Django query select distinct by field pairs

Question

I have the field \'submission\' which has a user and a problem. How can I get an SQL search result which will give a list of only one result per user-problem pair?

Model

Answer 1

Try this:

distinct_users_problems = Submission.objects.all().values("user", "problem").distinct()

It will give you a list of dicts like this one:

[{'problem': 1, 'user': 1}, {'problem': 2, 'user': 1}, {'problem': 3, 'user': 1}]

containing all the distinct pairs.

It actually results in your usual SELECT DISTINCT SQL query.