python-3.x - Django多对一关系将数据添加到多方

Question

我有两个像下面这样的模型。我正在使用 Django restframework。

class Family(models.Model):
    name= models.CharField(max_length=100)

class Parishioner(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=30)
    family = models.ForeignKey(Family, on_delete=models.CASCADE)

有我的 View 集

class FamilyViewSet(viewsets.ModelViewSet):
    queryset = Family.objects.all()
    serializer_class = FamilySerializer
    authentication_classes = (TokenAuthentication,)
    permission_classes = (IsAuthenticated,)

class ParishionerViewSet(viewsets.ModelViewSet):
    queryset = Parishioner.objects.all()
    serializer_class = serializers.ParishionerSerializer
    authentication_classes = (TokenAuthentication,)
    permission_classes = (IsAuthenticated,)

这些是我的序列化程序

class FamilySerializer(serializers.ModelSerializer):

    class Meta:
        model = Family
        fields = ('id', 'name')
        read_only_fields = ('id',)


class ParishionerSerializer(serializers.ModelSerializer):
    class Meta:
        model = Parishioner
        fields = ('id', 'first_name', 'last_name', 'family')
        read_only_fields = ('id',)
        depth = 1

所以基本上 Parishioner可以有一个 Family . Family有多个 members(Parishioners)目前我必须去所有 Parishioners并选择 Family .
是否可以添加一个名为 members 的字段？至 Family模型，其中成员是 Array的 Existing Parishioners ?
或者有没有其他方法可以解决这个问题？

Answer 1

在数据库端这样做是个坏主意，因为这意味着数据库不再检查它。
但是您可以在序列化程序中轻松执行此操作。我们通过添加 ParishionerSerializer 的实例来做到这一点。到 FamilySerializer .我们需要定义 ParishionerSerializer之前FamilySerializer ，否则，该标识符尚未分配:

class ParishionerSerializer(serializers.ModelSerializer):
    class Meta:
        model = Parishioner
        fields = ('id', 'first_name', 'last_name', 'family')
        read_only_fields = ('id',)
        depth = 1


class FamilySerializer(serializers.ModelSerializer):
    parishioner_set = ParishionerSerializer(many=True, read_only=True)

    class Meta:
        model = Family
        fields = ('id', 'name')
        read_only_fields = ('id',)

您可以将其重命名为 members在模型层，然后相应地更新序列化器，或仅在子序列化器中。
选项 1:使用 related_name=…我们可以将关系重命名为 memebers通过为 related_name=… [Django-doc] 指定一个值:

class Parishioner(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=30)
    family = models.ForeignKey(
        Family,
        on_delete=models.CASCADE,
        related_name='members'
    )

那么序列化器因此使用 member反而:

class FamilySerializer(serializers.ModelSerializer):
    members = ParishionerSerializer(many=True, read_only=True)

    class Meta:
        model = Family
        fields = ('id', 'name')
        read_only_fields = ('id',)

选项 2:使用 source=… 重命名序列化程序
我们也只能在序列化器级别指定它，通过指定 source=… parameter [drf-doc] :

class FamilySerializer(serializers.ModelSerializer):
    members = ParishionerSerializer(
        source='parishioner_set',
        many=True,
        read_only=True
    )

    class Meta:
        model = Family
        fields = ('id', 'name')
        read_only_fields = ('id',)