Django Rest框架（对ManyToMany字段的GET过滤器） [英] Django Rest Framework (GET filter on ManyToMany field)

问题描述

我试图找出如何通过值来过滤ManyToMany字段。在Django中，它和queryset.filter（m2mfield__name）一样简单，但是我不清楚我失踪了什么。我正在使用 Django Rest Framework 和 DjangoFilterBackend 。

模型： / strong>

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

从rest_framework.generics导入ListAPIView，RetrieveAPIView 
从.serializers import StateSerializer 
 
 class StateList（ListAPIView）：
 queryset = State.objects.all（）
 serializer_class = StateSerializer 
 filter_fields =（'name'，'cities'）
  

../api/states/的输出目前为：

  [
name：Florida，
cities：[
name：Tampa，
name圣彼得堡，
名称：奥兰多
]，
名称：北卡罗来纳州，
cities：[
name Raleigh，
name：Charlotte，
name：Greensboro
] 
] 
  pre> 
 
 
如何通过GET调用过滤城市，例如：
 
 
 ../ api / states /？cities = Charlotte 
 
 
上面的结果应该是：
  [
name：North Carolina，
cities：[
name Raleigh，
name：Charlotte，
name：Greensboro
] 
] 
  pre> 
 
解决方案
嗯，我发现我做错了什么，在这个视图中，我没有在查看：
  from .serializers import StateSeria lizer 
 from .filters import StateFilter 
 
 class StateList（ListAPIView）：
 queryset = State.objects.all（）
 serializer_class = StateSerializer 
 filter_fields = （'name'，'cities'）
 filter_class = StateFilter＃这是缺少
  
我不小心把它放在串行器上。
 
I am trying to figure out how to filter a ManyToMany field by value. In Django, it is as simple as queryset.filter(m2mfield__name), but I can't quite figure out what I am missing. I am using the Django Rest Framework, and the DjangoFilterBackend.

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

class State(models.Model):
    name = models.CharField(max_length=50)
    cities = models.ManyToManyField(City)
Filters:
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')
Serializers:
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
View:
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')
The output for ../api/states/ is currently:
 [
     "name": "Florida",
     "cities": [
          "name": "Tampa",
          "name": "St. Petersburg",
          "name": "Orlando"
     ],
     "name": "North Carolina",
     "cities": [
          "name": "Raleigh",
          "name": "Charlotte",
          "name": "Greensboro"
     ]
 ]
How can I filter the cities via a GET call by name such as:

  
../api/states/?cities=Charlotte
The result of the above should be:
 [
     "name": "North Carolina",
     "cities": [
          "name": "Raleigh",
          "name": "Charlotte",
          "name": "Greensboro"
     ]
 ]

解决方案
Well, I found out what I was doing wrong. It was in the view. I had not declared filter_class on the view:
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
I accidentally placed it on the serializer instead.

                        
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