Django-REST：通过用户名而不是主键获取用户

Question

I am using the basic UserViewSet derived from ModelViewSet.
Retrieving a user with a primary-key via api/users/<pk> works fine.
But I also want to be able to retrieve a User by Username.

I have added a new detail route but I always get 404 on my server when I try to get the user with the url /api/users/retrieve_by_username/altoyr .

class UserViewSet(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer

    @detail_route(methods=['get'])
    def retrieve_by_username(self, request, username=None):
        try:
            user = User.objects.get(userName=username)
            return Response(user)
        except User.DoesNotExist:
            return Response("No user with username found!", status=status.HTTP_400_BAD_REQUEST)

The Urls are registered via a router:

router = DefaultRouter()
router.register(r'users', views.UserViewSet)

# The API URLs are now determined automatically by the router.
# Additionally, we include the login URLs for the browsable API.
urlpatterns = [
    url(r'^', include(router.urls)),
    url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
]

I think I am missing an important part of building rest urls.

Answer 1

You can do this by adding a list route like:

@list_route(methods=['get'], url_path='retrieve_by_username/(?P<username>\w+)')
def getByUsername(self, request, username ):
    user = get_object_or_404(User, username=username)
    return Response(UserSerializer(user).data, status=status.HTTP_200_OK)

and the url will be like:

/api/users/retrieve_by_username/altoyr

Answer 2

You can override the retrieve() ViewSet action. You'll find more detail here: https://www.django-rest-framework.org/api-guide/viewsets/

from django.shortcuts import get_object_or_404
from rest_framework.response import Response

class UserViewSet(viewsets.ModelViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer

    def retrieve(self, request, pk=None):
        queryset = User.objects.filter(username=pk)
        contact = get_object_or_404(queryset, pk=1)
        serializer = ContactSerializer(contact)
        return Response(serializer.data)

Answer 3

The answer from Anush Devendra is right but need a little update due to deprecations on v3.9 .

action decorator replaces list_route and detail_route Both list_route and detail_route are now deprecated in favour of the single action decorator. They will be removed entirely in 3.10. The action decorator takes a boolean detail argument.

• Replace detail_route uses with @action(detail=True).
• Replace list_route uses with @action(detail=False).

...
from rest_framework.decorators import action
from rest_framework.response import Response
from django.shortcuts import get_object_or_404
from rest_framework import status

class UserViewSet(viewsets.ModelViewSet):
    ...

    @action(methods=['get'], detail=False,
            url_path='username/(?P<username>\w+)')
    def getByUsername(self, request, username):
        user = get_object_or_404(User, username=username)
        data = UserSerializer(user, context={'request': request}).data
        return Response(data, status=status.HTTP_200_OK)

I add context={'request': request} because I have url as HyperlinkedIdentityField in my serializer. If you don't have it, you probably don't need it.