How to serialize Django queryset.values() into json?

Question:

I have a model that has many fields, however for this problem I only need 3 of those fields. When I try to serialize a .values set I get an exception:

‘dict’ object has no attribute ‘_meta’

This is my code:

queryset = myModel.objects.filter(foo_icontains=bar).values('f1', 'f2', 'f3')
serialized_q = serializers.serialize('json', queryset, ensure_ascii=False)
Asked By: bash-

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Source

Answers:

Django serializers can only serialize queryset, values() does not return queryset rather ValuesQuerySet object. So, avoid using values(). Rather, specifiy the fields you wish to use in values(), in the serialize method as follows:

Look at this SO question for example

objectQuerySet = ConventionCard.objects.filter(ownerUser = user)
data = serializers.serialize('json', list(objectQuerySet), fields=('fileName','id'))

Instead of using objectQuerySet.values('fileName','id'), specify those fields using the fields parameter of serializers.serialize() as shown above.

Answered By: Davor Lucic

Make list from objectQuerySet:

data_ready_for_json = list( ConventionCard.objects.filter(ownerUser = user).values('fileName','id') )
Answered By: Max

Just cast to dict every item and create json with json.dumps:

json.dumps([dict(item) for item in SomeModel.objects.all().values('id', 'title')])
Answered By: Pavel Patrin

As other people have said, Django’s serializers can’t handle a ValuesQuerySet. However, you can serialize by using a standard json.dumps() and transforming your ValuesQuerySet to a list by using list(). If your set includes Django fields such as Decimals, you will need to pass in DjangoJSONEncoder. Thus:

import json
from django.core.serializers.json import DjangoJSONEncoder

queryset = myModel.objects.filter(foo_icontains=bar).values('f1', 'f2', 'f3')
serialized_q = json.dumps(list(queryset), cls=DjangoJSONEncoder)
Answered By: Andre Gregori

My solution, It’s work fine

from django.core.serializers import serialize
import json

permission_list = Permission.objects.all().order_by('-id')
permission_serialize= json.loads(serialize('json', permission_list))
return JsonResponse({'data': permission_serialize})
Answered By: Ashish Sondagar

Try this:

queryset = myModel.objects.filter(foo_icontains=bar)
serialized_q = serializers.serialize(queryset, many = True)
Answered By: Ratan Sen