django - 尝试访问 ViewSet 创建定义中的 request.data 时出现 KeyError 'id'

Question

我最近从 drf 2.4 升级到 v3，并一直在尝试覆盖我的其中一个 ViewSet 中的 def Create。但是，当尝试访问我保存到序列化器变量的 request.data 时，我会收到错误:KeyError at/api/appointments/ 'id'

我包含了我的 ViewSet 代码、序列化程序和以下错误的回溯:

class AppointmentViewSet(viewsets.ModelViewSet):
    queryset = Appointment.objects.all()
    serializer_class = AppointmentSerializer
    permission_classes = (permissions.IsAuthenticatedOrReadOnly,
                      IsOwnerOrReadOnly,)
    def create(self, request):
            serializer = AppointmentSerializer(data=request.data)
            if serializer.is_valid(raise_exception=True):
            #get the datetime object from the request data and filter availability objects, datetime stored in attribute .when
                    avQueryset = Availability.objects.filter(date__range=(serializer.data.when, serializer.data.when))
    def pre_save(self, obj):
            obj.service_recipient = self.request.user

序列化器

class AppointmentSerializer(serializers.ModelSerializer):
        class Meta:
                model = Appointment
                fields = ('id','availability' , 'business_location', 'services', 'when', 'service_recipient', 'completed')

repr(序列化器)

AppointmentSerializer():
    id = IntegerField(label='ID', read_only=True)
    availability = PrimaryKeyRelatedField(queryset=Availability.objects.all())
    business_location = PrimaryKeyRelatedField(queryset=BusinessLocation.objects.all())
    services = PrimaryKeyRelatedField(many=True, queryset=Service.objects.all())
    when = DateTimeField(allow_null=True, required=False)
    service_recipient = PrimaryKeyRelatedField(queryset=User.objects.all())
    completed = BooleanField(help_text='Set to true when appointment has been completed.', required=False)

回溯

Environment:


Request Method: POST
Request URL: http://104.131.110.138/api/appointments/

Django Version: 1.7.1
Python Version: 2.7.6
Installed Applications:
('django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'webapp',
 'rest_framework')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


Traceback:
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
  111.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/usr/local/lib/python2.7/dist-packages/django/views/decorators/csrf.py" in wrapped_view
  57.         return view_func(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/viewsets.py" in view
  85.             return self.dispatch(request, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/views.py" in dispatch
  407.             response = self.handle_exception(exc)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/views.py" in dispatch
  404.             response = handler(request, *args, **kwargs)
File "/home/appointments/appointments/webapp/views.py" in create
  57.                   avQueryset = Availability.objects.filter(date__range=(serializer.data.when, serializer.data.when))
File "/usr/local/lib/python2.7/dist-packages/rest_framework/serializers.py" in data
  422.         ret = super(Serializer, self).data
File "/usr/local/lib/python2.7/dist-packages/rest_framework/serializers.py" in data
  179.                 self._data = self.to_representation(self.validated_data)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/serializers.py" in to_representation
  387.             attribute = field.get_attribute(instance)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/fields.py" in get_attribute
  277.         return get_attribute(instance, self.source_attrs)
File "/usr/local/lib/python2.7/dist-packages/rest_framework/fields.py" in get_attribute
  65.                 instance = instance[attr]

Exception Type: KeyError at /api/appointments/
Exception Value: 'id'

Answer 1

当您似乎打算使用 serializer.validated_data 时，您正在使用 serializer.data。当您希望序列化现有对象时，您实际上应该只使用 serializer.data，这需要在初始化它时将 实例 传递到序列化器中。

问题是您没有将实例传递到序列化器中，因此它期望传递到其中的初始数据可以被序列化。这需要 data 具有序列化器上的所有字段，包括似乎不存在的 id。

您可以使用serializer.validated_data["when"]获取经过验证的数据，而不是序列化数据。 Django REST Framework 的文档 deserializing objects 下特别提到了这一点。 .