使用 Hibernate @Index Annotation 在 DB 上创建索引 [英] Creating Indexes on DB with Hibernate @Index Annotation

问题描述

我的项目有注释驱动的休眠功能.

I have annotation-driven hibernate capabilies on my project.

现在我想在列上创建索引.我当前的列定义是

Now I want to create an index over a column. My current column definition is

@NotNull
@Column(name = "hash")
private String hash;

我在这里添加了 @Index 注释.

and I add @Index annotation here.

@NotNull
@Column(name = "hash")
@Index(name="hashIndex")
private String hash;

然后删除表并重新启动Tomcat服务器.实例化服务器后，创建了表，但在以下查询中看不到新索引.

and then DROP TABLE and restart Tomcat server. After the server is instantiated, the table is created but I can't see new index on following query.

SHOW INDEX FROM tableName

期望用新索引构造表.我在 MySQL 中使用 InnoDB.

It is expected to construct table with new index. I am using InnoDB with MySQL.

推荐答案

有趣的是，在我的 Hibernate 配置中，我使用了 hibernate.hbm2ddl.auto=update.

Interestingly, in my Hibernate configuration I was using hibernate.hbm2ddl.auto=update.

这个修改了一个现有的数据库.我手动删除表 tableName 并重新启动 Tomcat，并且该表已构建但未创建索引.

This one modifies an existing database. I was manually DROPping the table tableName and restarting Tomcat and the table had been constructed but index was not being created.

然而，我制作了 hibernate.hbm2ddl.auto=create，它在每次 webapp 实例化时重新创建数据库，它删除了我所有的数据库并重建了 - 地狱是的 - 我的新索引已经已创建！

However, I made hibernate.hbm2ddl.auto=create which re-creates database upon each instantiation of webapp, it dropped all my database and rebuilt back and -hell yeah- my new index has been created!

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