fix setting new related model just from dict with pkname

tests/test_foreign_keys.py

@@ -133,6 +133,8 @@ async def test_model_crud():
         assert album1.pk == 1
         assert album1.tracks is None
 
+        await Track.objects.create(album={"id": track.album.pk}, title="The Bird2", position=4)
+
 
 @pytest.mark.asyncio
 async def test_select_related():

tests/test_more_reallife_fastapi.py

@@ -61,13 +61,13 @@ def create_test_database():
 @app.get("/items/", response_model=List[Item])
 async def get_items():
     items = await Item.objects.select_related("category").all()
-    return [item.dict() for item in items]
+    return items
 
 
 @app.post("/items/", response_model=Item)
 async def create_item(item: Item):
-    item = await Item.objects.create(**item.dict())
-    return item.dict()
+    await item.save()
+    return item
 
 
 @app.post("/categories/", response_model=Category)