[Fixed]-Filter a django QuerySet with the query from another QuerySet: Possible?

How about something along these lines:

Thing.objects.filter(field__in=Another_Thing.object.filter())

Django will do query and subquery.

Many year after I found a solution.

You can use the __dict__ prop from you queryset. For instance:

o = Model.objects.filter(arg=param)
o2 = Model.objects.all()
o2.query.__dict__ = o.query.__dict__
o2.filter(arg2=param2)

o2 will now is filtered by arg and arg2!

I used this to pass a ModelChoiceField filter to django-jet autocomplete views (fork at https://github.com/paulorsbrito/django-jet).

Hope this helps someone in trouble.

As far as I can tell from looking through the QuerySet and Query modules, Django doesn’t keep a running record of the arguments you send into a queryset. It translates everything directly into lower level query fragments then discards the tokens you’ve given it. Thus, figuring out how a queryset has been filtered without prior knowledge is a non-trivial task.

You could do it manually by hacking together something like the following:

q0 = Thing.objects.all()
filter_kwargs = {'x': y}
fq0 = q0.filter(**filter_kwargs)
fq0.saved_filter_kwargs = filter_kwargs

##### snip #####

fq1 = q1.filter(**fq0.saved_kwargs)

Kind of nasty though. Probably better to try solving this problem in a different way. I’d recommend you post another question and include what you’re trying to achieve in the big picture, and we might be able to help you come up with a better architecture.