Django Rest Framework Field Validation Issue - python-3.x

Question

My subscription view is located inside of UserViewSet. I'm wondering why I'm getting
IntegrityError at /api/users/1/subscribe/
new row for relation "users_subscription" violates check constraint "prevent_self_subscription"
DETAIL: Failing row contains (11, 1, 1).
instead of proper json answer. Somehow SubscriptionSerializer field validation doesnt wish to work. Any thoughts?
models.py
class Subscription(models.Model):
user = models.ForeignKey(
User, related_name='subscriber',
on_delete=models.CASCADE)
author = models.ForeignKey(
User, related_name='subscribing',
on_delete=models.CASCADE)
class Meta:
constraints = [
models.UniqueConstraint(
fields=('user', 'author'),
name='unique_subscription'
),
models.CheckConstraint(
check=~models.Q(user=models.F('author')),
name='prevent_self_subscription'
)
]
serializers.py
class SubscriptionSerializer(serializers.ModelSerializer):
user = serializers.PrimaryKeyRelatedField(
read_only=True, default=serializers.CurrentUserDefault())
class Meta:
model = models.Subscription
fields = ('author', 'user', )
validators = [
serializers.UniqueTogetherValidator(
queryset=models.Subscription.objects.all(),
fields=['author', 'user', ]
)
]
def create(self, validated_data):
return models.Subscription.objects.create(
user=self.context.get('request').user, **validated_data)
def validate_subscribing(self, value):
if self.context.get('request').user == value:
raise serializers.ValidationError(
'You cant subscribe to yourself!')
return value
views.py
#action(['post'], detail=True)
#permission_classes(permissions.IsAuthenticated)
def subscribe(self, request, *args, **kwargs):
author = get_object_or_404(models.User, id=kwargs['id'])
data = request.data.copy()
data.update({'author': author.id})
serializer = serializers.SubscriptionSerializer(
data=data, context={'request': request})
if request.method == 'POST':
serializer.is_valid(raise_exception=True)
serializer.save()
return Response(
status=status.HTTP_201_CREATED,
data=self.get_serializer(author).data)

Answer 1

It was the wrong method name, field name is 'author' and method was validate_subscribing() instead of validate_author().