On Wed, Oct 7, 2009 at 1:13 PM, Paddy Joy <[email protected]> wrote: > > Can anyone help out with the following aggregation clause? I have an > invoice and invoice_item models as shown. > > class Invoice(models.Model): > > customer = models.ForeignKey(Customer) > payments_received = models.FloatField(default=0) > > class Invoice_Item(models.Model): > > invoice = models.ForeignKey('Invoice') > sub_total = models.DecimalField(blank=True, null=True, > max_digits=9, decimal_places=2) > > I create one invoice with 2 items > > i = Invoice(customer=c, payments_received=260) > i.save() > > it = Invoice_Item(invoice=1, sub_total=200) > it.save() > it = Invoice_Item(invoice=1, sub_total=60) > it.save() > > > When performing an aggregate with one Sum the Sum of payments_received > field is correct > >>>> account_balance = >>>> Invoice.objects.filter(customer=c).aggregate(Sum('payments_received')) >>>> account_balance > {'payments_received__sum': 260.0} > > However when I add an additional item to the aggregate clause the > payments_received is doubled. > >>>> account_balance = >>>> Invoice.objects.filter(customer=c).aggregate(Sum('invoice_item__sub_total'), >>>> Sum('payments_received')) >>>> account_balance > {'payments_received__sum': 520.0, 'invoice_item__sub_total__sum': > Decimal("260.00")} > > I expected the payments_received sum to always stay the same, is my > understanding of aggregation flawed?
You've discovered is ticket #10060. It's a nasty bug that won't be easy to solve - see the ticket for details. For the moment, the workaround is to do two queries rather than one. Yours Russ Magee %-) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
