1 会碰到”Not supported for DML operations [delete “问题，解决方法，加上Modifying注解
2 删除 更新没有反应 @Rollback(value = false)
@Rollback(value = false)
@Transactional
@Test
public void delUser(){
userDao.deleteByName("mljqqh");
long count = userDao.count();
System.out.println("count = " + count);
}