如何在 Django 中指定 lookup_field

Question

我打算在 Django 中使用 UpdateAPIView。当我完成视图和运行服务器时，出现以下错误。

Expected view updateViewSet to be called with a URL keyword argument named "pk". Fix your URL conf, or set the `.lookup_field` attribute on the view correctly.

我想知道为什么我不应该在我的代码中将 lookup_field 指定为 pk 以及我可以使用什么来代替 pk。这是我的代码

serializers.py

from rest_framework import serializers
from .models import arduino

class arduinoSerializers (serializers.ModelSerializer) :
    name = serializers.CharField(source='name.username', read_only=True)
    class Meta :
        model = arduino
        fields = ['name', 'temp', 'humi']

views.py

from .models import arduino
from .serializers import arduinoSerializers
from rest_framework.viewsets import ViewSet
from rest_framework.response import Response
from rest_framework.generics import CreateAPIView, UpdateAPIView

class arduinoViewSet (ViewSet) :
    serializer_class = arduinoSerializers
    
    def data (self, request) :
        queryset = arduino.objects.filter(name=self.request.user)
        serializer = arduinoSerializers(queryset, many=True)
        return Response(serializer.data)
        
class createViewSet (CreateAPIView) :
    serializer_class = arduinoSerializers

    def perform_create (self, serializer) :
        serializer.save(name=self.request.user)

    def get_queryset (self) :
        user = self.request.user
        return arduino.objects.filter(name=user)

    def dataReceive (self, request) :
        queryset = self.get_queryset()
        serializer = arduinoSerializers(queryset, many=True)
        if serializer.is_valid() :
            perform_create(serializer)
        return Response(serializer.data)

class updateViewSet (UpdateAPIView) :
    serializer_class = arduinoSerializers
    lookup_field = 'pk'

    def perform_update (self, serializer) :
        serializer.update(name=self.request.user)

    def get_queryset (self) :
        user = self.request.user
        return arduino.objects.filter(name=user)

    def dataReceive (self, request) :
        queryset = self.get_queryset()
        serializer = arduinoSerializers(queryset, many=True)
        if serializer.is_valid() :
            perform_update(serializer)
            return Response(serializer.data)

urls.py

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', include('api.urls')),
    path('auth/', include('rest_auth.urls')),
    path('auth/registration/', include('rest_auth.registration.urls')),
]

api\urls.py

urlpatterns = [
    path('data/', arduinoViewSet.as_view({'get' : 'data'})),
    path('create/', createViewSet.as_view()),
    path('update/', updateViewSet.as_view()),
]

提前致谢

Answer 1

据说需要用主键调用URL，所以应该是

urlpatterns = [
    path('data/<int:pk>/', arduinoViewSet.as_view({'get' : 'data'})),
]

但老实说，我认为 pk 可以是任何值，只要它是唯一的，但是你的错误首先发生是因为，因为你没有指定字段，Django 会寻找一个名为 'pk'.

Answer 2

更新视图不知道要更新哪个 id(pk)。尝试在更新中添加 pk url

urlpatterns = [
    path('update/<int:pk>/', updateViewSet.as_view()),
]

Answer 3

虽然接受的答案解决了您遇到的问题，但由于您的问题的标题更普遍地与指定 UpdateView 的查找字段有关，我想继续 post 对于可能遇到此问题的任何人，如果他们试图根据 pk.

以外的其他内容进行查找，这是一个更通用的答案

查看 CCBV docs for UpdateView.get_object(), you can see that if <int:pk> is not in the url, then UpdateView looks for slug_field (with a default name of slug which you can see under Attributes on the above page). Therefore, instead of <int:pk> in the url, you could put <slug:slug> in the url. In this case the second slug in the <slug:slug> part of the declaration is the default url keyword used by UpdateView if looking up by a slug. As an aside, if you name your slug keyword argument in your url declaration something like: <slug:different_slug_name>, then you would need to specify slug_url_kwarg = different_slug_name on the UpdateView. Finally, if the SlugField 在您的模型上 被命名为 slug 以外的名称（同样，您可以在 CCBV 的属性中看到默认值） , 然后在 UpdateView 上你需要指定 slug_field = model_slug_field_name.

如何在 Django 中指定 lookup_field

How to specify lookup_field in django

django

django-views

django-generic-views

django-rest-framework