Question

我尝试使用诸如this之类的示例使用Django Rest Framework插入和更新可写的嵌套序列化程序。但这是行不通的，因为在执行 serializer.is_valid() 之后，它以某种方式丢失了 serializer.validated_data 的引用，就像从未发送过一样。

我该怎么做？

我的模特

class User(AbstractUser):

    institution = models.ForeignKey(Institution, on_delete=None, null=True, blank=True)

    class Meta:
        db_table = 'User'
        managed = True
        verbose_name = 'Users'
        verbose_name_plural = 'Users'
        ordering = ['id']

    def __str__(self):
        return self.email

class Institution(models.Model):
    id = models.AutoField(db_column='id', primary_key=True)
    name = models.CharField(db_column='name', max_length=255, null=False)
    country = models.CharField(db_column='country', max_length=255, null=False)

    class Meta:
        db_table = 'Institution'
        managed = True
        verbose_name = 'Institutions'
        verbose_name_plural = 'Institutions'
        ordering = ['id']

    def __str__(self):
        return self.name

我的序列化器

class InstitutionSerializer(serializers.ModelSerializer):

    class Meta:
        model = Institution
        fields = '__all__'
        datatables_always_serialize = ('id', 'name', 'country')

class UserSerializer(serializers.HyperlinkedModelSerializer):
    institution = InstitutionSerializer()

    def create(self, validated_data):
        return User.objects.create_user(**validated_data)

    def update(self, instance, validated_data):
        institution_data = validated_data['institution']
        instance.institution = Institution.objects.get(pk=institution_data['id'])
        return instance

    class Meta:
        model = User
        fields = (
            'id',
            'username',
            'first_name',
            'last_name',
            'email',
            'password',
            'is_active',
            'institution',
        )
        datatables_always_serialize = (
            'id',
            'username',
            'first_name',
            'last_name',
            'email',
            'is_active',
            'institution',
        )

我的观点

class UserViewSet(ModelViewSet):
    serializer_class = UserSerializer
    permission_classes = (IsSuperUserPermission,)

    def list(self, request, **kwargs):
        params = Q()
        if 'search[value]' in request.GET and request.GET['search[value]'] != '':
            params = Q(username__icontains=request.GET['search[value]']) |\
                     Q(first_name__icontains=request.GET['search[value]']) |\
                     Q(last_name__icontains=request.GET['search[value]']) |\
                     Q(email__icontains=request.GET['search[value]']) |\
                     Q(institution__name__icontains=request.GET['search[value]'])

        queryset = User.objects.filter(params).select_related().order_by('id')
        serializer = self.serializer_class(queryset, many=True)
        return Response(serializer.data)

    def retrieve(self, request, *args, **kwargs):
        queryset = User.objects.filter(pk=request.GET['pk']).select_related()
        serializer = UserSerializer(queryset, many=True)
        return Response(serializer.data)

    def get_permissions(self):
        if self.action in ('create',):
            self.permission_classes = [AllowAny, ]
        return super(self.__class__, self).get_permissions()

    def create(self, request, *args, **kwargs):
        serializer = UserSerializer(data=request.data)
        if serializer.is_valid():
            serializer.create(serializer.validated_data)
            return Response(serializer.data)
        else:
            return Response(serializer.errors, status.HTTP_500_INTERNAL_SERVER_ERROR)

    def partial_update(self, request, *args, **kwargs):
        user = User.objects.get(pk=request.data['id'])
        serializer = UserSerializer(instance=user, data=request.data, partial=True)
        if serializer.is_valid():

            if 'password' in serializer.validated_data:
                serializer.validated_data['password'] = make_password(serializer.validated_data['password'])

            serializer.update(user, serializer.validated_data)
            return Response(serializer.data)
        else:
            return Response(serializer.errors, status.HTTP_500_INTERNAL_SERVER_ERROR)

编辑。

我提交这样的数据：

{
    "username": "BLA",
    "email": "BLA@BLA.com",
    "first_name": "BLA",
    "last_name": "BLA",
    "institution": 1,
    "is_active": true,
    "password": "bla12345"
}

Answer 1

为什么会出现这个问题？

在更新有效负载中，您以整数形式提供 institution 数据，该数据表示 PK 。但是，您还已经在 InstitutionSerializer() 类中定义了嵌套的序列化器 UserSerializer() 。因此，DRF希望使用 dict 这样的对象（通过提及，DRF可能会引发一些错误。我不确定为什么在这种情况下不会发生这种错误）。

解决方案是什么？

由于您要传递机构ID ，因此我认为，仅在HTTP GET个请求上需要嵌套输出。因此，请覆盖 __init__() 类的 UserSerializer() 方法，并将嵌套序列化程序的使用限制为仅 HTTP GET 请求

这是代码

class UserSerializer(serializers.HyperlinkedModelSerializer): def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) if self.context['request'].method == 'GET': self.fields['institution'] = InstitutionSerializer() institution = InstitutionSerializer() # remove this def create(self, validated_data): return User.objects.create_user(**validated_data) def update(self, instance, validated_data): institution_data = validated_data['institution'] instance.institution = Institution.objects.get(pk=institution_data['id']) return instance class Meta: model = User fields = ( 'id', 'username', 'first_name', 'last_name', 'email', 'password', 'is_active', 'institution', ) datatables_always_serialize = ( 'id', 'username', 'first_name', 'last_name', 'email', 'is_active', 'institution', )

UPDATE-1

如下更改 partial_update() 类的 UserViewSet 方法，

def partial_update(self, request, *args, **kwargs): user = User.objects.get(pk=request.data['id']) serializer = UserSerializer(instance=user, data=request.data, partial=True, context={"request": request}) # change is here <<< if serializer.is_valid(): if 'password' in serializer.validated_data: serializer.validated_data['password'] = make_password(serializer.validated_data['password']) serializer.update(user, serializer.validated_data) return Response(serializer.data) else: return Response(serializer.errors, status.HTTP_500_INTERNAL_SERVER_ERROR)

Answer 2

我找到了一种使用JPG想法解决问题的方法。我只是使用PrimaryKeyRelatedField添加一个else，以允许序列化程序从id中获取模型的引用。可能还有另一种解决方案，但这个解决方案比多个序列化程序看起来更好。

class UserSerializer(serializers.HyperlinkedModelSerializer):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if self.context['request'].method == 'GET':
            self.fields['institution'] = InstitutionSerializer()
        else:
            self.fields['institution'] = serializers.PrimaryKeyRelatedField(queryset=Institution.objects.all())

Django Rest Framework插入和更新可写的嵌套序列化程序

2 个答案:

为什么会出现这个问题？

解决方案是什么？

UPDATE-1