sqlplus sys/密码 as sysdba
ALTER USER 账号 IDENTIFIED BY 新密码;
select * from (select rownum 别名 ,表名.* from 表名 ) where 别名<范围 and 别名>范围; 分页语句
例如：从员工表中查出 第四个---》第九个的所有员工
select * from (select rownum num , emp.* from emp ) where num<9 and num>4;
select * from (select rownum num , emp.* from emp where rownum <9) where num>4;