属性错误：'Serializer'对象在 django rest 框架中没有属性'Meta'

Question

我正在使用序列化程序。Serializer而不是ModelSerializer，后者不需要Meta类，但它一直说对象没有Meta属性。我不确定问题出在哪里，但当我运行localserver时，主页面出现错误，说api获取错误，而在终端中显示AttributeError:"Serializer"对象没有属性"Meta"。

我的观点：

class ClassView(viewsets.ModelViewSet):
queryset = Class.objects.all().order_by('-created_at')
serializer_class = ClassSerializer
serializer_action_classes = {
'get_all_students_of_a_class': ClassDetailSerializer,
}
# .annotate(total_students=Count('students_in_class'))
def get_serializer_class(self):
"""
returns a serializer class based on the action
that has been defined.
"""
try:
return self.serializer_action_classes[self.action]
except (KeyError, AttributeError):
return super(ClassView, self).get_serializer_class()

def get_all_students_of_a_class(self,request,pk=None):
"""
returns a class details with all the students signed up for the
class along with the subject.
"""
id = pk
if self.is_teacher(id):
online_classes = get_object_or_404(Class, id=id)
students = Student.objects.filter(online_class__id=id)
subject_details = Subject.objects.get(online_class__id=id)
total_students_in_class = online_classes.total_students_in_class
created_at = online_classes.created_at
updated_at = online_classes.updated_at
data = {
"teacher": self.get_teacher_instance(),
'total_students_in_class': total_students_in_class,
"students_in_class": students,
"subject": subject_details,
'created_at': created_at,
'last_updated_at': updated_at,
}
serializer_class = self.get_serializer_class()
serializer = serializer_class(data)
return Response(serializer.data, status=status.HTTP_200_OK)

我的序列化程序：

class ClassDetailSerializer(serializers.Serializer):
teacher = serializers.StringRelatedField()
subject = SubjectLevelSerializer()
total_students_in_class = serializers.ReadOnlyField()
students_in_class = serializers.StringRelatedField(many=True)
created_at = serializers.DateTimeField(read_only=True)
last_updated_at =  serializers.DateTimeField(read_only=True)       

我的网址：

path("class/<int:pk>/",teacher.ClassView.as_view({"get": "get_all_students_of_a_class","delete":"destroy"}),
),

然而，它是有效的，如果我从localhost/admin和其他api调用，我可以执行操作。

Answer 1

添加带有model = YourModel的Meta类

class ExampleDetailSerializer(serializers.Serializer):
employee = serializers.StringRelatedField()
person = PersonSerializer()
class Meta:
model = Example # model name
fields = ('__all__')

Answer 2

尝试使用"ViewSet"；而不是"；ModelViewSet"；。在使用ViewSet时，请确保自己定义列表、创建等功能。