diff options
| -rw-r--r-- | tests/model_inheritance_regress/tests.py | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/tests/model_inheritance_regress/tests.py b/tests/model_inheritance_regress/tests.py index 8f741bbb7f..98216dbc84 100644 --- a/tests/model_inheritance_regress/tests.py +++ b/tests/model_inheritance_regress/tests.py @@ -8,6 +8,7 @@ from operator import attrgetter from django import forms from django.test import TestCase +from django.utils.unittest import expectedFailure from .models import (Place, Restaurant, ItalianRestaurant, ParkingLot, ParkingLot2, ParkingLot3, Supplier, Wholesaler, Child, SelfRefParent, @@ -422,3 +423,19 @@ class ModelInheritanceTest(TestCase): form = ProfileForm({'username': "user_with_profile", 'extra': "hello"}, instance=p) self.assertTrue(form.is_valid()) + + def test_inheritance_joins(self): + # Test for #17502 - check that filtering through two levels of + # inheritance chain doesn't generate extra joins. + qs = ItalianRestaurant.objects.all() + self.assertEqual(str(qs.query).count('JOIN'), 2) + qs = ItalianRestaurant.objects.filter(name='foo') + self.assertEqual(str(qs.query).count('JOIN'), 2) + + @expectedFailure + def test_inheritance_values_joins(self): + # It would be nice (but not too important) to skip the middle join in + # this case. Skipping is possible as nothing from the middle model is + # used in the qs and top contains direct pointer to the bottom model. + qs = ItalianRestaurant.objects.values_list('serves_gnocchi').filter(name='foo') + self.assertEqual(str(qs.query).count('JOIN'), 1) |