Fix joining with self by reverse-foreign-key for filtering and annota…

…tion (#333)

CHANGELOG.rst

@@ -6,6 +6,7 @@ Changelog
 -------
 * Fixed invalid ``var IN ()`` SQL generated using ``__in=`` and ``__not_in`` filters.
 * Fix bug with order_by on nested fields
+* Fix joining with self by reverse-foreign-key for filtering and annotation
 
 0.15.20
 ------

tests/test_relations.py

@@ -192,6 +192,33 @@ async def test_self_ref(self):
         self.assertEqual(await root2.full_hierarchy__async_for(), ROOT_TEXT)
         self.assertEqual(await root2.full_hierarchy__fetch_related(), ROOT_TEXT)
 
+    async def test_self_ref_filter_by_child(self):
+        self.maxDiff = None
+        root = await Employee.create(name="Root")
+        await Employee.create(name="1. First H1", manager=root)
+        await Employee.create(name="2. Second H1", manager=root)
+
+        root2 = await Employee.get(team_members__name="1. First H1")
+        self.assertEqual(root.id, root2.id)
+
+    async def test_self_ref_filter_both(self):
+        self.maxDiff = None
+        root = await Employee.create(name="Root")
+        await Employee.create(name="1. First H1", manager=root)
+        await Employee.create(name="2. Second H1", manager=root)
+
+        root2 = await Employee.get(name="Root", team_members__name="1. First H1")
+        self.assertEqual(root.id, root2.id)
+
+    async def test_self_ref_annotate(self):
+        self.maxDiff = None
+        root = await Employee.create(name="Root")
+        await Employee.create(name="1. First H1", manager=root)
+        await Employee.create(name="2. Second H1", manager=root)
+
+        root_ann = await Employee.get(name="Root").annotate(num_team_members=Count("team_members"))
+        self.assertEqual(root_ann.num_team_members, 2)
+
     async def test_prefetch_related_fk(self):
         tournament = await Tournament.create(name="New Tournament")
         await Event.create(name="Test", tournament_id=tournament.id)

tortoise/query_utils.py

@@ -48,9 +48,7 @@ def _get_joins_for_related_field(
 ) -> List[Tuple[Table, Criterion]]:
     required_joins = []
 
-    related_table = (
-        related_field.model_class._meta.basetable
-    )  # .as_(f"{table.get_table_name()}__{related_field_name}")
+    related_table: Table = related_field.model_class._meta.basetable
     if isinstance(related_field, ManyToManyFieldInstance):
         through_table = Table(related_field.through)
         required_joins.append(
@@ -68,6 +66,8 @@ def _get_joins_for_related_field(
             )
         )
     elif isinstance(related_field, BackwardFKRelation):
+        if table == related_table:
+            related_table = related_table.as_(f"{table.get_table_name()}__{related_field_name}")
         required_joins.append(
             (
                 related_table,