查看系统环境变量

[root@bogon ~]# su - oracle
[root@oracle ~]$ echo $LANG
en_US.UTF-8

注意NLS_LANG和系统LANG的编码需要一致

[root@oracle ~]$ vi .bash_profile
# 常用unicode字符集  
export NLS_LANG=AMERICAN_AMERICA.ZHS16GBK
export NLS_LANG=AMERICAN_AMERICA.UTF8
export NLS_LANG=AMERICAN_AMERICA.AL32UTF8

# 常用中文字符集
export NLS_LANG="SIMPLIFIED CHINESE_CHINA.ZHS16GBK"
export NLS_LANG="SIMPLIFIED CHINESE_CHINA.AL32UTF8"
[oracle@bogon ~]$ echo $NLS_LANG
SIMPLIFIED CHINESE_CHINA.AL32UTF8

重启系统

[oracle@bogon ~]# reboot

查询编码语句

> select * from NLS_DATABASE_PARAMETERS;
> SELECT parameter, value FROM v$nls_parameters WHERE parameter LIKE '%CHARACTERSET';
> select userenv('language') from dual;