Django细致讲解多对多使用through自定义中间表方法

class Person(models.Model):
    name = models.CharField(max_length=128)
    def __str__(self):
        return self.name
class Group(models.Model):
    name = models.CharField(max_length=128)
    members = models.ManyToManyField(Person)
    def __str__(self):
        return self.name

from django.db import models
class Person(models.Model):
    name = models.CharField(max_length=128)
    def __str__(self):
        return self.name
class Group(models.Model):
    name = models.CharField(max_length=128)
    members = models.ManyToManyField(Person, through='Membership')
    def __str__(self):
        return self.name
class Membership(models.Model):
    person = models.ForeignKey(Person, on_delete=models.CASCADE)
    group = models.ForeignKey(Group, on_delete=models.CASCADE)
    date_joined = models.DateField()  # 进组时间
    invite_reason = models.CharField(max_length=64)  # 邀请原因

class PersonViews(ModelViewSet):
    queryset = Person.objects.filter()
    serializer_class = PersonSerializers
class GroupViews(ModelViewSet):
    queryset = Group.objects.filter()
    serializer_class = GroupSerializers
class MembershipViews(ModelViewSet):
    queryset = Membership.objects.filter()
    serializer_class = MembershipSerializers

from .models import Person, Group, Membership
class MembershipSerializers(serializers.ModelSerializer):
    class Meta:
        model = Membership
        fields = '__all__'
class PersonSerializers(serializers.ModelSerializer):
    class Meta:
        model = Person
        fields = '__all__'
class GroupSerializers(serializers.ModelSerializer):
    def to_representation(self, instance):
        representation = super(GroupSerializers, self).to_representation(instance)
        representation['members'] = []
        for i in PersonSerializers(instance.members, many=True).data:
            reason = MembershipSerializers(instance.membership_set.get(group=instance.id, person=i['id'])).data['invite_reason']
            i['invite_reason'] = reason
            representation['members'].append(i)
        return representation
    class Meta:
        model = Group
        fields = '__all__'

    # def to_representation(self, instance):
    #     representation = super(PersonSerializers, self).to_representation(instance)
    #     representation['reason'] = MembershipSerializers(instance.membership_set, many=True).data
    #     return representation