阅读:47
本文主要看序列化
以下公式二选一:
从表属性写 主表s属性 = 主表serializers()
主表属性写 从表_set = 从表serializers(many=True, read_only=True)
主表 主人 owner
从表 宠物 pet
我有一个API端点返回宠物及其主人。
每位所有者都有一个名称,一个或多个宠物
每只宠物都有一个名字,一个所有者
示例Django模型:
class Owner(models.Model):
name = models.CharField(max_length=200)
class Pet(models.Model):
owner = models.ForeignKey(Owner, on_delete=models.CASCADE)
name = models.CharField(max_length=200)
我已将我的API配置为返回JSON数据,如下所示:
[
{
"id": 2,
"name": "Scotch",
"owner": {
"id": 2,
"name": "Ben"
}
},
{
"id": 3,
"name": "Fluffy",
"owner": {
"id": 1,
"name": "Fred"
}
},
{
"id": 1,
"name": "Spot",
"owner": {
"id": 1,
"name": "Fred"
}
}
]
示例DRF序列化程序:
```python
class OwnerSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = Owner
fields = ("id", "name")
class PetSerializer(serializers.HyperlinkedModelSerializer):
owner = OwnerSerializer()
class Meta:
model = Pet
fields = ("id", "name", "owner")
虽然这一切都很精致,但我真的希望有一个能够返回所有者及其宠物列表的端点。所以我得到了这些数据:
[
{
"id": 1,
"name": "Fred",
"pets": [
{ "id": 1, "name": "Spot" },
{ "id": 3, "name": "Fluffy" }
]
},
{
"id": 2,
"name": "Ben",
"pets": [
{ "id": 2, "name": "Scotch" }
]
}
]
我如何实现这一输出?
您需要将pet_set
字段添加到OwnerSerializer
,如下所示:
class PetSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = Pet
fields = ("id", "name")
class OwnerSerializer(serializers.HyperlinkedModelSerializer):
pet_set = PetSerializer(many=True, read_only=True)
class Meta:
model = Owner
fields = ("id", "name", "pet_set")
这将有效,因为在您的情况下,多对一关系默认反向查找名称为<model>_set
或pet_set
。您可以使用related_name:
进行更改
class Pet(models.Model):
owner = models.ForeignKey(Owner, related_name='pets', on_delete=models.CASCADE)
在这种情况下,您可以在序列化程序中使用pets
名称:
class OwnerSerializer(serializers.HyperlinkedModelSerializer):
pets = PetSerializer(many=True, read_only=True)
现在在OwnerListView中,您可以使用这个新的序列化程序:
class OwnerListView(ListAPIView):
queryset = Owner.objects.all()
serializer_class = OwnerSerializer
更改/添加 serializer.py
,如下所示
class PetSerializer(serializers.ModelSerializer):
class Meta:
model = Pet
fields = ("id", "name")
class OwnerNewSerializer(serializers.ModelSerializer):
pets = PetSerializer(many=True, source='pet_set')
class Meta:
model = Owner
fields = ('id', 'name', 'pets')
和 views.py
class OwnerAPI(viewsets.ModelViewSet):
queryset = Owner.objects.all()
serializer_class = OwnerNewSerialize