i have problem editing my queryset in Django REST framwork. Basically i need to filter my query and return single one, so my DRF view look like this:

class MyModelViewSet(viewsets.ModelViewSet):
    queryset = MyModel.objects.all()
    serializer_class = MyModelSerializer

    def get_queryset(self):
        start = self.kwargs['start']
        end = self.kwargs['end']
        qs, created = MyModel.objects.get_or_create(start=start, end=end)
        return qs

So i return single model instance, but when i try to get access true the DRF web interface i get an error 'MyModel' object has no attribute 'model'

Traceback:

File "/Users/stay-wide-awake/code/env/lib/python3.4/site-packages/django/core/handlers/base.py" in get_response
  132.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Users/stay-wide-awake/code/env/lib/python3.4/site-packages/django/views/decorators/csrf.py" in wrapped_view
  58.         return view_func(*args, **kwargs)
File "/Users/stay-wide-awake/code/env/lib/python3.4/site-packages/rest_framework/viewsets.py" in view
  85.             return self.dispatch(request, *args, **kwargs)
File "/Users/stay-wide-awake/code/env/lib/python3.4/site-packages/rest_framework/views.py" in dispatch
  456.             response = self.handle_exception(exc)
File "/Users/stay-wide-awake/code/env/lib/python3.4/site-packages/rest_framework/views.py" in dispatch
  444.             self.initial(request, *args, **kwargs)
File "/Users/stay-wide-awake/code/env/lib/python3.4/site-packages/rest_framework/views.py" in initial
  359.         self.check_permissions(request)
File "/Users/stay-wide-awake/code/env/lib/python3.4/site-packages/rest_framework/views.py" in check_permissions
  304.             if not permission.has_permission(request, self):
File "/Users/stay-wide-awake/code/asp/src/apps/api2/permission.py" in has_permission
  34.         perms = self.get_required_permissions(request.method, queryset.model)

Exception Type: AttributeError at /api/v2/geo/36.606111,-118.062778|36.578581,-120.291994/
Exception Value: 'MyModel' object has no attribute 'model'

Router and all other parts is OK (tested via prints :))

Will be grateful for any hints.

score:4

Accepted answer

The object received via MyModel.objects.get_or_create(start=start, end=end) is not a queryset hence you are getting this error.

Django's get_or_create() returns a tuple of (object, created) where object is the retrieved or created object and created is a boolean specifying whether a new object was created.

In your get_queryset() method, you are setting queryset qs to this received object when infact its a model object.

get_queryset() should return a queryset and not a model object which you are doing.

You can do something like:

def get_queryset(self):
    start = self.kwargs['start']
    end = self.kwargs['end']
    mymodel_obj, created = MyModel.objects.get_or_create(start=start, end=end)
    return MyModel.objects.filter(id=mymodel_obj.id) # returns a queryset now

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