最初我连接到用户u1。
connect u1/p1;
select user from dual;
USER:
----
U1
现在我已连接到sys。
connect sys/knl_test7 as sysdba;
select user from dual;
USER:
----
SYS
现在我已经完成了
drop user u1 cascade;
drop user u1 cascade
*
ERROR at line 1:
ORA-01940: cannot drop a user that is currently connected