id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
36481	"UpdateQuery.add_update_values always computes ""direct"" variable as True"	Ryan P Kilby	Ryan P Kilby	"For context, I've been messing around with `ForeignObject` in an attempt to use correlated subqueries as a join condition. e.g., defining a `latest_post` relation field that enables queries like `Author.objects.select_related(""latest_post"")`. Given that the relation is based on a subquery, the field is not concrete, and in testing how the queryset API works with this field, I ran into a confusing condition in `QuerySet.update` via the `UpdateQuery.add_update_values` method. In short, [[https://github.com/django/django/blob/5.2.3/django/db/models/sql/subqueries.py#L90|line 90]] computes a `direct` variable that always resolves to true. You can verify how the boolean logic resolves with:

{{{#!python
class UpdateTests(unittest.TestCase):

    def test_direct(self):
        testcases = [
            (True, True),
            (True, False),
            (False, True),
            (False, False),
        ]
        for auto_created, concrete in testcases:
            with self.subTest(auto_created=auto_created, concrete=concrete):
                self.assertTrue(not (auto_created and not concrete) or not concrete)
}}}

This condition should simplify to `not auto_created or concrete or not concrete` to `concrete or not concrete` to `True`. Digging through the blame, direct was previously provided by the model meta's `.get_field_by_name()`, which [[https://github.com/django/django/blob/749d23251bbd6564341405e6f8c1da129b8307e7/django/db/models/options.py#L410-L411|states]] ""direct is True if the field exists on this model"". Without fully understanding the field internals, I assume `direct` should have been replaced with just `field.concrete`. I'm not sure what the intent was for auto-created fields, but whether it's concrete seems to be the actual relevant bit, not whether it's auto-created. "	Bug	closed	Database layer (models, ORM)	5.2	Normal	fixed		Ryan P Kilby	Ready for checkin	1	0	0	0	0	0