我们在删除数据库用户时候会碰到如下错误
SQL> DROP USER sys_xj cascade;
DROP USER sys_xj cascade
*
ERROR at line 1:
ORA-01940: cannot drop a user that is currently connected
解决方法：
1.查询出还在连接的此用户会话进程
SQL> SELECT SID,SERIAL# FROM V$SESSION WHERE USERNAME=‘SYS_XJ‘
2 ;
SID SERIAL#
---------- ----------
452 8801
474 1523
2.结束此用户所有会话
SQL> ALTER SYSTEM KILL SESSION ‘452,8801‘;
System altered.
SQL> ALTER SYSTEM KILL SESSION ‘474,1523‘;
System altered.
3.删除用户
SQL> DROP USER sys_xj cascade;
User dropped.
此时删除成功
ORA-01940: cannot drop a user that is currently connected解决方法
原文：http://www.cnblogs.com/binfoo/p/4845988.html