Hibernate 中的级联是什么? [英] What is cascading in Hibernate?

问题描述

Hibernate 中的级联是什么?我在 map 标签中看到了一个 cascade 属性.这是什么意思?

What is cascading in Hibernate ? There is a cascade attribute I have seen in the map tag. What is it meant for?

比如cascade = all 是什么意思?还有其他我喜欢的属性
cascade="none|save-update|delete|all-delete-orphan|delete-orphan".

Like what does cascade = all mean? There are other attributes I read like
cascade="none|save-update|delete|all-delete-orphan|delete-orphan".

推荐答案

级联是关于持久性操作，涉及一个对象通过关联传播到其他对象.级联可以应用于各种 Hibernate 操作，并且它通常是可传递的.定义关联的注解的cascade=..."属性表示该关联应该级联哪些操作.

Cascading is about persistence actions involving one object propagating to other objects via an association. Cascading can apply to a variety of Hibernate actions, and it is typically transitive. The "cascade=..." attribute of the annotation that defines the association says what actions should cascade for that association.

Cascade = "all" 表示应用所有主要级联类型.从 Hibernate 5.3 开始，这些类型是:

Cascade = "all" means to apply all primary cascade types. As of Hibernate 5.3, these types are:

• 删除"/移除"，
• 分离"/驱逐"，
• 合并"，
• 锁"，
• 坚持"，
• 刷新"，
• 复制"，
• save_update"/更新"

(其中一些级联类型名称已过时和/或已弃用.)

(Some of those cascade type names are old and/or deprecated.)

还有另外三种复合类型:

There are three more compound types:

• all_delete_orphan" - 与all"的意思相同，外加允许删除被级联孤立的实体.
• delete_orphan" - 表示删除"加上孤立删除.
• none" - 表示没有级联.

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