Query with several filtered annotation on different related objects

[Etienne Chove]

Hello,

This test code fails (inserted in tests/annotations/tests.py) on django 2.0.7.

The first and the second annotation works when then are executed alone... but when executed together, the result differ from alone-executions.

Etienne

    def test_filtered_annotation_several_related_objects(self):
        amazon=Store.objects.get(name='Amazon.com')
        
        # create employees
        Employee(first_name="E1", last_name="E1", store=amazon, age=30, salary=0).save()
        Employee(first_name="E2", last_name="E2", store=amazon, age=70, salary=0).save()
        
        # annotations
        a1 = Count("books", filter=Q(books__pages__gt=400))
        a2 = Count("employee", filter=Q(employee__age__gt=60))
        
        # first annotation
        stores1 = Store.objects.annotate(big_books=a1)
        s1 = stores1.get(pk=amazon.pk)
        self.assertEqual(s1.big_books, 4)

        # second annotation
        stores2 = Store.objects.annotate(old_employee=a2)
        s2 = stores2.get(pk=amazon.pk)
        self.assertEqual(s2.old_employee, 1)

        # together
        stores3 = Store.objects.annotate(big_books=a1, old_employee=a2)
        s3 = stores3.get(pk=amazon.pk)
        self.assertEqual(s3.old_employee, s2.old_employee)
        self.assertEqual(s3.big_books, s1.big_books)

The result is :

======================================================================
FAIL: test_filtered_annotation_several_related_objects (aggregation.tests.NonAggregateAnnotationTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Users\[...]\tests.py", line 627, in test_filtered_annotation_several_related_objects
    self.assertEqual(s3.old_employee, s2.old_employee)
AssertionError: 6 != 1

[Simon Charette]

That's a documented caveat of ​multi-tables annotations.

Duplicate of #10060.