1、打开PLSQL，用数据库用户登录，打开SQL窗口
2、例如：要删除表A中的，字段dinsetcode重复的行，剩下一行；参考如下delete from Awhere rowid in (select rowid,dinsetcode from A group by rowid,dinsetcode having count(dinsetcode) > 1 ）and rowid not in (select min(rowid) from A group by dinsetcode having count(dinsetcode)>1);删除了rowid中除了最小的其他行。