1、使用oracle用户登录，连接数据库

[oracle@wuzj ~]$ sqlplus /nolog

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

SQL> conn /as sysdba
Connected.

//查看用户
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.

//修改用户口令格式 alter user 用户名 identified by 新密码;

SQL> alter user system identified by manager;

User altered.

//再次查看，对比发现密码已经更换

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

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

28 rows selected.

SQL>

//现在就可以用此密码链接进行操作了

SQL> connect system/manager

已连接。

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另一种修改值的办法

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

用户已更改。

//在试试这个密码

SQL> connect system/oracle

已连接。

//这个密码就不灵了

SQL> connect system/manager

ERROR:

ORA-01017: invalid username/password; logon denied

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sys登陆plsqldev修改用户密码
alter user sjxxtfp identified by abc123 ;
alter user 用户名 identified by 密码 ;