Serialize queryset in Django rest framework
Question:
I am trying to serialize a collection of objects. I have define the following view method:
@csrf_exempt
def venue_list(request, user_id):
"""
Check that the user is requesting his own venues.
"""
profile = get_profile_for_user_if_match(request.user, user_id)
if profile is None:
return HttpResponse(status=status.HTTP_401_UNAUTHORIZED)
venues = profile.venue_set.all()
serializer = VenueSerializer(venues)
return JSONResponse(serializer.data)
It receives a user_id
parameter which is used to determine if the user has permissions to access the data, then it gets the set of objects to be returned, but it doesn’t work.
It is trying to serialize the set directly, instead of the object inside it, so its throwing this traceback:
Traceback:
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
111. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/django/views/decorators/csrf.py" in wrapped_view
57. return view_func(*args, **kwargs)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/wsgi/openshift/business/restful/views/venueViews.py" in venue_list
22. return JSONResponse(serializer.data)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/serializers.py" in data
572. self._data = self.to_native(obj)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/serializers.py" in to_native
351. value = field.field_to_native(obj, field_name)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/fields.py" in field_to_native
336. return super(WritableField, self).field_to_native(obj, field_name)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/fields.py" in field_to_native
207. value = get_component(value, component)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/fields.py" in get_component
58. val = getattr(obj, attr_name)
Exception Type: AttributeError at /business/api/venues/1
Exception Value: 'QuerySet' object has no attribute 'name'
How can I make this properly?
Thanks.
Answers:
To serialize a queryset or list of objects instead of a single object instance, you should pass the many=True
flag when instantiating the serializer. So in your case try this:
...
venues = profile.venue_set.all()
serializer = VenueSerializer(venues, many=True)
...
I am trying to serialize a collection of objects. I have define the following view method:
@csrf_exempt
def venue_list(request, user_id):
"""
Check that the user is requesting his own venues.
"""
profile = get_profile_for_user_if_match(request.user, user_id)
if profile is None:
return HttpResponse(status=status.HTTP_401_UNAUTHORIZED)
venues = profile.venue_set.all()
serializer = VenueSerializer(venues)
return JSONResponse(serializer.data)
It receives a user_id
parameter which is used to determine if the user has permissions to access the data, then it gets the set of objects to be returned, but it doesn’t work.
It is trying to serialize the set directly, instead of the object inside it, so its throwing this traceback:
Traceback:
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
111. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/django/views/decorators/csrf.py" in wrapped_view
57. return view_func(*args, **kwargs)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/wsgi/openshift/business/restful/views/venueViews.py" in venue_list
22. return JSONResponse(serializer.data)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/serializers.py" in data
572. self._data = self.to_native(obj)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/serializers.py" in to_native
351. value = field.field_to_native(obj, field_name)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/fields.py" in field_to_native
336. return super(WritableField, self).field_to_native(obj, field_name)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/fields.py" in field_to_native
207. value = get_component(value, component)
File "/Users/mariopersonal/Documents/dev/offers/project/offers/venv/lib/python2.7/site-packages/rest_framework/fields.py" in get_component
58. val = getattr(obj, attr_name)
Exception Type: AttributeError at /business/api/venues/1
Exception Value: 'QuerySet' object has no attribute 'name'
How can I make this properly?
Thanks.
To serialize a queryset or list of objects instead of a single object instance, you should pass the many=True
flag when instantiating the serializer. So in your case try this:
...
venues = profile.venue_set.all()
serializer = VenueSerializer(venues, many=True)
...