I use the session.beginTransaction() to start a new transaction.
After I save an object, and call transaction.rollback(), it works fine.
But if I try to run some query before that, the object is saved into database regardless I called rollback() or commit() later.

I'm using JDK1.5.0, Hibernate 2.1.7 and MySQL 4.1

Thank you for your help!

The code:
=======================================

Properties cp = new Properties();
cp.setProperty("hibernate.connection.driver_class", "com.mysql.jdbc.Driver");
cp.setProperty("hibernate.connection.url", "jdbc:mysql://localhost/server1?autoReconnect=true");
cp.setProperty("hibernate.connection.username", "localadmin");
cp.setProperty("hibernate.connection.password", "localadmin");
cp.setProperty("hibernate.connection.pool_size", "10");
cp.setProperty("hibernate.dialect", "net.sf.hibernate.dialect.MySQLDialect");
cp.setProperty("show_sql", "true");
cp.setProperty("hibernate.cache.provider_class", "net.sf.ehcache.hibernate.Provider");
cp.setProperty("jdbc.use_scrollable_resultset", "true");
sessionFactory = new Configuration().addProperties(cp).configure().buildSessionFactory();

Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
Employee ts = new Employee();
ts.setEmployeeCode("dec");
ts.setEmployeeName("dec");
session.save(ts);

/* The following 2 lines cause the problem */
Query query = session.createQuery("select e from Employee as e");
List result = query.list();



tx.rollback();

session.close();

Refer to http://www.hibernate.org/hib_docs/v3/reference/en/html/objectstate.html#objectstate-flushing.

The session may be flushed before the transaction is explicitly committed. One trigger is some queries. The documentation discusses how to change the flush mode to prevent this from happening.

However, I think you should consider not executing the query during the transaction (and therefore not needing to tinker with the flush mode). Queries can make a transaction take longer, and your thread may use more than its fair share of resources.[/url]

Thank you. It helps.

Make sure your using Innodb tables