保存相關對象

Question

我在使用Django Rest Framework保存相關對象時遇到了一些麻煩。這裏是我的模型

# models.py 
class PowerStatus(models.Model): 
    status = models.CharField(max_length=50) 

class VirtualMachine(models.Model): 
    power_status = models.ForeignKey(PowerStatus, verbose_name='Power status') 

我的串行器看起來像這樣：

# serializers.py 
class PowerStatusSerializer(serializers.ModelSerializer): 
    status = serializers.CharField(max_length=30) 

    class Meta: 
     model = PowerStatus 

class VMSerializer(serializers.ModelSerializer): 
    power_status = PowerStatusSerializer() 

    class Meta: 
     model = VirtualMachine 

    def create(self, validated_data): 
     power_status_data = validated_data.pop('power_status') 
     vm = VirtualMachine.objects.create(**validated_data) 
     PowerStatus.objects.create(vm=vm, **power_status_data) 

     return vm 

錯誤，那是我得到的是：django.db.utils.IntegrityError: (1048, "Column 'power_status_id' cannot be null")

我下面http://www.django-rest-framework.org/api-guide/serializers/#dealing-with-nested-objects但我做錯了什麼。

：編輯：

與Column cannot be null處理，另一個問題出現後，

ValueError: Cannot assign "OrderedDict([('status', 'Running')])": "VirtualMachine.power_status" must be a "PowerStatus" instance.

Answer 1

在的虛模型通空= True以power_status字段。

class VirtualMachine(models.Model): 
    power_status = models.ForeignKey(PowerStatus, verbose_name='Power status', null=True)