Question

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：

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？

Answer 1

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

Answer 2

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

DRF多对一反向查找

2 个答案: