Question

我编写了自定义FilterSet来按两个字段过滤查询集，但是当它同时对两个字段进行过滤时，它不能正常工作。

我的FilterSet：

class EventFilter(filters.FilterSet):
    values = None
    default = None

    category = filters.ModelMultipleChoiceFilter(
        queryset=EventCategory.objects.all(),
    )
    interval = filters.CharFilter(
        method='filter_interval'
    )

    class Meta:
        model = Event
        fields = ('category', 'interval')

    def filter_interval(self, queryset, name, value):
        if self.request.query_params.get('current_time'):
            try:
                interval = getattr(self, f'get_{value}_interval')()
                interval = list(map(lambda date: self.to_utc(date), interval))
                return self.queryset.filter(Q(status=Event.STARTED) | (Q(status=Event.NOT_STARTED, start_at__range=interval)))
            except Exception as e:
                pass
        return queryset

APIView：

class ListEventsAPIView(generics.ListAPIView):
    serializer_class = ListEventsSerializer
    filter_class = EventFilter
    search_fields = 'title',
    filter_backends = filters.SearchFilter, DjangoFilterBackend

    def get_queryset(self):
        return Event.objects.filter(Q(status=Event.STARTED) | (Q(status=Event.NOT_STARTED) & Q(start_at__gte=date)))

当我尝试仅按类别进行过滤时，会在此处生成SQL：

SELECT "*" FROM "events" WHERE (("events"."status" = 'started'
OR ("events"."status" = 'not_started' 
AND "events"."start_at" >= '2019-06-19T13:24:26.444183+00:00'::timestamptz)) 
AND "events"."category_id" = 'JNPIZF54n5q')

当我同时过滤两种情况时：

SELECT "*" FROM "events" WHERE (("events"."status" = 'started' 
OR ("events"."status" = 'not_started' AND "events"."start_at" >= '2019-06-19T13:24:26.444183+00:00'::timestamptz)) 
AND ("events"."status" = 'started' OR ("events"."start_at" BETWEEN '2019-06-19T07:16:48.549000+00:00'::timestamptz AND '2019-06-30T20:59:59.000059+00:00'::timestamptz AND "events"."status" = 'not_started')))

Answer 1

您的问题在这一行：

               return self.queryset.filter(Q(status=Event.STARTED) | (Q(status=Event.NOT_STARTED, start_at__range=interval)))

您正在使用FilterSet类本身的queryset。该查询集没有应用任何以前的过滤器，因此使用它可以取消另一个过滤器。只需从此行中删除self.即可使用传递给该函数的queryset作为参数，一切都会正常进行。

自定义FilterSet不会同时按两个字段进行过滤

1 个答案: