在 ViewSet 中按外键过滤，django-rest-framework

Question

我希望我的 api 根据从 url 路径检索到的外键从数据库中返回某些对象。如果我的网址看起来像api/get-club-players/1，我希望每个玩家对象都具有匹配的俱乐部 ID（在本例中为 club.id == 1）。我在下面粘贴我的代码：

models.py

class Club(models.Model):
    name = models.CharField(max_length=25)
    owner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.SET_NULL, null=True)

    def __str__(self):
        return self.name

class Player(models.Model):
    name = models.CharField(max_length=30)
    club = models.ForeignKey(Club, on_delete=models.SET_NULL, blank=True, null=True)

    
    def __str__(self):
        return self.name

serialziers.py

class ClubSerializer(serializers.ModelSerializer):
    class Meta:
        model = Club
        fields = 'id', 'owner', 'name'

class PlayerSerializer(serializers.ModelSerializer):
    class Meta:
        model = Player
        fields = 'id', 'name', 'offense', 'defence', 'club', 'position'

views.py，这是我最麻烦的部分：

class ClubViewSet(viewsets.ModelViewSet):
    queryset = Club.objects.all()
    serializer_class = ClubSerializer

class PlayerViewSet(viewsets.ModelViewSet):
    queryset = Player.objects.all()
    serializer_class = PlayerSerializer

class GetClubPlayersViewSet(viewsets.ViewSet):
    def list(self, request):
        queryset = Player.objects.all()
        serializer = PlayerSerializer(queryset, many=True)
        

    def retrieve(self,request, clubId):
        players = Player.objects.filter(club=clubId, many=True)
        if not players:
            return JsonResponse({'error': "No query found!"})
        else:
            serializer = PlayerSerializer(players)
            return Response(serializer.data)

urls.py

from rest_framework import routers
from django.urls import path, include
from .views import (GameViewSet, PlayerViewSet, ClubViewSet,
 GetClubPlayersViewSet, create_club, set_roster)

router = routers.DefaultRouter()
router.register(r'clubs', ClubViewSet, basename="clubs")
router.register(r'players', PlayerViewSet, basename="players")
router.register(r'get-club-players', GetClubPlayersViewSet, basename="club-players")

urlpatterns = [
    path('', include(router.urls)),
]

编辑： 现在 views.py 看起来像这样：

class GetClubPlayersViewSet(viewsets.ViewSet):
    queryset = Player.objects.all()

    def list(self, request):
        serializer = PlayerSerializer(self.queryset, many=True)
        return Response(serializer.data)

    def retrieve(self, request, *args, **kwargs):
        clubId = kwargs['get-club-players']
        players = Player.objects.filter(club=clubId, many=True)
        if not players:
            return JsonResponse({'error': "No query found!"})
        else:
            serializer = PlayerSerializer(players)
            return Response(serializer.data)

http://127.0.0.1:8000/api/get-club-players/ 返回所有玩家对象，但是当我在 url 中添加一个 clubId 时，我得到了这个错误：

编辑 2：

class GetClubPlayersViewSet(viewsets.ViewSet):
    queryset = Player.objects.all()
    
    def retrieve(self, request, *args, **kwargs):
        queryParams = self.request.GET.get('abc')
        if queryParams is None:
            queryset = Player.objects.none()
        else:
            queryset = Player.objects.filter(club = queryParams)
            serializer = PlayerSerializer(queryset)
        return Response(serializer.data)
    
    def list(self, request):
        serializer = PlayerSerializer(self.queryset, many=True)
        return Response(serializer.data)

Answer 1

您可以使用 kwargs 属性获取 url 参数。您需要为它修改您的检索方法的签名。

def retrieve(self, request, *args, **kwargs):
    clubId = kwargs['get-club-players']
    players = Player.objects.filter(club=clubId, many=True)
    ....

编辑

对于查询集错误，这是由于 DRF 需要 queryset 类属性或实现 get_queryset() 函数。在您的情况下，您可以像这样解决它：

class GetClubPlayersViewSet(viewsets.ViewSet):    
    queryset = Player.objects.all()

    def list(self, request):
        serializer = PlayerSerializer(self.queryset, many=True)

Answer 2

所以你可以定义你的查询集 -

def get_queryset(self):
    queryParams == self.request.GET.get('abc') # get queryparameter from url
    if queryParams is None:
        #queryset = anyModel.objects.all()
        queryset = anyModel.objects.none()
    else:
        queryset = anyModel.objects.filter(anyProperty = queryParams)
     return queryset

你的网址会像 -

api/get-club-players/?abc=1

这个 abc 可以是 id 或模型中的任何其他属性。

在您的检索方法中使用此 get_queryset 逻辑。

Answer 3

rest_framework.viewsets.ViewSet 有一个名为 lookup_field 的属性，您可以覆盖该属性。默认情况下lookup_field 的值为id。

在路由器中添加视图集时，lookup_field 作为参数名称添加到 url（例如 /api/get-club-players/:id/）。

您可以覆盖 GetClubPlayersViewSet 的 lookup_field 或通过更改访问正确的 kwargs 键 clubId = kwargs['get-club-players'] 到 clubId = kwargs['id']

或两者兼而有之：

class GetClubPlayersViewSet(viewsets.ViewSet):
    lookup_field = "clubId"
    queryset = Player.objects.all()

    # ....

    def retrieve(self, request, *args, **kwargs):
        clubId = kwargs[self.lookup_field]
        players = Player.objects.filter(club=clubId, many=True)
        if not players:
            return JsonResponse({'error': "No query found!"})
        else:
            serializer = PlayerSerializer(players)
            return Response(serializer.data)