使用 Hibernate (hbm2ddl) 克隆表的定义
在我的休眠应用程序中，有一个注释驱动的对象：AuditEvent。 它非常简单，没有外键关系。 我通过将旧条目移动到另一个表 OldAuditEvent 来归档此表中的旧条目，该表是 AuditEvent 表的克隆。
现在，我们使用 hbm2ddl（在带注释的数据模型上）为整个应用程序生成 DDL，并手动复制/粘贴 AuditEvent 表并更改其名称以创建 OldAuditEvent。
我想自动化构建过程，有什么方法可以告诉 hbb2ddl：“嘿，拿这个实体，将表名更改为 X 并重新生成它的 DDL”？
更新： 我能够通过您概述的方法来实现此目的。 唯一的麻烦是获取 AnnotationSessionFactoryBean，因为它是一个工厂 bean，spring 只会给你它工厂的输出。 我创建了 ConfigExusingAnnotationSessionFactoryBean （扩展 AnnotationSessionFactoryBean）来通过静态公开 Bean 工厂——有点黑客，但我想做的就是运行构建时任务。
Configuration cfg = ConfigExposingAnnotationSessionFactoryBean.s_instance.getConfiguration();
PersistentClass pClass = cfg.getClassMapping("com.myco.LoginAttempt");
pClass.getTable().setName("ArchiveLoginAttempt");
Dialect dialect = Dialect.getDialect(ConfigExposingAnnotationSessionFactoryBean.s_instance.getHibernateProperties());
// only output create tables, not indexes or FK
for (String s : cfg.generateSchemaCreationScript( dialect )) {
if (s.contains("create table") && s.contains("Archive")) {
m_outstream.print(s);
m_outstream.println(";");
}
}
In my hibernate application there is annotation driven object: AuditEvent. Its very simple and has no foreign key relationships. I archive old entries in this table by moving them to another table OldAuditEvent, which is a clone of the AuditEvent table.
Right now we generate the DDL for the entire application using hbm2ddl (on our annotated datamodel) and manually copy/paste the AuditEvent table and change its name to create OldAuditEvent.
I want to automate the build process, is there any way to tell hbb2ddl: "hey take this entity, change the table name to X and regenerate it's DDL"?
Update:
I was able to get this working by the approach you outlined. The only trouble was getting at the AnnotationSessionFactoryBean since it is a factory bean and spring will only give you the output of its factory. I created ConfigExposingAnnotationSessionFactoryBean (extending AnnotationSessionFactoryBean) to expose the bean factory through a static -- sort of a hack but all I want to do is run a build time task.
Configuration cfg = ConfigExposingAnnotationSessionFactoryBean.s_instance.getConfiguration();
PersistentClass pClass = cfg.getClassMapping("com.myco.LoginAttempt");
pClass.getTable().setName("ArchiveLoginAttempt");
Dialect dialect = Dialect.getDialect(ConfigExposingAnnotationSessionFactoryBean.s_instance.getHibernateProperties());
// only output create tables, not indexes or FK
for (String s : cfg.generateSchemaCreationScript( dialect )) {
if (s.contains("create table") && s.contains("Archive")) {
m_outstream.print(s);
m_outstream.println(";");
}
}
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这是可行的，但相当混乱，而且在这种情况下很可能不值得。
您需要动态更改 Hibernate 的配置 SessionFactory 构建之前的对象。 如果您使用 Spring，这可以通过覆盖
AnnotationSessionFactoryBean的postProcessAnnotationConfiguration()方法来完成； 否则，您只需要在调用buildSessionFactory()之前使用Configuration对象来完成此操作。您可以通过configuration.getMappings() 访问类/表映射。 然后，您需要通过
getTable()找到表映射，通过addTable()创建具有新名称的副本，并通过 表 API。然后，您可以通过
Configuration对象的generateSchemaCreationScript()或generateSchemaUpdateScript()方法生成 DDL 脚本。正如我所说，在这种情况下可能不值得:-)
It's doable but rather messy and, most likely, not worth it in this case.
You'll need to dynamically alter Hibernate's Configuration object before SessionFactory is built. I you're using Spring, this can be done by overriding
postProcessAnnotationConfiguration()method ofAnnotationSessionFactoryBean; otherwise you'll just need to do it using yourConfigurationobject prior to invokingbuildSessionFactory()on it.You can get access to class / table mappings via
configuration.getMappings(). You will then need to find your table mapping viagetTable(), create a copy with new name viaaddTable()and replicate all columns / keys via Table API.You can then generate the DDL script via
generateSchemaCreationScript()orgenerateSchemaUpdateScript()methods ofConfigurationobject.As I said, probably not worth it in this case :-)