用dba登陆
SQL>conn sys/root as sysdba;
SQL> alter user SCOTT account unlock identified by tiger;
User altered.
SQL> select username,account_status from dba_users where username='SCOTT';
USERNAME ACCOUNT_STATUS
------------------------------ --------------------------------
SCOTT OPEN
SQL> conn scott/tiger
Connected.
SQL> select * from tab;
TNAME TABTYPE CLUSTERID
------------------------------ ------- ----------
DEPT TABLE
EMP TABLE
BONUS TABLE
SALGRADE TABLE