Django to_representation和filter_fields err: TypeError：'Meta.fields‘

Question

目标:能够向filter_fields添加_id属性

我试图将名为title的属性的值存储在一个名为_id的属性中，该属性与_id输入相同，只是小写，没有空格，但我尝试过实例化它的to_representation()。

当我试图将_id添加到我的filter_fields时，我在下面得到错误，删除它并运行它，但是我需要属性_id

filter_fields = ('title', '_id',) <--- the _id cause the err

TypeError: 'Meta.fields' contains fields that are not defined on this FilterSet: _id

models.py

class Portfolio(models.Model):
    created_at = models.DateTimeField()
    title = models.CharField(max_length=255)
    description = models.TextField()
    link = models.CharField(max_length=300)
    img = models.CharField(max_length=255)

    def __str__(self):
        return self.title

这里是我试图通过重写serializer.py来实例化它的地方

class PortfolioSerializer(serializers.ModelSerializer):
    class Meta:
        model = Portfolio
        fields = ('created_at', 'title', 'description', 'link', 'img', )

    def to_representation(self, instance):
        data = super().to_representation(instance)
        data['_id'] = instance.title.lower().replace(" ", "_")
        return data

api.py

class PortfolioList(ListAPIView):
    queryset = Portfolio.objects.all()
    serializer_class = PortfolioSerializer
    filter_backends = (DjangoFilterBackend,)
    filter_fields = ('title', '_id',)

Answer 1

您需要注释您的查询集，因为_id不是模型的一部分。只应在收到_id字段时在query_params中进行注释。

更好的解决方案是实现自定义过滤器后端。

    class PortfolioCustomFilterBackend(filters.BaseFilterBackend):

        def filter_queryset(self, request, queryset, view):
            _id = self.request.query_params.get('_id', None)
            if _id is not None:
                title = _id.replace('_', ' ')
                queryset = queryset.filter(title__iexact=title)
            return queryset