DRF创建API中多对多字段的问题答案

【问题标题】：Problem with many to many fieds in DRF create APIDRF创建API中多对多字段的问题
【发布时间】：2020-03-11 10:24:22
【问题描述】：

当我想保存我的模型的一个实例时，多对多的字段没有被保存。我尝试了以下代码：

型号：

class Attachment(models.Model):
    test = models.TextField()


class PlanComment(models.Model):
    attachment = models.ManyToManyField('Attachment', blank=True)
    comment = models.TextField()

序列化器：

class AttachmentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Attachment
        fields = ['test']


class PlanCommentSerializer(serializers.ModelSerializer):
    attachment = AttachmentSerializer(many=True, read_only=True)

    class Meta:
        model = PlanComment
        fields = [
            'id',
            'attachment',
        ]

观看次数：

class PlanCommentViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows plan comment to be viewed or edited.
    """
    queryset = PlanComment.objects.all().order_by('-id')
    serializer_class = PlanCommentSerializer

我的参数：

{
    "attachment": [1],
    "comment": "Test"
}

【问题讨论】：

删除read_only=True
@ArakkalAbu 未设置 read_only 时，附件不能是 params 中的 PK 列表。

标签： python django python-3.x django-rest-framework

【解决方案1】：

我将我的 PlanCommentSerializer 更改为以下代码，它工作正常 =)

class PlanCommentSerializer(serializers.ModelSerializer):
    def __init__(self, instance=None, **kwargs):
        if instance:
            setattr(self.Meta, 'depth', 1)
        else:
            setattr(self.Meta, 'depth', 0)
        super(PlanCommentSerializer, self).__init__(instance, **kwargs)

    class Meta:
        model = PlanComment
        fields = '__all__'
        depth = 0

【讨论】：