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python - Django Rest 框架说非必填字段是必需的

问题描述

背景故事

在 Django 中，我有模型

class Company(models.Model):
    name = models.TextField(null=False,unique=True)
    date_added = models.DateTimeField(auto_now_add=True)

class Address(models.Model):
    street = models.TextField()

class Person(models.Model ): 
    firstname = models.TextField()
    address = models.ForeignKey(Address,null= True,on_delete=models.SET_NULL)
    company = models.ForeignKey(Company,null=True,on_delete=models.SET_NULL)

每个人都有地址和公司。（均为非必填字段）

在 DRF 我有序列化程序。

class AddressSerializer(serializers.ModelSerializer):
    class Meta:
        model = Address
        fields = '__all__'

class CompanySerializer(serializers.ModelSerializer):

    class Meta:
        model = Company
        fields = "__all__"

class PersonSerializer(serializers.ModelSerializer):

    class Meta:
        model = Person
        fields = ('id', 'firstname',  'address','company')

    def to_representation(self, instance):
        response = super().to_representation(instance)
        response['address'] = AddressSerializer(instance.address).data
        response['company'] = CompanySerializer(instance.company).data
        return response

和视图集

class PersonViewSet(viewsets.ModelViewSet,UpdateModelMixin):
    queryset = Person.objects.all()
    serializer_class = PersonSerializer
    filter_backends = (OrderingFilter,DjangoFilterBackend,SearchFilter)
    filter_fields = ('id','company','firstname','middlename','lastname',)
    search_fields = ('firstname','middlename','lastname',)

class CompanyViewSet(viewsets.ModelViewSet,UpdateModelMixin):
    queryset = Company.objects.all()
    serializer_class = CompanySerializer
    filter_backends = (OrderingFilter,DjangoFilterBackend,SearchFilter)
    filter_fields = ('id','name',)
    search_fields = ('name',)

class AddressViewSet(viewsets.ModelViewSet,UpdateModelMixin):
    queryset = Address.objects.all()
    serializer_class = AddressSerializer
    filter_backends = [DjangoFilterBackend]
    filter_fields = ['id','street']

问题

将数据发布{"firstname":"foo"}到此序列化程序时，它会返回 400 错误代码。{"company": ["This field is required."]}.

奇怪的是，地址字段的设置方式看似与公司字段完全相同，但不会引发此错误。

为了使这项工作，您必须发布{"firstname":"foo","company":null}到序列化程序，考虑到地址字段工作正常，这似乎有点愚蠢。

有谁知道什么会导致这个问题以及如何防止这种情况发生？

标签： pythondjango

解决方案

您需要在 ForeignKey 构造函数中包含blank=True除了，如下所示：null=True

address = models.ForeignKey(Address,blank=True,null=True,on_delete=models.SET_NULL)
company = models.ForeignKey(Company,blank=True,null=True,on_delete=models.SET_NULL)

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