#25796: annotate() exception if there are same fields name OR in Q
-------------------------------------+-------------------------------------
Reporter: Falldog | Owner: nobody
Type: Bug | Status: closed
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution: invalid
Keywords: annotate | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by jarshwah):
* status: new => closed
* version: 1.8 => master
* resolution: => invalid
Comment:
The problem here is that you're combining two filters together that can't
logically be grouped together. You've got half of a "HAVING" clause and
half of a "WHERE" clause and you're trying to OR them together. This can't
work.
This would work (Maybe you should split these two filter clause):
query.filter(commodity_count=0, Q(name__isnull=False) |
Q(subshipment_set__name__isnull=False))
# or maybe..
query.filter(commodity_count=0).filter(Q(name__isnull=False) |
Q(subshipment_set__name__isnull=False))
But I'm not really sure what you're trying to **do** with your query. Do
you perhaps want to do the name is null checking *before* the Count?
Adding the filtering after the annotation always filters after the result
of annotating. These are different:
{{{
Shipment.objects
.annotate(commodity_count=Count('commodity_set'))
.filter(name__isnull=False)
# different!
Shipment.objects
.filter(name__isnull=False)
.annotate(commodity_count=Count('commodity_set'))
}}}
The first will do the count, and then will remove any with null. The
second will remove any with null and *then* do a count, which is important
when you're trying to filter on the result of the count.
This is *probably* the query you want:
{{{
Shipment.objects
.filter(Q(name__isnull=False) | Q(subshipment__name__isnull=False)) #
WHERE CLAUSE
.annotate(commodity_count=Count('commodity_set')) # count excludes
null names
.filter(commodity_count=0) # inserts HAVING CLAUSE
}}}
Closing this as invalid because you can't combine aggregate filters with
regular filters, but please reopen if I've misinterpreted your query.
--
Ticket URL: <https://code.djangoproject.com/ticket/25796#comment:2>
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