Django ORM - 按子查询分组和注释

Question

What I'm trying to do in Django ORM is the following:

• Group by user
• Sum the profits
• Annotate with the latest status of that user

My queryset looks like this:

Sales.objects.values('user').annotate(
    profits = Sum('profit'),
    status = Subquery(Status.objects.filter(username=OuterRef('user')).order_by('-date').values('status')[:1]
).order_by()

If I inspect the SQL query of this queryset, I can see that the status field is added to the group by clause. But this query cannot be executed. How can I prevent Django from adding this to the group by clause? Because the rest of the query just works fine.

Answer 1

Start with a User object rather than a Sales object.

I don't know your model structure, so this is a bit of a guess.

User.objects.annotate(
    profits = Sum('sales__profit'),
    status = Subquery(Status.objects.filter(username=OuterRef('user')).order_by('-date').values('status')[:1]).order_by()