如何从ModelViewSet中的另一个对象的PK访问对象

Question

模型的通用结构是有教师和设备，每个设备与教师ID / PK具有ForeignKey关系。

我正在尝试以这样的方式创建我的API：当转到教师的详细信息视图时，将显示所有关联的设备。我已经重写了get_serializer_class（）来指定在适当的时候使用哪个序列化程序，但是无法弄清楚如何根据细节视图正确地更改Queryset。错误发布在下方。

Got AttributeError when attempting to get a value for field `brand` on serializer `DeviceSerializer`.
The serializer field might be named incorrectly and not match any attribute or key on the `Teacher` instance.
Original exception text was: 'Teacher' object has no attribute 'brand'.

class TeacherViewSet(viewsets.ModelViewSet):
    queryset = Teacher.objects.order_by('campus','name')
    serializer_class = TeacherSerializer
    detail_serializer_class = DeviceSerializer

    def get_serializer_class(self):
        if self.action == 'retrieve':
            if hasattr(self, 'detail_serializer_class'):
                return self.detail_serializer_class
        return super(TeacherViewSet, self).get_serializer_class()

    def get_queryset(self, pk=None):
        if pk is not None:
            return Device.objects.filter(device__owner=self.kwargs.get('pk')
        return Teacher.objects.all()

Answer 1

通过在我的TeacherSerializer中添加嵌套的DeviceSerializer来解析设备对象列表，我能够获得所需的输出。

class TeacherSerializer(serializers.ModelSerializer):
devices = DeviceSerializer(many=True)

class Meta:
    model = Teacher
    fields = ('id', 'name', 'campus', 'email', 'devices')

Answer 2

我假设您正在使用DRF。如果是这种情况，只需将TeacherSerializer调整为：

def TeachSearializer(serializer.ModelSerializer):
    devices = serializers.SerializerMethodField()

    class Meta:
        model = Teacher
        fields = '__all__'

    def get_devices(self, obj):
        return Devices.objects.filter(teacher=obj)

就是这样，每次在教师对象上使用序列化程序时，他们的设备都会添加到字段devices上