Oracle某个数据文件损坏，如何打开数据库

create tablespace test datafile
            'c:test.ora' size 5M
            AUTOEXTEND ON NEXT 1M MAXSIZE UNLIMITED
            default storage (initial 128K next 1M pctincrease 0)

net stop "OracleWebAssistant0"
            net stop "OracleOraHome81TNSListener"
            net stop "OracleServiceORADB"
            shutdown

net start "OracleWebAssistant0"
            net start "OracleOraHome81TNSListener"
            net start "OracleServiceORADB"

C:>svrmgrl
            svrmgrl>connect internal
            svrmgrl>shutdown
            svrmgrl>startup mount

svrmgrl>alter database datafile 'C:TEST.ORA' offline;

svrmgrl>alter database datafile 'C:TEST.ORA' offline drop;
            svrmgrl>alter database open;

SQL> select file#,name,status from v$datafile;
            SQL> drop tablespace test;