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
36648	"""pk"" exception when using first() on unordered queryset with aggregation does not consider composite pk fields provided separately"	Jacob Walls	Jacob Walls	"Discovered while poking into the source for `first()` that we have a special case for `""pk""` that does not behave equivalently for composite primary key fields specified individually.

A test for `CompositePKAggregateTests`:

The commented out assertion shows the point of the guard -- it should raise a TypeError in most cases of using first() on an unordered queryset, see #33772.

The second assertion shows the exception for `values(""pk"")` -- this does not raise.
The third assertion tries to provide the values for a composite pk separately -- this should not raise... 
{{{#!py
    def test_group_by_guard(self):
        # This assertion passes, only included to demonstrate the behavior.
        # with self.assertRaises(TypeError):
        #     Comment.objects.values(""text"").annotate(max=Max(""id"")).first()
        Comment.objects.values(""pk"").annotate(max=Max(""id"")).first()  # passes
        Comment.objects.values(""tenant"", ""id"").annotate(max=Max(""id"")).first()  # fails
}}}

... but does:
{{{#!py
TypeError: Cannot use QuerySet.first() on an unordered queryset performing aggregation. Add an ordering with order_by().
}}}
"	Bug	closed	Database layer (models, ORM)	5.2	Release blocker	fixed	compositepk		Ready for checkin	1	0	0	0	0	0