oracle中删除一个用户

1、查询用户的session:

select SID,SERIAL# from V$SESSION where usename='u1';

2、kill掉用户u1的session:

alter system kill session 'SID,SERIA#';

3、删除掉用户u1

drop user u1 cascade;

4、查看当前数据库的用户

select username from V$SESSION where TYPE='USER';