Oracle 10g修改数据库字符集：WE8ISO8859P1=>ZHS16GBK

查看当前字符集

引用
SQL> select * from nls_database_parameters where parameter like '%SET%';

PARAMETER VALUE
------------------------------ ----------------------------------------
NLS_CHARACTERSET WE8ISO8859P1
NLS_NCHAR_CHARACTERSET AL16UTF16

引用
SQL> select userenv('language') from dual;

USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.WE8ISO8859P1

尝试直接修改字符集

引用
SQL> ALTER DATABASE CHARACTER SET ZHS16GBK;
ALTER DATABASE CHARACTER SET ZHS16GBK
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set

采用Oracle内部命令修改字符集（注意：此流程仅用于测试，在Oracle 10g中建议用CSALTER修改！）

引用
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.

Total System Global Area 167772160 bytes
Fixed Size 1218316 bytes
Variable Size 62916852 bytes
Database Buffers 100663296 bytes
Redo Buffers 2973696 bytes
Database mounted.
SQL> ALTER SYSTEM ENABLE RESTRICTED SESSION;

SQL> ALTER SYSTEM ENABLE RESTRICTED SESSION;

System altered.

SQL> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;

System altered.

SQL> ALTER SYSTEM SET AQ_TM_PROCESSES=0;

System altered.

SQL> ALTER DATABASE OPEN;

Database altered.

SQL> ALTER DATABASE CHARACTER SET INTERNAL_USE zhs16gbk;

Database altered.

修改时alert日志显示：

引用
Completed: ALTER DATABASE OPEN
Tue May 18 10:56:43 2010
ALTER DATABASE CHARACTER SET INTERNAL_USE zhs16gbk
Tue May 18 10:56:47 2010
Updating character set in controlfile to ZHS16GBK
Synchronizing connection with database character set information
Refreshing type attributes with new character set information
Completed: ALTER DATABASE CHARACTER SET INTERNAL_USE zhs16gbk

查看修改后结果：

引用
SQL> select * from nls_database_parameters where parameter like '%SET%';

PARAMETER
------------------------------
VALUE
--------------------------------------------------------------------------------
NLS_CHARACTERSET
ZHS16GBK

NLS_NCHAR_CHARACTERSET
AL16UTF16

引用

SQL> select userenv('language') from dual;

USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.ZHS16GBK