Django Rest Framework, filter by name

Question

I'm trying to create a filter by username, but django nonstop requires id from me. What is repair here?

class FavoriteList(generics.ListCreateAPIView):
    permission_classes = [permissions.IsAuthenticatedOrReadOnly, IsCurrentUserOwnerOrHidden]
    queryset = Favorite.objects.all()
    serializer_class = FavoritesSerializer
    name = 'favorite-list'

def perform_create(self, serializer):
    serializer.save(owner=self.request.user)

def filter_queryset(self, queryset):
    owner_name = self.request.query_params.get('owner', None)
    if owner_name is not None:
        queryset = queryset.filter(owner=owner_name)
    return queryset

localhost/favorite?owner=1 is working but loclahost/favorite?owner=admin don't

Answer 1

It works that way because .filter method for ForeignKey searches by id. To search by username field you have to use proper lookup:

queryset.filter(owner__username=owner_name)

You can separate that values or I might suggest smart try/except:

def filter_queryset(self, queryset):
    owner_name = self.request.query_params.get('owner', None)
    if owner_name is not None:

        try:
            owner_id = int(owner_name)
        except ValueError:
            owner_id = None

        if owner_id:
            queryset = queryset.filter(owner=owner_id)
        else:
            queryset = queryset.filter(owner__username=owner_name)

    return queryset

With above solution you can pass either object's id or username attribute as a GET parameter.