Output Django queryset as JSON

Question

I want to serialize my queryset, and I want it in a format as this view outputs:

class JSONListView(ListView):     queryset = Users.objects.all()      def get(self, request, *args, **kwargs):         return HttpResponse(json.dumps({'data': [['bar','foo','bar','foo'],['foo','bar','foo','bar']]}, indent=4), content_type='application/json') 

I simply don't know how to output the queryset instead of the manual data in the example.

I've tried

json.dumps({"data": self.get_queryset()}) 

and

serializers.serialize("json", {'data': self.get_queryset()}) 

but it wont work. What am I doing wrong? Do I need to make a custom JSON Encoder?

Answer 1

You can use JsonResponse with values. Simple example:

from django.http import JsonResponse  def some_view(request):     data = list(SomeModel.objects.values())  # wrap in list(), because QuerySet is not JSON serializable     return JsonResponse(data, safe=False)  # or JsonResponse({'data': data}) 

Or another approach with Django's built-in serializers:

from django.core import serializers from django.http import HttpResponse  def some_view(request):     qs = SomeModel.objects.all()     qs_json = serializers.serialize('json', qs)     return HttpResponse(qs_json, content_type='application/json') 

In this case result is slightly different (without indent by default):

[     {         "model": "some_app.some_model",         "pk": 1,         "fields": {             "name": "Elon",             "age": 48,             ...         }     },     ... ] 

I have to say, it is good practice to use something like marshmallow to serialize queryset.

...and a few notes for better performance:

• use pagination if your queryset is big;
• use objects.values() to specify list of required fields to avoid serialization and sending to client unnecessary model's fields (you also can pass fields to serializers.serialize);