下面就是解决方案：
1- From the command prompt, stop isqlplus:
c:>isqlplusctl stop
2- Assuming that you install oracle under C drive, run the following comands:
c:>set oracle_home=c:oracleproduct10.2.0db_1
c:>set java_home=%ORACLE_HOME%jdk
3- Change directory to:
cd %ORACLE_HOME%oc4jj2eeisqlplusapplication-deploymentsisqlplus
4- Suppose you need to create a new user with user name 'yoyo' and password 'ch51*****', run the following command:
%JAVA_HOME%binjava -Djava.security.properties=%ORACLE_HOME%oc4jj2eehomeconfigjazn.security.props -jar %ORACLE_HOME%oc4jj2eehomejazn.jar -user "iSQL*Plus DBA/admin" -password welcome -adduser "iSQL*Plus DBA" yoyo ch51*****
5- To check that adding this new user was successful, run the following command:
%JAVA_HOME%binjava -Djava.security.properties=%ORACLE_HOME%oc4jj2eehomeconfigjazn.security.props -jar %ORACLE_HOME%oc4jj2eehomejazn.jar -user "iSQL*Plus DBA/admin" -password welcome -listusers "iSQL*Plus DBA"
结果：
admin
yoyo
6- To grant a user access to the webDba role from the command line, enter:
%JAVA_HOME%binjava -Djava.security.properties=%ORACLE_HOME%oc4jj2eehomeconfigjazn.security.props -jar %ORACLE_HOME%oc4jj2eehomejazn.jar -user "iSQL*Plus DBA/admin" -password welcome -grantrole webDba "iSQL*Plus DBA" yoyo
7- Now, run start isqlplus again and enjoy it:
isqlplusctl start
8. 再次访问： http://hostname:5560/isqlplus/dba, 给出用户名和密码： yoyo 和 ch51***** （全小写），就可看到isqlplus的登入界面，
然后再提供用户名：SYSTEM,口令：ch51*****， 连接标识:(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=KCSQLBI)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=orcl))),权限SYSDBA， 就可以访问了。
【Oracle 10g的DBA无法登录解决方案】相关文章：
★ oracle 11.1.0.7版本也会出现access$表丢失导致数据库无法启动
★ SQL Server、Oracle和MySQL判断NULL的方法