Question

我在Entity和EntityGroup之间建立了M2M关系，我想将相应的实体索引保存到EntityGroup，就像将实体数组保存到数据库一样。

由于我在模型中使用了带有附加字段index的自定义模式，因此我需要将index序列化为响应的相应entity，我应该如何实现呢？

我是django和django-rest-framework的新手，在经过几次Google搜索后，似乎没有类似的M2M示例。我的想法是，序列化程序只能序列化具有ForeignKey关系的唯一模型的字段，视图集可以具有基于queryset的自定义模型，该模型可以合并几个模型的关系。因此，我需要在内部使用自定义queryset来实现可扩展的视图集吗？

这是我的代码：

models.py

class Entity(models.Model):
    uuid = models.CharField()
    name = models.CharField()

class EntityGroup(models.Model):
    name = models.CharField()
    entities = models.ManyToManyField(Entity,
        through='EntityGroupRelationship',
        through_fields=('group', 'entity'),
        related_name='groups'
    )

class EntityGroupRelationship(models.Model):
    entity = models.ForeignKey(Entity, on_delete=models.CASCADE)
    group = models.ForeignKey(EntityGroup, on_delete=models.CASCADE)
    index = models.PositiveIntegerField()

serializers.py

class EntitySerializer(serializers.ModelSerializer):
    class Meta:
        model = Entity
        fields = '__all__'

class EntityGroupRelationshipSerializer(serializers.ModelSerializer):
    class Meta:
        model = EntityGroupRelationship
        fields = '__all__'

class EntityGroupSerializer(serializers.ModelSerializer):
    entities = EntitySerializer(many=True)

    class Meta:
        model = EntityGroup
        fields = '__all__'

views.py

class EntityGroupViewSet(BaseModelViewSet):
    queryset = EntityGroup.objects.all()
    serializer_class = EntityGroupSerializer

class EntityGroupRelationshipViewSet(BaseModelViewSet):
    queryset = EntityGroupRelationship.objects.all()
    serializer_class = EntityGroupRelationshipSerializer

当前响应

[
    {
        "id": 1,
        "entities": [{
            "id": 1,
            "name": "",
        }]
    },
    ...
]

预期的响应

[
    {
        "id": 1,
        "entities": [
            {
                "index": 1,
                "info": {
                    "id": 1,
                    "name": "",
                }
            }
        ]
    },
    ...
]

Answer 1

您为此使用了不正确的序列化程序。使用EntityGroupRelationshipSerializer代替EntitySerializer。另外，您还需要传递正确的fields

class EntitySerializer(serializers.ModelSerializer):
    class Meta:
        model = Entity
        fields = '__all__'

class EntityGroupRelationshipSerializer(serializers.ModelSerializer):
    entity = EntitySerializer()
    class Meta:
        model = EntityGroupRelationship
        fields = ('index', 'entity')

class EntityGroupSerializer(serializers.ModelSerializer):
    entities = EntityGroupRelationshipSerializer(many=True) # here should be EntityGroupRelationshipSerializer

    class Meta:
        model = EntityGroup
        fields = '__all__'

DRF中ManyToManyField的自定义序列化程序和ViewSet

1 个答案: