mongoengine reverse_delete_rule 的工作方向是什么？

Question

如果我有以下两个模型：

class User(Document):
    ...

class Profile(Document):
    user = ReferenceField(reverse_delete_rule=CASCADE)

删除用户实例是否会删除其配置文件？删除其个人资料会删除用户吗？

documentation:

中似乎有错误

class Employee(Document):
    ...
    profile_page = ReferenceField('ProfilePage', reverse_delete_rule=mongoengine.NULLIFY)
The declaration in this example means that when an Employee object is removed, the ProfilePage that belongs to that employee is removed as well. If a whole batch of employees is removed, all profile pages that are linked are removed as well.

代码中使用了NULLIFY，但是解释说明使用了CASCADE。还是我误会了什么？

Answer 1

删除用户实例会删除其配置文件。这就是 reverse_delete_rule=CASCADE 的工作方式。就像在关系数据库中一样。

您可以查看此代码：

from mongoengine import connect, Document, ReferenceField, CASCADE


connect('test_cascade')


class User(Document):
    pass


class Profile(Document):
    user = ReferenceField(User, reverse_delete_rule=CASCADE)


user = User().save()
profile = Profile(user=user).save()

user.delete()

assert Profile.objects.count() == 0

他们还更新了文档，现在是另一种方式：

class ProfilePage(Document):
    ...
    employee = ReferenceField('Employee', reverse_delete_rule=mongoengine.CASCADE)
The declaration in this example means that when an Employee object is removed, the ProfilePage that references that employee is removed as well. If a whole batch of employees is removed, all profile pages that are linked are removed as well.

mongoengine reverse_delete_rule 的工作方向是什么？

In what direction does mongoengine reverse_delete_rule work?

python

mongodb

mongoengine