SlugRelatedField自动创建关联表对象

例如有以下模型类,此处外键设置时blank和null约束条件必须设为True

class Book(models.Model):

    book_id = models.CharField(max_length=150)
    name = models.CharField(max_length=50)

    class Meta:
        
        db_table = 'book'

class Characters(models.Model):
    name = models.CharField(max_length=50)
    books =models.ForeignKey('Book',related_name='Characters',on_delete=models.CASCADE,blank=True,null=True)

    class Meta:
        
        db_table = 'characters'

​ DRF中利用SlugRelatedField字段进行反序列化时，假如想同时反序列化数据到关联表，可以重写 SlugRelatedFiedld类里的to_internal_value方法。前提:slug_field指定字段是唯一必传字段，先看看 to_internal_value代码。

class SlugRelatedField(RelatedField):
   """
   A read-write field that represents the target of the relationship
   by a unique 'slug' attribute.
   
  	以唯一字段表示表之间关系
   
   """
.......

def to_internal_value(self, data):
       try:
           return self.get_queryset().get(**{self.slug_field: data}) # 获取返回slug_field指定字段所传入的数据。
       except ObjectDoesNotExist:
           self.fail('does_not_exist', slug_name=self.slug_field, value=smart_str(data))
       except (TypeError, ValueError):
           self.fail('invalid')
.......

此处把self.get_queryset().get({self.slug_field: data})重写为get_or_create({self.slug_field: data})[0]即可。

# 重写to_internal_value方法
class SlugRelatedField(serializers.SlugRelatedField):

def to_internal_value(self, data):
        try:
            return self.get_queryset().get_or_create(**{self.slug_field: data})[0]
      
        except (TypeError, ValueError):
            self.fail('invalid')

# 定义书本序列化器
class BookSerializers(serializers.ModelSerializer):

    Characters=SlugRelatedField(many=True,queryset=Characters.objects.all(),slug_field='name')

    class Meta:
        model = Book
        fields = ['book_id','name','Characters']

传入数据校验并保存到数据库

data = {
    "book_id":1,
    "name":"神雕侠侣",
    "Characters":["杨过","小龙女","郭靖"]


}

bs = BookSerializers(data=data)
bs.is_valid()
bs.save()

结果如下图

本文地址：https://blog.csdn.net/jojotaro1/article/details/107533375