Question

当向ListAPIView发出请求时，会多次调用get_queryset（）方法。它被调用了4次，直到我删除了默认的django模型权限，但现在它仍被调用两次。还有什么可能导致重复呼叫。

class PropertyPledgeList(generics.ListAPIView):

    serializer_class = PledgeListSerializer

    ordering_fields = ('amount_cents')

    def get_queryset(self):
        slug = self.kwargs['slug']
        return get_object_or_404(Property, slug=slug).pledges.all().prefetch_related("user")

Answer 1

重复查询是get_object_or_404()的结果。

如果要从URL关键字参数检索父对象，可以将其设置为调度方法中的属性，该方法仅被调用一次，然后在get_queryset()中访问已检索的对象。

from rest_framework.exceptions import NotFound

class PropertyPledgeList(generics.ListAPIView):
    queryset = PropertyPledge.objects.all()
    serializer_class = PledgeListSerializer

    def dispatch(self, request, *args, **kwargs):
        try:
            self.property = Property.objects.get(id=kwargs['slug'])
        except Property.DoesNotExist:
            self.property = None
        return super().dispatch(request, *args, **kwargs)

    def get_queryset(self):
        if not self.property:
            raise NotFound
        return self.property.get_pledges()

Django Rest Framework get_queryset不止一次被调用

1 个答案: