Selection from subquery

[Eugene Kovalev]

Right now it is totally impossible to select columns from a subquery.

This is a very simple SQL which Django ORM does not support:

SELECT name, sum(age) as age FROM (
    SELECT name, date, max(age) as age FROM table GROUP BY name, date
) GROUP BY name

Probably, it can look something like this:

subq = Table.objects.values('name', 'date').annotate(age=Max('age'))
result = subq.objects.values('name').annotate(age=Sum('age'))

[Simon Charette]

Duplicate of #24462; Add a new QuerySet operation to use current results as a subquery