10:42 AM, overgroove wrote: > I have the following models: > > Customer > Order > Lineitem > > Customers have orders and orders have lineitems. In lineitems there's > a product price and a product quantity. I would like to be able to, > using django querysets and whatever magic I have to do, to annotate > the multiplication of price and quantity in lineitem to the customer. > I know I can do this with raw sql, however, I'd like to do it with > querysets so that I can afterwards apply a filter. I've tried a hack > where I perform some trivial annotation to the customer based on a > lineitem (which gives me the appropriate joins) and then add SUM(price > * quantity) with extra() to the select. However, this column also > gets added to the group by clause, rendering the query useless.
There might be a fancy way to do this in QuerySet, but I don't know how. I personally would just write a custom method on Customer or Order to do this for you, depending on what level of aggregation you need. -- George --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
