hibernate不知道怎么删除？

[kurorohisoka]

数据库表：CUSTOMER
字段：ID，NAME,PASSWOED
代码：
public static void main(String[] args) {
Configuration conf = new Configuration().configure();
SessionFactory sf = conf.buildSessionFactory();
Session se = sf.openSession();
List<Customer> list=null;
Customer cs=null;
Transaction tr = se.beginTransaction();
CustomerDAO dao = new CustomerDAO();
list = dao.findByProperty("name", "smile1");//mysql中已经存在的一个名为smile1的数据
list.listIterator().hasNext();
Iterator<Customer> it = list.iterator();
while(it.hasNext()){
cs=(Customer)it.next();
System.out.println(cs.getName());//查看是否取到了数据
dao.delete(cs);
}
tr.commit();
}
//CustomerDAO中的delete函数
public void delete(Customer persistentInstance) {
log.debug("deleting Customer instance");
try {
getSession().delete(persistentInstance);
log.debug("delete successful");
} catch (RuntimeException re) {
log.error("delete failed", re);
throw re;
}
}
显示已经查询到数据，可是到数据库看，smile1数据并没有删除，这是为什么？是否与持久化对象有关？我是新手，请指点，谢谢！

[Shine_Panda]

Hibernate 的缓存没有清理.
代码改一下.
try {
Session session = getSession();
session.delete(persistentInstance);
session.beginTrasaction().commit();
log.debug("delete successful");
} catch (RuntimeException re) {
log.error("delete failed", re);
throw re;
}

[kurorohisoka]

改后的代码与我之前的代码没有本质的变化呀，为什么缓存没有清理，在代码中那体现了清理缓存了？谢谢指教