英文:
Hibernate 4.2, is many-to-one default cascade mapping none?
问题
我多次看到默认的 Hibernate cascade 是 "none"。即如果在 XML 映射中省略 cascade 标签，则与 "none" 相同。
今天，当类 A 对类 B 进行了多对一的更新操作时，观察到了奇怪的行为（甚至涉及到了类 B 的关联集合）。
添加 cascade="none" 解决了我的问题。
但我的问题仍然是一样的，即在 Hibernate 的多对一 XML 映射中，默认的级联是什么？
更新日期：2020 年 6 月 5 日 我怀疑默认的 cascade 有一些内部状态（不是 none），在这种模式下 Hibernate 处理具有组件的对象（按 Hibernate 的术语）。在调试会话期间，我观察到了一组“可管理”的对象，它们没有更改，但出于某种未知的原因被标记为“脏”。
TL;DR
XML 映射示例。AuditRecord 是对 User 类的多对一关系。对 AuditRecord 的持久化更新（有时！）User 类和相关集合。
<hibernate-mapping default-lazy="false" default-access="field">
<class name="package.AuditRecord" table="audit_record">
<id name="uuid" type="string">
<column name="uuid" sql-type="char(32)" not-null="true" />
<generator class="assigned" />
</id>
<many-to-one name="user" class="package.User" cascade="none">
<column name="user_uuid" sql-type="char(32)" not-null="false" />
</many-to-one>
<property name="success" type="boolean" not-null="true"/>
...
</class>
</hibernate-mapping>
实际持久化 AuditRecord 类的 Java 代码示例。
Transaction tx = session.beginTransaction();
try {
session.saveOrUpdate(pObject);
session.flush();
tx.commit();
} catch (Exception e) {
tx.rollback();
...
英文:
I saw many times that default hibernate cascade is "none". I.e. if you omit cascade tag in xml mapping it's the same as "none".
Today I observed strange behavior when class A that many-to-one to class B updated class B tables (and even dependent B's collections).
Adding cascade="none" fixed my issue.
But my question remains the same what is default cascade for many-to-one xml mapping in hibernate?
UPDATE 6.05.20 I suspect that default cascade has some internal (not none state) and in that mode hibernate process objects with components (in hibernate terms). During debug session I observed a list of "manageable" objects that are unchanged but mark as "dirty" for some unknown reason.
TL;DR
Sample of xml mapping. AuditRecord is many-to-one to User class. Persistent of AuditRecord updates (sometimes!) User class and dependent collections.
<hibernate-mapping default-lazy="false" default-access="field">
<class name="package.AuditRecord" table="audit_record">
<id name="uuid" type="string">
<column name="uuid" sql-type="char(32)" not-null="true" />
<generator class="assigned" />
</id>
<many-to-one name="user" class="package.User" cascade="none">
<column name="user_uuid" sql-type="char(32)" not-null="false" />
</many-to-one>
<property name="success" type="boolean" not-null="true"/>
...
</class>
</hibernate-mapping>
Sample of Java code that actually persist AuditRecord class.
Transaction tx = session.beginTransaction();
try {
session.saveOrUpdate(pObject);
session.flush();
tx.commit();
} catch (Exception e) {
tx.rollback();
...
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