我与Hibernate和Oracle合作.我使用了以下代码:
if (null != sessionFactory) {
Session s = currentSession.get();
if ((null == s) || !s.isOpen()) {
s = sessionFactory.openSession();
currentSession.set(s);
} else {
try {
HibernateWork hibernateWork = new HibernateWork("SELECT 1 FROM DUAL");
s.doWork(hibernateWork);
} catch (Exception e) {
s = sessionFactory.openSession();
currentSession.set(s);
}
}
return s;
}
我想对PostgreSQL做同样的事情,但PostgreSQL不支持"FROM dual"语法.我想知道dual在PostgreSQL中的等价性.