修改数据库字符集

修改数据库字符集为：UTF8
查看服务器端字符集
SQL > select * from V$NLS_PARAMETERS
修改：
$sqlplus /nolog
SQL>conn / as sysdba;
若此时数据库服务器已启动，则先执行 SHUTDOWN IMMEDIATE 命
令关闭数据库服务器，然后执行以下命令:
SQL>shutdown immediate;
SQL>STARTUP MOUNT;
SQL>ALTER SYSTEM ENABLE RESTRICTED SESSION;
SQL>ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
SQL>ALTER SYSTEM SET AQ_TM_PROCESSES=0;
SQL>ALTER DATABASE OPEN;
SQL>ALTER DATABASE CHARACTER SET UTF8;
*
ERROR at line 1:
ORA-12721: operation cannot execute when other sessions are active
若出现上面的错误，使用下面的办法进行修改，使用INTERNAL_USE可以跳过超集的检查：
SQL>ALTER DATABASE CHARACTER SET INTERNAL_USE UTF8;
SQL>SHUTDOWN IMMEDIATE;
SQL>STARTUP