Question

我在DRF中有一个序列化程序类，如下所示：

class ProjectSerializer(serializers.HyperlinkedModelSerializer):
    created_by = UserSerializer() # created_by is an FK to User model

    class Meta:
        model = Project
        fields = ('id', 'title', 'created_by')

我的观点：

class ProjectList(generics.ListCreateAPIView):
    model = Project
    serializer_class = ProjectSerializer
    filter_fields = ('title',)

    def post(self, request, format=None):
        serializer = ProjectSerializer(data={
            "id": 12, 
            "title": "FooBar's Project", 
            "created_by": {
                "id": 1, 
                "username": "foobar", 
                "first_name": "foo", 
                "last_name": "bar",
            },
        })

    if serializer.is_valid():
        serializer.save()
    else:
        print serializer.errors
    return Response(serializer.data, status=status.HTTP_201_CREATED)

除了DRF抱怨：

之外，这几乎与预期一样

{'created_by': [{'username': [u'User with this Username already exists.']}]}

我想要的是项目是参考现有用户创建的。我在这里做错了什么？

注意：我正在追踪DRF的干线，而不是来自奶酪店。

Answer 1

如果要分配现有用户而不是创建一个用户，则嵌套序列化程序不是这样。由于您只想将关系添加到用户，您需要查看关系。

PrimaryKeyRelatedField是可行的方法，因为此字段可写，您还需要传递queryset属性。

created_by = serializers.PrimaryKeyRelatedField(queryset=User.objects.all())

请参阅文档以检查可传递给此字段的其他选项：

http://django-rest-framework.org/api-guide/relations#primarykeyrelatedfield

然后您的示例帖子可能如下所示：

def post(self, request, format=None):
    user = User.objects.get(pk=8)
    serializer = ProjectSerializer(data={
        "id": 12, 
        "title": "FooBar's Project", 
        "created_by": user.pk,
    })

Answer 2

（代表问题作者发布）。

这是可行的解决方案：

# serializers.py    

class ProjectSerializer(serializers.HyperlinkedModelSerializer):
    ...
    created_by = serializers.PrimaryKeyRelatedField(
        queryset=User.objects.all()
    )

    class Meta:
        model = Project
        fields = ('id', 'title', 'created_by')

# views.py

class ProjectList(generics.ListCreateAPIView):
    model = Project
    serializer_class = ProjectSerializer
    filter_fields = ('title',)

    def post(self, request, format=None):
        serializer = ProjectSerializer(data={
            "title": request.DATA.get('title'),
            "created_by": request.user.pk,
        })
        if serializer.is_valid():
            serializer.save()
        else:
           return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
        return Response(serializer.data, status=status.HTTP_201_CREATED)

Django Rest Framework - 无法使用现有的FK引用创建对象

2 个答案: