JPA Method in javax.persistence.EntityManager void persist( Object entity) Make an instance managed and persistent. Parameters: entity - entity instance Throws: EntityExistsException - if the entity already ex
传递给persist的实体是持久化的。这意味着，现在或以后在事务中，它将被写入数据库，并为该实体生成一...
传递给persist的实体是持久化的。这意味着，现在或以后在事务中，它将被写入数据库，并为该实体生成一...
Method Detail getCascadeAction protected CascadingAction getCascadeAction() Overrides: getCascadeAction in class JpaPersistEventListenerSkip navigation links Overview Package Class Use Tree Deprecated Index Help Red Hat JBoss Enterprise Application ...
In PersistObjectWithJPA class we create an EntityManagerFactory interface to interact with the entity manager factory for MyPeristenceUnit, that is defined in persistence.xml file. We create an EntityManager, using the createEntityManager() API method. Then, we create a new ProjectManager object. ...
尝试调用"persist"方法将实体模型保存到Spring MVC Web应用程序中的数据库时,我收到此错误.无法在互联网上找到任何与此特定错误相关的帖子或页面.似乎EntityManagerFactory bean出了问题,但我对Spring编程还是比较新的,所以对我来说似乎所有内容都已经初始化很好并且根据web中的各种教程文章....
is that we can use persist() method only within the boundary of a transaction, so it’s safeand takes care ofany cascaded objects.)。(发现原作者的第一点让人很疑惑,感觉是persist()不在事务中执行就会报错。经过测试,persist()在事务外运行不会报错,但是会插入数据到数据库。原作者的意思可能...
we can choose a compact database representation and make sure that changing the enum in any way will not break the existing mapping. Therefore, we add theshortName, which will be used as the database representation, as an additional property to the Enum. We also need a method to get the...
To avoid the NonUniqueObjectException, you need to use the merge method offered by the JPA EntityManager and inherited by the Hibernate Session as well.As explained in this article, the merge fetches a new entity snapshot from the database if there is no entity reference found in the ...
We can think of this method as a universal tool for making an objectpersistentregardless of its state, whether it’stransientordetached. 3.6.Refresh Therefreshmethod appears in both the Hibernate API and JPA. As the name suggests, therefreshmethod is called to refresh an entity in thepersistent...