如何使用Django Rest框架更新OneToOneField

我正在尝试从移动客户端通过RESTAPI上传图像。我已经设法使用对REST端点的多部分请求来实现它，但是当我尝试更新映像时，由于OneToOneField上的约束，请求没有得到正确处理

---

以下是我实现API的方式：

型号.py

class Hotel(models.Model):
    name = models.CharField(max_length=500, null=False, blank=False)
    address = models.CharField(max_length=500, null=False, blank=False)
    rating = models.FloatField()
    owner = models.CharField(max_length=200, null=False)

    class Meta:
        ordering = ['name']


class HotelPhoto(models.Model):
    photo = models.ImageField(upload_to='hotel_photos', null=True)
    hotel = models.OneToOneField(Hotel, on_delete=models.CASCADE, primary_key=True)

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        photo_serializer = HotelPhotoSerializer(data=request.data,
                                                context={'request': request})

        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

class HotelSerializer(serializers.HyperlinkedModelSerializer):
    photo = serializers.ImageField(source='hotelphoto.photo', read_only=True)

    class Meta:
        model = Hotel
        fields = ['url', 'id', 'name', 'address', 'rating', 'owner', 'photo']


class HotelPhotoSerializer(serializers.ModelSerializer):
    photo_url = serializers.SerializerMethodField()

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo', 'photo_url']

    def get_photo_url(self, obj):
        return self.context['request'].build_absolute_uri(obj.photo.url)

# Didn't change the HotelSerializer

class HotelPhotoSerializer(serializers.ModelSerializer):
    hotel = serializers.PrimaryKeyRelatedField(
            many=False,
            queryset=Hotel.objects.all())

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo']

    def create(self, validated_data):
        # Instead of creating a new HotelPhoto instance
        # changed the photo field from the Hotel instance
        hotel = validated_data.get('hotel')
        photo = validated_data.get('photo')
        hotel.hotelphoto.photo.save(photo.name, photo)
        hotel.save()
        return hotel.hotelphoto

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        # I'm already sending the hotel id on the POST request
        photo_serializer = HotelPhotoSerializer(data=request.data)
        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

视图.py

class Hotel(models.Model):
    name = models.CharField(max_length=500, null=False, blank=False)
    address = models.CharField(max_length=500, null=False, blank=False)
    rating = models.FloatField()
    owner = models.CharField(max_length=200, null=False)

    class Meta:
        ordering = ['name']


class HotelPhoto(models.Model):
    photo = models.ImageField(upload_to='hotel_photos', null=True)
    hotel = models.OneToOneField(Hotel, on_delete=models.CASCADE, primary_key=True)

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        photo_serializer = HotelPhotoSerializer(data=request.data,
                                                context={'request': request})

        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

class HotelSerializer(serializers.HyperlinkedModelSerializer):
    photo = serializers.ImageField(source='hotelphoto.photo', read_only=True)

    class Meta:
        model = Hotel
        fields = ['url', 'id', 'name', 'address', 'rating', 'owner', 'photo']


class HotelPhotoSerializer(serializers.ModelSerializer):
    photo_url = serializers.SerializerMethodField()

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo', 'photo_url']

    def get_photo_url(self, obj):
        return self.context['request'].build_absolute_uri(obj.photo.url)

# Didn't change the HotelSerializer

class HotelPhotoSerializer(serializers.ModelSerializer):
    hotel = serializers.PrimaryKeyRelatedField(
            many=False,
            queryset=Hotel.objects.all())

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo']

    def create(self, validated_data):
        # Instead of creating a new HotelPhoto instance
        # changed the photo field from the Hotel instance
        hotel = validated_data.get('hotel')
        photo = validated_data.get('photo')
        hotel.hotelphoto.photo.save(photo.name, photo)
        hotel.save()
        return hotel.hotelphoto

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        # I'm already sending the hotel id on the POST request
        photo_serializer = HotelPhotoSerializer(data=request.data)
        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

序列化程序.py

class Hotel(models.Model):
    name = models.CharField(max_length=500, null=False, blank=False)
    address = models.CharField(max_length=500, null=False, blank=False)
    rating = models.FloatField()
    owner = models.CharField(max_length=200, null=False)

    class Meta:
        ordering = ['name']


class HotelPhoto(models.Model):
    photo = models.ImageField(upload_to='hotel_photos', null=True)
    hotel = models.OneToOneField(Hotel, on_delete=models.CASCADE, primary_key=True)

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        photo_serializer = HotelPhotoSerializer(data=request.data,
                                                context={'request': request})

        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

class HotelSerializer(serializers.HyperlinkedModelSerializer):
    photo = serializers.ImageField(source='hotelphoto.photo', read_only=True)

    class Meta:
        model = Hotel
        fields = ['url', 'id', 'name', 'address', 'rating', 'owner', 'photo']


class HotelPhotoSerializer(serializers.ModelSerializer):
    photo_url = serializers.SerializerMethodField()

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo', 'photo_url']

    def get_photo_url(self, obj):
        return self.context['request'].build_absolute_uri(obj.photo.url)

# Didn't change the HotelSerializer

class HotelPhotoSerializer(serializers.ModelSerializer):
    hotel = serializers.PrimaryKeyRelatedField(
            many=False,
            queryset=Hotel.objects.all())

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo']

    def create(self, validated_data):
        # Instead of creating a new HotelPhoto instance
        # changed the photo field from the Hotel instance
        hotel = validated_data.get('hotel')
        photo = validated_data.get('photo')
        hotel.hotelphoto.photo.save(photo.name, photo)
        hotel.save()
        return hotel.hotelphoto

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        # I'm already sending the hotel id on the POST request
        photo_serializer = HotelPhotoSerializer(data=request.data)
        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

---

这就是我得到的错误：

Error uploading image: {'hotel': [ErrorDetail(string='hotel photo with this hotel already exists.', code='unique')]}
Bad Request: /hotels/photo/upload/

我知道这是由于OneToOneField上的限制，因为我已经上传了一张照片，但是我应该如何做才能更新

HotelPhoto.photo

字段

我尝试过的

• 在序列化程序上使用

  partial=True

  在

  HotelPhotoUpload

  视图上实现put方法，但给出了相同的错误
• 我考虑在序列化程序上覆盖

  validate

  方法，但我不知道是否需要在照片本身上验证任何内容。我希望这个框架能帮我解决这个问题
• 考虑合并

  HotelPhoto

  和

  Hotel

  模型，但这需要对其他代码进行大的重构

---

编辑：

我目前正在使用Django3.0.2。 根据neferpitou的回答，我在做了这些小改动后，成功地使其工作：

序列化程序.py

class Hotel(models.Model):
    name = models.CharField(max_length=500, null=False, blank=False)
    address = models.CharField(max_length=500, null=False, blank=False)
    rating = models.FloatField()
    owner = models.CharField(max_length=200, null=False)

    class Meta:
        ordering = ['name']


class HotelPhoto(models.Model):
    photo = models.ImageField(upload_to='hotel_photos', null=True)
    hotel = models.OneToOneField(Hotel, on_delete=models.CASCADE, primary_key=True)

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        photo_serializer = HotelPhotoSerializer(data=request.data,
                                                context={'request': request})

        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

class HotelSerializer(serializers.HyperlinkedModelSerializer):
    photo = serializers.ImageField(source='hotelphoto.photo', read_only=True)

    class Meta:
        model = Hotel
        fields = ['url', 'id', 'name', 'address', 'rating', 'owner', 'photo']


class HotelPhotoSerializer(serializers.ModelSerializer):
    photo_url = serializers.SerializerMethodField()

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo', 'photo_url']

    def get_photo_url(self, obj):
        return self.context['request'].build_absolute_uri(obj.photo.url)

# Didn't change the HotelSerializer

class HotelPhotoSerializer(serializers.ModelSerializer):
    hotel = serializers.PrimaryKeyRelatedField(
            many=False,
            queryset=Hotel.objects.all())

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo']

    def create(self, validated_data):
        # Instead of creating a new HotelPhoto instance
        # changed the photo field from the Hotel instance
        hotel = validated_data.get('hotel')
        photo = validated_data.get('photo')
        hotel.hotelphoto.photo.save(photo.name, photo)
        hotel.save()
        return hotel.hotelphoto

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        # I'm already sending the hotel id on the POST request
        photo_serializer = HotelPhotoSerializer(data=request.data)
        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

视图.py

class Hotel(models.Model):
    name = models.CharField(max_length=500, null=False, blank=False)
    address = models.CharField(max_length=500, null=False, blank=False)
    rating = models.FloatField()
    owner = models.CharField(max_length=200, null=False)

    class Meta:
        ordering = ['name']


class HotelPhoto(models.Model):
    photo = models.ImageField(upload_to='hotel_photos', null=True)
    hotel = models.OneToOneField(Hotel, on_delete=models.CASCADE, primary_key=True)

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        photo_serializer = HotelPhotoSerializer(data=request.data,
                                                context={'request': request})

        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

class HotelSerializer(serializers.HyperlinkedModelSerializer):
    photo = serializers.ImageField(source='hotelphoto.photo', read_only=True)

    class Meta:
        model = Hotel
        fields = ['url', 'id', 'name', 'address', 'rating', 'owner', 'photo']


class HotelPhotoSerializer(serializers.ModelSerializer):
    photo_url = serializers.SerializerMethodField()

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo', 'photo_url']

    def get_photo_url(self, obj):
        return self.context['request'].build_absolute_uri(obj.photo.url)

# Didn't change the HotelSerializer

class HotelPhotoSerializer(serializers.ModelSerializer):
    hotel = serializers.PrimaryKeyRelatedField(
            many=False,
            queryset=Hotel.objects.all())

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo']

    def create(self, validated_data):
        # Instead of creating a new HotelPhoto instance
        # changed the photo field from the Hotel instance
        hotel = validated_data.get('hotel')
        photo = validated_data.get('photo')
        hotel.hotelphoto.photo.save(photo.name, photo)
        hotel.save()
        return hotel.hotelphoto

class HotelPhotoUpload(APIView):
    parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        # I'm already sending the hotel id on the POST request
        photo_serializer = HotelPhotoSerializer(data=request.data)
        if photo_serializer.is_valid():
            photo_serializer.save()

            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

我忘了提到的一件事是，在上传照片之前，我总是向

hotels

端点（使用

HotelSerializer

）发送请求（POST或PUT）。因此，我不希望由于不存在酒店而在

photo/upload

端点上出现问题

移动客户端

不幸的是，无法发布多部分post请求内容，因为它太大了。但下面是使用改进2.5.0的客户机方法实现

// Sends the hotel id and the entire content of the photo file.
@Multipart
@POST(UPLOAD_ENDPOINT)
fun uploadPhoto(@Part("hotel") hotelId: RequestBody,
                @Part photo: MultipartBody.Part) : Call<UploadResult>

companion object {
    const val UPLOAD_ENDPOINT = "hotels/photo/upload/"
}

//发送酒店id和照片文件的全部内容。
@多部分
@POST（上传\u端点）
有趣的上传照片（@Part（“hotel”）hotelId:RequestBody，
@部分照片：MultipartBody.Part）：呼叫
伴星{
const val UPLOAD_ENDPOINT=“hotels/photo/UPLOAD/”
}

Foreignkey

和

OneToOneField

可以以相同的方式序列化。 这是你的

views.py

class HotelPhotoUpload(APIView):
    # parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        hotel = Hotel.objects.get(name=request.data.get('hotel'))
        request.data['hotel'] = hotel.id
        photo_serializer = HotelPhotoSerializer(data=request.data)
        # print(photo_serializer)
        if photo_serializer.is_valid():
            photo_serializer.save()
            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            # logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

class HotelSerializer(serializers.HyperlinkedModelSerializer):

    class Meta:
        model = Hotel
        fields = '__all__'


class HotelPhotoSerializer(serializers.ModelSerializer):
    hotel = serializers.PrimaryKeyRelatedField(many=False, queryset=Hotel.objects.all())

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo',]

    def create(self, validated_data):
        hotel_photo = HotelPhoto.objects.create(**validated_data)
        hotel_photo.save()
        return hotel_photo

serializers.py

class HotelPhotoUpload(APIView):
    # parser_classes = [FormParser, MultiPartParser]

    def post(self, request):
        hotel = Hotel.objects.get(name=request.data.get('hotel'))
        request.data['hotel'] = hotel.id
        photo_serializer = HotelPhotoSerializer(data=request.data)
        # print(photo_serializer)
        if photo_serializer.is_valid():
            photo_serializer.save()
            return Response(photo_serializer.data,
                            status=status.HTTP_201_CREATED)
        else:
            # logger.error(f'Error uploading image: {photo_serializer.errors}')
            return Response(photo_serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

class HotelSerializer(serializers.HyperlinkedModelSerializer):

    class Meta:
        model = Hotel
        fields = '__all__'


class HotelPhotoSerializer(serializers.ModelSerializer):
    hotel = serializers.PrimaryKeyRelatedField(many=False, queryset=Hotel.objects.all())

    class Meta:
        model = HotelPhoto
        fields = ['hotel', 'photo',]

    def create(self, validated_data):
        hotel_photo = HotelPhoto.objects.create(**validated_data)
        hotel_photo.save()
        return hotel_photo

我不明白为什么在你的

HotelSerializer

中有额外的字段，所以我把它删减了。如果您有特定的用例，请在代码中随意修改。而且您的

酒店

模型中没有主键，因此默认情况下，它将创建

id

字段，我假设每个

酒店名称

都是唯一的

邮递员要求：

来自管理部门的酒店数据：

---

谢谢你的回答，这很有帮助。现在它给了我一个关于

photo\u serializer.save（）

的

IntegrityError

，但我相信我可以解决这个问题。在对你的答案做了一些小改动之后，它就起了作用。在

create（）

方法中，我没有创建

HotelPhoto

实例，而是直接将图像保存在

Hotel

实例上，该实例由

validated\u data.get（'Hotel'）

使用

Hotel.HotelPhoto.photo.save（photo.name，photo）

Foreignkey

和

OneToOneField

使用drf可能会非常棘手，关于它的文档也不多。很高兴它至少起到了一些帮助：）如果它没有要求太多，你能用我所做的修改来调整你的答案，以便我能接受它吗？我不想在它部分工作的时候接受它，但我也不想在问题已经解决的时候不回答它。我会的，但是你用的是什么Django版本？