Django Token objects update error : django.db.utils.IntegrityError: UNIQUE constraint failed: authtoken_token.user_id

Question

I was using django user class and rest_framework Token class to store the user info and the token. For the same I was using serializers.ModelSerializer class. But when I am making update request(check update method) to update the user info as well as the token that I have, its giving me error.

Here is serializers.py

from rest_framework import serializers
from django.contrib.auth.models import User
from rest_framework.authtoken.views import Token

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ['id', 'username', 'password']

        extra_kwargs = {
            'password' : {
                'write_only':True,
                'required': True
            }
        }
    
    def create(self, validated_data):
        user = User.objects.create_user(**validated_data)
        Token.objects.create(user=user) # create token for the user
        return user

    def update(self, instance, validated_data):
        instance.username = validated_data['username']
        instance.set_password(validated_data['password'])
        instance.save()
        Token.objects.update(user=instance)

        return instance

views.py

class UserViewSet(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer

    permission_classes = [IsAuthenticated, IsOwnerOfObject]
    authentication_classes = (TokenAuthentication,)

urls.py

from django.urls import path, include
from rest_framework.routers import DefaultRouter

router = DefaultRouter()
router.register('users', UserViewSet, basename = 'users')

urlpatterns = [
    path('api/', include(router.urls)),
]

Error :

django.db.utils.IntegrityError: UNIQUE constraint failed: authtoken_token.user_id

This is how I am making the request with the authorisation token in the header field:

Answer 1

What do you want to achieve?

Token.objects.update(user=instance)

It doesn't make any sense. It is update without WHERE clause.

I think that you "want" to do something like this.

Token.objects.filter(user=instance).update(user=instance)

That query does nothing really.

I think that you really want is token invalidation. You must delete the current one and generate new.