Oracle 修改字符集（AL32UTF8 转换成UTF8字符集）

1.首先检查环境

[oracle@vm10-84-32-2 ~]$ sqlplus  / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Thu Jun 11 19:53:38 2020

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> spool 2017_12_08.txt

SQL> set line 4000

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

USERENV('LANGUAGE')
--------------------------------------------------------------------------------------------------------
AMERICAN_AMERICA.AL32UTF8

SQL> select * from v$nls_parameters;

PARAMETER VALUE
-------------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------------
NLS_LANGUAGE AMERICAN
NLS_TERRITORY AMERICA
NLS_CURRENCY $
NLS_ISO_CURRENCY AMERICA
NLS_NUMERIC_CHARACTERS .,
NLS_CALENDAR GREGORIAN
NLS_DATE_FORMAT DD-MON-RR
NLS_DATE_LANGUAGE AMERICAN
NLS_CHARACTERSET AL32UTF8
NLS_SORT BINARY
NLS_TIME_FORMAT HH.MI.SSXFF AM

PARAMETER VALUE
-------------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------------
NLS_TIMESTAMP_FORMAT DD-MON-RR HH.MI.SSXFF AM
NLS_TIME_TZ_FORMAT HH.MI.SSXFF AM TZR
NLS_TIMESTAMP_TZ_FORMAT DD-MON-RR HH.MI.SSXFF AM TZR
NLS_DUAL_CURRENCY $
NLS_NCHAR_CHARACTERSET AL16UTF16
NLS_COMP BINARY
NLS_LENGTH_SEMANTICS BYTE
NLS_NCHAR_CONV_EXCP FALSE

19 rows selected.

SQL>

执行下面命令修改

SQL> shutdown immediate

数据库已经关闭。
已经卸载数据库。
ORACLE 例程已经关闭。
SQL> startup mount
ORACLE 例程已经启动。

Total System Global Area 3373858816 bytes
Fixed Size 2180424 bytes
Variable Size 1946159800 bytes
Database Buffers 1409286144 bytes
Redo Buffers 16232448 bytes
数据库装载完毕。
SQL> alter system enable restricted session;

系统已更改。

SQL> alter system set job_queue_processes=0;

系统已更改。

SQL> alter system set aq_tm_processes=0;

系统已更改。

SQL> alter database open;

数据库已更改。

执行转换命令

SQL> alter database character set  utf8;
alter database character set  utf8
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set


SQL> alter database character set internal_use utf8;

Database altered.

SQL> alter database character set internal_convert utf8;

Database altered.

SQL> alter database character set internal_use utf8;

Database altered.

上面就是执行的时候容易遇到的问题，

SQL> alter database character set  utf8;

Database altered.

SQL> shutdown immediate
数据库已经关闭。
已经卸载数据库。
ORACLE 例程已经关闭。
SQL> startup
ORACLE 例程已经启动。

Total System Global Area 3373858816 bytes
Fixed Size                  2180424 bytes
Variable Size            1946159800 bytes
Database Buffers         1409286144 bytes
Redo Buffers               16232448 bytes
数据库装载完毕。
数据库已经打开。

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

USERENV('LANGUAGE')
--------------------------------------------------------------------------------------------------------
AMERICAN_AMERICA.UTF8

如何将Oracle的字符集由AMERICAN_AMERICA.AL32UTF8修改为SIMPLIFIED CHINESE_CHINA.AL32UTF8

参考：

版权声明：本文为CSDN博主「长林攻城狮」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/shao_yc/article/details/104524240

一直以为将Oracle的AMERICAN_AMERICA.AL32UTF8修改为SIMPLIFIED CHINESE_CHINA.AL32UTF8是Oracle客户端的事情，其实搞错了，我们该做的应该是去修改服务器端的环境变量的语言。

查看当前登录用户环境变量的语言

select userenv('language') from dual;

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

USERENV('LANGUAGE')
--------------------------------------------------------------------------------------------------------
AMERICAN_AMERICA.UTF8

SQL> exit

退出Oracle客户端，修改环境变量

vi .bash_profile

[oracle@vm10-84-32-2 ~]$ whoami
oracle
[oracle@vm10-84-32-2 ~]$ vi .bash_profile
添加以下语句

#export NLS_LANG=AMERICAN_AMERICA.ZHS16GBK
export NLS_LANG="SIMPLIFIED CHINESE_CHINA".AL32UTF8

输入命令使配置生效

source .bash_profile

重新登录Oracle客户端查看

select userenv('language') from dual;

[oracle@vm10-84-32-2 ~]$ sqlplus / as sysdba 

SQL*Plus: Release 11.2.0.4.0 Production on 星期四 6月 11 20:24:54 2020

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

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

USERENV('LANGUAGE')
--------------------------------------------------------------------------------
SIMPLIFIED CHINESE_CHINA.UTF8

SQL> 

需要补充说明的是：

UTF8和AL32UTF8为不同的字符集，在oracle的11.2版本中，UTF8已经不是推荐的一员了。详细说明可查看：https://blog.csdn.net/shao_yc/article/details/104524846

参考：

https://blog.csdn.net/shiyu1157758655/article/details/78748283

https://blog.csdn.net/u010457406/article/details/75646547