如何删除django中级联的一对一相关模型? [英] How to delete one-to-one relating models cascading in django?

问题描述

我在 Django(1.8.5) 中定义了以下模型:

I have the below models defined in Django(1.8.5):

class PublishInfo(models.Model):
    pass

class Book(models.Model):
    info = models.OneToOneField(
        PublishInfo, on_delete=models.CASCADE)

class Newspaper(models.Model):
    info = models.OneToOneField(
        PublishInfo, on_delete=models.CASCADE)

其中 Book 和 NewsPaper 与 OneToOneField 共享相同的模型 PublishInfo，这实际上是唯一的外键.

Where Book and NewsPaper shares a same model PublishInfo as a OneToOneField, which is in fact a unique foreign key.

现在，如果我删除一个 PublishInfo 对象，相关的 Book 或 Newspaper 对象将被级联删除.

Now, if I delete a PublishInfo Object, the relating Book or Newspaper object is deleted with cascading.

但实际上，当我删除Book 或Newspaper 对象时，我想删除PublishInfo 对象级联.这是我可以打电话的方式.

But in fact, I want to delete the PublishInfo object cascading when I delete the Book or Newspaper object. This way is the way I may call.

在这种情况下，有没有什么好的方法可以在反向自动级联删除?如果是，能否解释一下?

Is there any good way to automatically cascading the deletion in the reverse direction in this case? And, if yes, could it be explained?

推荐答案

您附上 post_delete 向您的模型发送信号，以便在删除 Book 或 Newspaper 的实例时调用它:

You attach post_delete signal to your model so it is called upon deletion of an instance of Book or Newspaper:

from django.db.models.signals import post_delete
from django.dispatch import receiver

@receiver(post_delete, sender=Book)
def auto_delete_publish_info_with_book(sender, instance, **kwargs):
    instance.info.delete()

@receiver(post_delete, sender=Newspaper)
def auto_delete_publish_info_with_newpaper(sender, instance, **kwargs):
    instance.info.delete()

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