fix: Use proper column name instead of attname (#573)

fix: Use proper column name instead of attname

CHANGES.rst

@@ -9,6 +9,7 @@ To be released
 - Add support for `Python 3.12` (GH-#545)
 - Drop support for `Python 3.7` (GH-#545)
 - Swedish translation (GH-#561)
+- Use proper column name instead of attname (GH-#573)
 
 4.3.1 (2022-11-15)
 ------------------

model_utils/managers.py

@@ -194,7 +194,7 @@ def instance_of(self, *models):
             where_queries.append('(' + ' AND '.join([
                 '"{}"."{}" IS NOT NULL'.format(
                     model._meta.db_table,
-                    field.attname,  # Should this be something else?
+                    field.column,
                 ) for field in model._meta.parents.values()
             ]) + ')')
 

tests/models.py

@@ -67,6 +67,12 @@ class InheritanceManagerTestChild3(InheritanceManagerTestParent):
         parent_link=True, on_delete=models.CASCADE)
 
 
+class InheritanceManagerTestChild3_1(InheritanceManagerTestParent):
+    parent_ptr = models.OneToOneField(
+        InheritanceManagerTestParent, db_column="custom_parent_ptr",
+        parent_link=True, on_delete=models.CASCADE)
+
+
 class InheritanceManagerTestChild4(InheritanceManagerTestParent):
     other_onetoone = models.OneToOneField(
         InheritanceManagerTestParent, related_name='non_inheritance_relation',

tests/test_managers/test_inheritance_manager.py

@@ -5,6 +5,7 @@
     InheritanceManagerTestChild1,
     InheritanceManagerTestChild2,
     InheritanceManagerTestChild3,
+    InheritanceManagerTestChild3_1,
     InheritanceManagerTestChild4,
     InheritanceManagerTestGrandChild1,
     InheritanceManagerTestGrandChild1_2,
@@ -141,6 +142,7 @@ def test_manually_specifying_parent_fk_including_grandchildren(self):
             'inheritancemanagertestchild1',
             'inheritancemanagertestchild2',
             'manual_onetoone',  # this was set via parent_link & related_name
+            'inheritancemanagertestchild3_1',
             'child4_onetoone',
         ]
         self.assertEqual(set(results.subclasses),
@@ -256,7 +258,9 @@ def test_selecting_all_subclasses_specifically_grandchildren(self):
         objs = InheritanceManagerTestParent.objects.select_subclasses().order_by('pk')
         objsmodels = InheritanceManagerTestParent.objects.select_subclasses(
             InheritanceManagerTestChild1, InheritanceManagerTestChild2,
-            InheritanceManagerTestChild3, InheritanceManagerTestChild4,
+            InheritanceManagerTestChild3,
+            InheritanceManagerTestChild3_1,
+            InheritanceManagerTestChild4,
             InheritanceManagerTestGrandChild1,
             InheritanceManagerTestGrandChild1_2).order_by('pk')
         self.assertEqual(set(objs.subclasses), set(objsmodels.subclasses))
@@ -278,6 +282,7 @@ def test_selecting_all_subclasses_specifically_children(self):
         models = (InheritanceManagerTestChild1,
                   InheritanceManagerTestChild2,
                   InheritanceManagerTestChild3,
+                  InheritanceManagerTestChild3_1,
                   InheritanceManagerTestChild4,
                   InheritanceManagerTestGrandChild1,
                   InheritanceManagerTestGrandChild1_2)
@@ -426,6 +431,12 @@ def test_limit_to_specific_subclass(self):
 
         self.assertEqual([child3], list(results))
 
+    def test_limit_to_specific_subclass_with_custom_db_column(self):
+        item = InheritanceManagerTestChild3_1.objects.create()
+        results = InheritanceManagerTestParent.objects.instance_of(InheritanceManagerTestChild3_1)
+
+        self.assertEqual([item], list(results))
+
     def test_limit_to_specific_grandchild_class(self):
         grandchild1 = InheritanceManagerTestGrandChild1.objects.get()
         results = InheritanceManagerTestParent.objects.instance_of(InheritanceManagerTestGrandChild1)