ORA-01858: a non-numeric character was found where a numeric was expected

程序操作Oracle数据库时，出现“ORA-01858: a non-numeric character was found where a numeric was expected”错误。

原因是语句中包含“lurudate = TO_DATE('197001ull','yyyymmddhh24mi')”，里面的时间格式不正确。

以后写程序时一定要加强对数据合法性的校验。