SQL> drop user lisi;drop user lisiORA-01940: 无法删除当前连接的用户SQL> select username,sid,serial# from v$session where username is not null;USERNAME SID SERIAL#------------------------------ ---------- ----------AAA 12 28AAA 13 186AAA 21 204AAA 24 45AAA 143 206LISI 145 4876 rows selectedSQL> select username,sid,serial# from v$session where username='LISI';USERNAME SID SERIAL#------------------------------ ---------- ----------LISI 145 487SQL> alter system kill session '145,487';System alteredSQL> drop user lisi cascade;SQL> User droppedSQL> select username,sid,serial# from v$session where username='LISI';USERNAME SID SERIAL#------------------------------ ---------- ----------LISI 145 487SQL> select username,sid,serial# from v$session where username is not null;USERNAME SID SERIAL#------------------------------ ---------- ----------AAA 12 28AAA 21 204AAA 24 45AAA 143 206LISI 145 487SQL> alter system kill session'145,487';System alteredSQL> drop user lisi cascade;drop user lisi cascadeORA-01918: 用户 'LISI' 不存在SQL> select username,sid,serial# from v$session where username is not null;USERNAME SID SERIAL#------------------------------ ---------- ----------AAA 12 28AAA 21 204AAA 24 45AAA 143 206LISI 145 487SQL> select username,sid,serial# from v$session where username is not null;USERNAME SID SERIAL#------------------------------ ---------- ----------AAA 12 28AAA 21 204AAA 24 45AAA 143 206LISI 145 487