Add a way to have an aggregate() result as a queryset
|Reported by:||Malcolm Tredinnick||Owned by:||nobody|
|Component:||Database layer (models, ORM)||Version:|
|Has patch:||no||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
If one is trying to construct a complex queryset, involving nesting other querysets, there's currently no way to include the results of an
aggregate() call. For example, consider
class Item(models.Model): name = models.CharField(max_length=10)
If I want to include the number of Items in some other queryset, such as
We can't write item_count (which would be
Items.objects.aggregate(Count("id"))) as an inner queryset here, since the
aggregate() call returns a dictionary, not a queryset.
The return value of
aggregate() is fine, but this ticket is about adding a version that does return a queryset. Right now, there's no way to fake this with
annotate(...).values(...) since that always introduces a
GROUP BY clause and the whole point is not to group by anything.
Not sure whether adding a parameter to
aggregate() is the right idea, or adding something to the
annotate() route to specify "no grouping whatsoever". This is all 1.2 timeframe stuff, but it's something to think about.
Change History (7)
comment:1 Changed 8 years ago by
|Patch needs improvement:||unset|
|Triage Stage:||Unreviewed → Accepted|