Django Rest Framework 更新不保存更改

Question

我有两个通过一对一字段关联的模型，我想创建一个REST 服务来管理它们，就像它们在哪里一样。 post 到目前为止运行良好，并且在两个模型中都创建了新实例，但 put 方法什么也不做。它不会引发任何错误或任何事情，只是保持数据不变。

这些是我的模型：

class Company(models.Model):
    name = models.CharField(max_length=40)
    legal_name = models.CharField(max_length=100)
    url = models.URLField()
    address = models.TextField(max_length=400)

    def __str__(self):
        return "[{}]{}".format(self.id, self.name)

class Hotel(models.Model):
    company = models.OneToOneField('Company', on_delete=models.CASCADE, primary_key=True)
    code = models.CharField(max_length=10)
    city = models.ForeignKey('City', on_delete=models.PROTECT, related_name='city_hotels')
    category = models.ForeignKey('HotelCategory', on_delete=models.PROTECT, related_name='category_hotels')
    capacity = models.IntegerField()
    position = models.DecimalField(max_digits=11, decimal_places=2, default=0.00)
    in_pickup = models.BooleanField(default=False)

    def __str__(self):
        return self.company.name

这是我的视图集：

class HotelViewSet(viewsets.ModelViewSet):
    queryset = models.Hotel.objects.all()
    serializer_class = serializers.HotelSerializer

这些是我的序列化程序：

class CompanySerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = models.Company
        fields = ('id', 'name', 'legal_name', 'url', 'address')

class HotelSerializer(serializers.HyperlinkedModelSerializer):
    company = CompanySerializer()
    class Meta:
        model = models.Hotel
        fields = ('company', 'code', 'city', 'category', 'capacity', 'position', 'in_pickup')

    def create(self, validated_data):
        company_data = validated_data.pop('company')
        new_company=models.Company.objects.create(**company_data)
        hotel = models.Hotel.objects.create(company=new_company, **validated_data)

        return hotel

    def update(self, instance, validated_data):

        company = models.Company(
            id=instance.company.id,
            name=instance.company.name,
            legal_name=instance.company.legal_name,
            url=instance.company.url,
            address=instance.company.address
        )

        company.save()
        instance.save()

       return instance

Answer 1

我发现instance带有原始数据，validated_data带有新数据。我正在保存原始数据。

我不得不用validated_data 数据替换instance 数据，然后保存instance：

def update(self, instance, validated_data):

    company_data = validated_data.pop('company')
    company = models.Company.objects.get(id=instance.company.id)
    company.name = company_data.get('name')
    company.legal_name = company_data.get('legal_name')
    company.tax_id = company_data.get('tax_id')
    company.url = company_data.get('url')
    company.address = company_data.get('address')

    instance.company = company
    instance.code = validated_data.get('code', instance.code)
    instance.city = validated_data.get('city', instance.city)
    instance.category = validated_data.get('category', instance.category)
    instance.capacity = validated_data.get('capacity', instance.capacity)
    instance.position = validated_data.get('position', instance.position)
    instance.in_pickup = validated_data.get('in_pickup', instance.in_pickup)
    instance.is_active = validated_data.get('is_active', instance.is_active)

    company.save()
    instance.save()

    return instance

put 方法现在效果很好。

Answer 2

您正在创建 company 的新实例，而不是更新属于 Hotel 实例的实例。

company = Company.objects.get(id=instance.company.id)
company.name = instance.company.name
company.legal_name = instance.company.name
company.url = instance.company.url
company.address = instance.company.address
company.save()
instance.save()