Django rest framework:UniqueValidator copare the field convert to upper case

Question

I can save the mac_address to upper in database
And the mac_address value should be unique in database

But if the client send me a lower case json like {"mac_address":'aa:bb:cc:dd:eE'}
and my database already had mac_address with 'AA:BB:CC:DD:EE'
But client still got 201 created success
Why wouldn't my UniqueValidator work ??
Please help me find out

views.py

I try ListCreateAPIView and APIView
Both can't work well I think the problem is UniqueValidator part

I find the document use validate_<field_name> But My code not work

class DataList(generics.ListCreateAPIView):
    queryset = Data.objects.all()
    serializer_class = DataSerializer

    def perform_create(self, serializer):
        mac_address = self.request.data['mac_address'].upper()
        serializer.save(mac_address=mac_address, datetime=datetime.datetime.now(pytz.utc))
class DataList(APIView):
    def post(self, request, format=None):
        serializer = DataSerializer(data=request.data)
        if serializer.is_valid():
            mac_address = request.data['mac_address'].upper()
            serializer.save(mac_address=mac_address, datetime=datetime.datetime.utcnow().replace(tzinfo=pytz.utc))
            return Response(serializer.data, status=status.HTTP_201_CREATED)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

And the serialize validator needs to convert to lower case first then query the database.

class DataSerializer(serializers.ModelSerializer):
    datetime = ReadOnlyField()
    mac_address = CharField(max_length=50,
    validators=[UniqueValidator(queryset=Data.objects.all())]
)
    def validate_mac_address(self,value):
        return value.upper()

Answer 1

Your validator should be doing the actual validation:

class DataSerializer(serializers.ModelSerializer):
    datetime = ReadOnlyField()
    mac_address = CharField(max_length=50)

    def validate_mac_address(self,value):
        if Data.objects.filter(mac_address=value.upper()).exists():
            raise serializers.ValidationError("MAC address should be unique")
        return value.upper()

Answer 2

define valid_email method into your serializer

class DataSerializer(serializers.ModelSerializer):

    email = CharField(
        max_length=255,
        validators=[UniqueValidator(queryset=BlogPost.objects.all())]
    )

    // your content and other stuff goes here

    def valid_email(self,value):
        return value.lower()