原文：oracle11g更改字符集AL32UTF8爲ZHS16GBK 作者:李高鬆
Sql代碼
Database character set (AL32UTF8) and Client character set (ZHS16GBK) are different.
Character set conversion may cause unexpected results.
Note: you can set the client character set through the NLS_LANG environment variable or the NLS_LANG registry key in
HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_OraDb11g_home1.
SIMPLIFIED CHINESE_CHINA.ZHS16GBK 包含 AMERICAN_AMERICA.AL32UTF8.
-- 這可是個麻煩事，不是改客戶端字符集的問題。要改數據庫的字符集。
SQL> conn /as sysdba
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 ZHS16GBK;
ORA-12712: new character set must be a superset of old character set
--提示我們的字符集：新字符集必須爲舊字符集的超集，這時我們可以跳過超集的檢查做更改：
SQL> ALTER DATABASE character set INTERNAL_USE ZHS16GBK;
--我們看到這個過程和之前ALTER DATABASE CHARACTER SET操作的內部過程是完全相同的，也就是說INTERNAL_USE提供的幫助就是使Oracle數據庫繞過了子集與超集的校驗.
SQL> select * from v$nls_parameters;
SQL> shutdown immediate;
SQL> startup
SQL> select * from v$nls_parameters;
--以後安裝oracle11g的時候記得選擇自定義安裝，把這個字符集的事情事先弄好。