python - Django REST 框架 : "This field is required." with required=False and unique_together

Question

我想用 Django REST Framework 保存一个简单的模型。唯一的要求是 UserVote.created_by 在 perform_create() 方法中自动设置。失败并出现以下异常:

{
    "created_by": [
        "This field is required."
    ]
}

我猜这是因为 unique_together 索引。

模型.py:

class UserVote(models.Model):
    created_by = models.ForeignKey(User, related_name='uservotes')
    rating = models.ForeignKey(Rating)

    class Meta:
        unique_together = ('created_by', 'rating')

序列化器.py

class UserVoteSerializer(serializers.ModelSerializer):
    id = serializers.IntegerField(read_only=True)
    created_by = UserSerializer(read_only=True)

    class Meta:
        model = UserVote
        fields = ('id', 'rating', 'created_by')

View .py

class UserVoteViewSet(viewsets.ModelViewSet):
    queryset = UserVote.objects.all()
    serializer_class = UserVoteSerializer
    permission_classes = (IsCreatedByOrReadOnly, )

    def perform_create(self, serializer):
        serializer.save(created_by=self.request.user)

如何在 DRF 中保存我的模型而不需要用户提供 created_by 而是在代码中自动设置此字段？

提前致谢!

Answer 1

我有一个类似的问题，我通过显式创建一个新实例并将其传递给序列化程序来解决它。在 UserVoteViewSet 中，您必须将 perform_create 替换为 create:

 def create(self, request, *args, **kwargs):
    uv = UserVote(created_by=self.request.user)
    serializer = self.serializer_class(uv, data=request.data)
    if serializer.is_valid():
        serializer.save()
        return Response(serializer.data, status=status.HTTP_201_CREATED)
    else:
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)