Python Django REST框架：使用嵌套对象值（而不是主键）创建和更新对象

我有两种型号一个国家一个办公室。office模型具有国家/地区模型的外键：

class Country(TranslatableModel):
    iso = models.CharField(
        max_length=2, verbose_name=_('iso code'),
        help_text="ISO 3166 ALPHA-2 code")
    translations = TranslatedFields(
        name=models.CharField(max_length=100, verbose_name=_('name')),
    )



class Office(models.Model):
    country = models.ForeignKey(
        Country, related_name='country', verbose_name=_('country'))

现在我想编写一个django rest框架序列化程序，只需发送

{“country”：“us”}

即可获得country模型的ForeingKey

如何实现这一点？

只读 只需将该表示发送到客户端（只读，不处理从其反序列化表示创建对象）

如您所见，它将从您的

office

实例中读取

country.iso

，该实例解析为

'us'

，例如，如果您的输出为

{'country'：'us'

，它将被放入名为

'country'

的序列化程序键中

可写嵌套字段 现在，为了完成此任务，让我们编写一个自定义的

OfficeSerializer.create（）

：

至于

OfficeSerializer.update（）

它是类似的：

def update(self, instance, validated_data):
    # instance is your Office object
    # You should update the Office fields here
    # instance.field_x = validated_data['field_x']

    # Let's grab the Country object again

    country_iso = validated_data.pop('country')
    country = Country.objects.get(iso=country_iso)

    # Update the Office object
    instance.country = country
    instance.save()

    return instance

---

是的，我知道如何显示国家代码，但如何通过POST/PUT API更新国家代码？（用户只需设置国家代码，无需ID，…）

def create(self, validated_data):
    # This expects an input format of {"country": "iso"}

    # Instead of using the ID/PK of country, we look it up using iso field
    country_iso = validated_data.pop('country')
    country = Country.objects.get(iso=country_iso)

    # Create the new Office object, and attach the country object to it
    office = Office.objects.create(country=country, **validated_data)

    # Notice I've left **validated_data in the Office object builder,
    # just in case you want to send in more fields to the Office model

    # Finally a serializer.create() is expected to return the object instance
    return office

def update(self, instance, validated_data):
    # instance is your Office object
    # You should update the Office fields here
    # instance.field_x = validated_data['field_x']

    # Let's grab the Country object again

    country_iso = validated_data.pop('country')
    country = Country.objects.get(iso=country_iso)

    # Update the Office object
    instance.country = country
    instance.save()

    return instance