休眠查询不返回新数据

Question

I have a controller as follows:

SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
Transaction tx = null;
Session session = sessionFactory.openSession();
session.flush();
tx=session.beginTransaction();    

List<Plane> allPlanes = session.createQuery("from Planes").list();      
tx.commit();


session.close();

When I add a new record in the table through MySqlWorkBench GUI app, and hit this controller again, it doesn't pick up the latest record. Only after I restart tomcat will the new record be picked up. I've tried setting various caching options within the config file for hibernate and nothing seems to make a difference. How can I ensure that no matter where the data is updated that this query will always return a fresh copy of the data in the database?

Answer 1

You can't make changes to the database outside of JPA and expect JPA to know about it.

There is a way to get hibernate to reset, but you will have to have your database trigger and then send message over the network, or call a function manually.

On my systems, I have a manual reset that I invoke from a menu when I need to go behind the scenes and update the database directly, without restarting the JVM.

em.getEntityManagerFactory().getCache().evictAll();

Answer 2

How can I ensure that no matter where the data is updated that this query will always return a fresh copy of the data in the database?

As you limit your question to this query , you don't need to change your configuration or globally evict all caches.

Before invokation of org.hibernate.query.Query.list() simply invoke org.hibernate.query.Query.setCacheable(boolean) with false as argument for this query .