1、使用oracle用戶登錄，連接數據庫

[oracle@wuzj ~]$ sqlplus /nolog

SQL*Plus: Release 10.2.0.1.0 - Production on Thu Feb 26 12:06:29 2009

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

SQL> conn /as sysdba
Connected.

//查看用戶
SQL> select username,password from dba_users;

USERNAME         PASSWORD
------------------------------ ------------------------------
USER1          BBE7786A584F9103
MGMT_VIEW         4F538DF5F344F348
SYS          8A8F025737A9097A
SYSTEM          970BAA5B81930A40
DBSNMP          FFF45BB2C0C327EC
SYSMAN          2CA614501F09FCCC
OUTLN          4A3BA55E08595C81
MDSYS          72979A94BAD2AF80
ORDSYS          7EFA02EC7EA6B86F
EXFSYS          66F4EF5650C20355
DMSYS          BFBA5A553FD9E28A

USERNAME         PASSWORD
------------------------------ ------------------------------
WMSYS          7C9BA362F8314299
CTXSYS          71E687F036AD56E5
ANONYMOUS         anonymous
XDB          88D8364765FCE6AF
ORDPLUGINS         88A2B2C183431F00
SI_INFORMTN_SCHEMA        84B8CBCA4D477FA3
OLAPSYS          3FB8EF9DB538647C
SCOTT          F894844C34402B67
TSMSYS          3DF26A8B17D0F29F
BI          FA1D2B85B70213F3
PM          72E382A52E89575A

USERNAME         PASSWORD
------------------------------ ------------------------------
MDDATA          DF02A496267DEE66
IX          2BE6F80744E08FEB
SH          9793B3777CD3BD1A
DIP          CE4A36B8E06CA59C
OE          9C30855E7E0CB02D
HR          6399F3B38EDF3288

28 rows selected.

//修改用戶口令 格式 alter user 用戶名 identified by 新密碼;

SQL> alter user system identified by manager;

User altered.

//再次查看，對比發現密碼已經更換

SQL> select username,password from dba_users;

USERNAME         PASSWORD
------------------------------ ------------------------------
USER1          BBE7786A584F9103
MGMT_VIEW         4F538DF5F344F348
SYS          8A8F025737A9097A
SYSTEM          D4DF7931AB130E37
DBSNMP          FFF45BB2C0C327EC
SYSMAN          2CA614501F09FCCC
OUTLN          4A3BA55E08595C81
MDSYS          72979A94BAD2AF80
ORDSYS          7EFA02EC7EA6B86F
EXFSYS          66F4EF5650C20355
DMSYS          BFBA5A553FD9E28A

USERNAME         PASSWORD
------------------------------ ------------------------------
WMSYS          7C9BA362F8314299
CTXSYS          71E687F036AD56E5
ANONYMOUS         anonymous
XDB          88D8364765FCE6AF
ORDPLUGINS         88A2B2C183431F00
SI_INFORMTN_SCHEMA        84B8CBCA4D477FA3
OLAPSYS          3FB8EF9DB538647C
SCOTT          F894844C34402B67
TSMSYS          3DF26A8B17D0F29F
BI          FA1D2B85B70213F3
PM          72E382A52E89575A

USERNAME         PASSWORD
------------------------------ ------------------------------
MDDATA          DF02A496267DEE66
IX          2BE6F80744E08FEB
SH          9793B3777CD3BD1A
DIP          CE4A36B8E06CA59C
OE          9C30855E7E0CB02D
HR          6399F3B38EDF3288

28 rows selected.

SQL>

 //現在就可以用此密碼鏈接進行操作了

SQL> connect system/manager

已連接。

==========================

另一種修改值的辦法

SQL> alter user system identified by values '2D594E86F93B17A1';

用戶已更改。

//在試試這個密碼

SQL> connect system/oracle

已連接。

      //這個密碼就不靈了

SQL> connect system/manager

ERROR:

ORA-01017: invalid username/password; logon denied