Django Rest Framework（多对多字段上的 GET 过滤器）答案

【问题标题】：Django Rest Framework (GET filter on ManyToMany field)Django Rest Framework（多对多字段上的 GET 过滤器）
【发布时间】：2014-11-14 14:38:00
【问题描述】：

我试图弄清楚如何按值过滤 ManyToMany 字段。在 Django 中，它就像 queryset.filter(m2mfield__name) 一样简单，但我无法弄清楚我缺少什么。我正在使用Django Rest Framework 和DjangoFilterBackend。

型号：

class City(models.Model):
    name = models.CharField(max_length=80)

class State(models.Model):
    name = models.CharField(max_length=50)
    cities = models.ManyToManyField(City)

过滤器：

import django_filters

class StateFilter(django_filters.FilterSet):
    cities = django_filters.CharFilter(
        name='cities__name',
        lookup_type='contains',
    )

    class Meta:
        model = State
        fields = ('name', 'cities')

序列化器：

class CitySerializer(serializers.ModelSerializer):
    class Meta:
        model = City
        fields = ('name', )

class StateSerializer(serializers.ModelSerializer):
    cities = CitySerializer(many=True)

    class Meta:
        model = State
        fields = ('name', 'cities')
        filter_class = StateFilter

查看：

from rest_framework.generics import ListAPIView, RetrieveAPIView
from .serializers import StateSerializer

class StateList(ListAPIView):
    queryset = State.objects.all()
    serializer_class = StateSerializer
    filter_fields = ('name', 'cities')

../api/states/ 的输出当前是：

 [
     "name": "Florida",
     "cities": [
          "name": "Tampa",
          "name": "St. Petersburg",
          "name": "Orlando"
     ],
     "name": "North Carolina",
     "cities": [
          "name": "Raleigh",
          "name": "Charlotte",
          "name": "Greensboro"
     ]
 ]

如何通过 GET 调用按名称过滤城市，例如：

../api/states/?cities=Charlotte

上面的结果应该是：

 [
     "name": "North Carolina",
     "cities": [
          "name": "Raleigh",
          "name": "Charlotte",
          "name": "Greensboro"
     ]
 ]

【问题讨论】：

你能展示你的 ViewSet 吗？
@Zulu，我已按要求添加了 ViewSet。
REST_FRAMEWORK = { 'FILTER_BACKEND': 'rest_framework.filters.DjangoFilterBackend', }

标签： django django-rest-framework django-filter

【解决方案1】：

好吧，我发现我做错了什么。它在视图中。我没有在视图上声明 filter_class：

from rest_framework.generics import ListAPIView, RetrieveAPIView
from .serializers import StateSerializer
from .filters import StateFilter

class StateList(ListAPIView):
    queryset = State.objects.all()
    serializer_class = StateSerializer
    filter_fields = ('name', 'cities')
    filter_class = StateFilter  # This was missing

我不小心把它放在了序列化器上。

【讨论】：