java - Hibernate select before update

Question

In my work i'm using spring with exidirect, hibernate on the server side and extjs on client side. When i post a form, on the server side spring converts it to the entity. Entity has a id field, that supposes update operation. I'm calling service save method, but instead one sql update query i get many many select queries and just then update. It takes much time. And there is no need for this operation. I was looking similar questions and was trying to use persist method. This case i get error: detached entity passed to persist.

I do not have enough experience of hibernate. May be i need to configure related entities (OneToMany, ManyToOne and cascade types). Entities are generated by Spring roo tool.

Any suggestions ? Thank you.

Answer 1

这不是您问题的最终答案，但我希望它可以作为高级指南。

当您使用 Spring 创建一个实体时，该实体被分离并且 Hibernate 执行这些 SELECT 语句，因为它需要在持久化之前附加您的实体。此外，据我所知，任何附加实体的尝试都会触发 SELECT 语句。因此，我坚信如果没有这些 SELECT 语句，就没有任何方法可以保存/持久化分离的实体（我在这里可能错了）。

如果您担心性能，您可以尝试向您的应用程序添加一些缓存功能。此外，您还可以仅针对性能受到影响的操作包含 JDBC 解决方案。

Answer 2

向实体添加 @SelectBeforeUpdate(false) 注释。