Django Rest Serializer Breaks When Data Exists

Question

I have this model:

class MyModel(User):
    #others fields

and this serializer:

class MySerializer(serializers.ModelSerializer):
    class Meta:
        model = MyModel
        fields = ('username', 'password', 'some_field')

I get data from ajax to make a login, and I process it like this:

serializer = MySerializer(data=request.DATA)
print(serializer.is_valid())

Problem: When sending any data, my serializer works, but when mine username field, which should be unique as User modeldescribed, matches one in the database, serialization becomes invalid, so serializer.is_valid()return False

Why? I can not create a serialization object with data that must be unique and already exist in the database?

Answer 1

ModelSerializer, . Serializer.

REST