Oracle DataBase 编码格式

sqlplus 查询 Oracle 数据库结果乱码或显示 ? ，则需要设置字符集。

一、客户端字符集

格式：NLS_LANG=language_territory.charset

Language： 指定服务器消息的语言， 影响提示信息是中文还是英文

Territory： 指定服务器的日期和数字格式

Charset：  指定字符集

如：SIMPLIFIED CHINESE_CHINA.ZHS16GBK

Linux 环境

# 查看系统编码
locale

# 临时设置系统编码
# 永久设置(CentOS7)编辑 /etc/locale.conf
export LANG="zh_CN.UTF-8"

# 临时设置 Oracle 客户端字符集，与系统编码一致
export NLS_LANG=american_america.AL32UTF8

Windows 环境

# set 设置临时环境变量，只针对当前 Shell 有效，关闭 Shell 就没有了
# setx 设置永久环境变量，和在我的电脑上右键属性设置是一样的效果

# 管理员方式打开 CMD
# 设置当前用户环境变量
setx NLS_LANG "AMERICAN_AMERICA.UTF8"
# 设置系统环境变量
setx NLS_LANG "AMERICAN_AMERICA.UTF8" /m

二、服务端字符集

常用字符集

ZHS16GBK：存储中国人常用的字符

UTF8：unicode字符集，存储全世界的字符，只是不全

AL32UTF8：unicode字符集，比UTF8大多了，unicode字符集使用它，全但性能较差

以 sys 身份登录进行修改

-- 查看当前字符集
select * from v$nls_parameters where parameter = 'NLS_CHARACTERSET';
SELECT USERENV('language') FROM DUAL;
SELECT parameter, value FROM v$nls_parameters WHERE parameter LIKE '%CHARACTERSET';

-- 关闭 database
shutdown immediate;

-- 以启动数据库到 mount 状态下
startup mount;

-- 设置session
ALTER SESSION SET SQL_TRACE=TRUE;
ALTER SYSTEM ENABLE RESTRICTED SESSION;
ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
ALTER SYSTEM SET AQ_TM_PROCESSES=0;

-- 启动 database
alter database open;

-- 修改字符集
ALTER DATABASE CHARACTER SET AL32UTF8;
-- 强制修改字符集
ALTER DATABASE character set INTERNAL_USE AL32UTF8;

-- 关闭 database
shutdown immediate;

-- 重启
startup;

三、常见的locale ID与字符集名称的对应关系，服务端设置的是Locale  ID，客户端设置的是NLS_LANG

Language	Locale ID	NLS_LANG
English (American)	en_US.UTF-8	AMERICAN_AMERICA.AL32UTF8
English (American)	en_US.ISO-8859-1	AMERICAN_AMERICA.WE8ISO8859P1
English (American)	en_US.ISO-8859-15	AMERICAN_AMERICA.WE8ISO8859P15
English (Australian)	en_AU.UTF-8	ENGLISH_AUSTRALIA.AL32UTF8
English (Australian)	en_AU.ISO-8859-1	ENGLISH_AUSTRALIA.WE8ISO8859P1
English (Australian)	en_AU.ISO-8859-15	ENGLISH_AUSTRALIA.WE8ISO8859P15
English (British)	en_GB.UTF-8	ENGLISH_UNITED KINGDOM.AL32UTF8
English (British)	en_GB.ISO-8859-1	ENGLISH_UNITED KINGDOM.WE8ISO8859P1
English (British)	en_GB.ISO-8859-15	ENGLISH_UNITEDKINGDOM.WE8ISO8859P15
English (Ireland)	en_IE.UTF-8	ENGLISH_IRELAND.AL32UTF8
English (Ireland)	en_IE.ISO-8859-1	ENGLISH_IRELAND.WE8ISO8859P1
English (Ireland)	en_IE.ISO-8859-15	ENGLISH_IRELAND.WE8ISO8859P15
German	de_DE.UTF-8	GERMAN_GERMANY.AL32UTF8
German	de_DE.ISO-8859-1	GERMAN_GERMANY.WE8ISO8859P1
German	de_DE.ISO-8859-15	GERMAN_GERMANY.WE8ISO8859P15
French	fr_FR.UTF-8	FRENCH_FRANCE.AL32UTF8
French	fr_FR.ISO-8859-1	FRENCH_FRANCE.WE8ISO8859P1
French	fr_FR.ISO-8859-15	FRENCH_FRANCE.WE8ISO8859P15
Italian	it_IT.UTF-8	ITALIAN_ITALY.AL32UTF8
Italian	it_IT.ISO-8859-1	ITALIAN_ITALY.WE8ISO8859P1
Italian	it_IT.ISO-8859-15	ITALIAN_ITALY.WE8ISO8859P15
Spanish	es_ES.UTF-8	SPANISH_SPAIN.AL32UTF8
Spanish	es_ES.ISO-8859-1	SPANISH_SPAIN.WE8ISO8859P1
Spanish	es_ES.ISO-8859-15	SPANISH_SPAIN.WE8ISO8859P15
Spanish (Mexico)	es_MX.UTF-8	MEXICAN SPANISH_MEXICO.AL32UTF8
Spanish (Mexico)	es_MX.ISO-8859-1	MEXICAN SPANISH_MEXICO.WE8ISO8859P1
Spanish (Mexico)	es_MX.ISO-8859-15	MEXICANSPANISH_MEXICO.WE8ISO8859P15
Portuguese (Brazilian)	pt_BR.UTF-8	BRAZILIANPORTUGUESE_BRAZIL.AL32UTF8
Portuguese (Brazilian)	pt_BR.ISO-8859-1	BRAZILIANPORTUGUESE_BRAZIL.WE8ISO8859P1
Portuguese (Brazilian)	pt_BR.ISO-8859-15	BRAZILIANPORTUGUESE_BRAZIL.WE8ISO8859P15
Japanese	ja_JP.EUC-JP	JAPANESE_JAPAN.JA16EUC
Japanese	ja_JP.UTF-8	JAPANESE_JAPAN.AL32UTF8
Korean	ko_KR.EUC-KR	KOREAN_KOREA.KO16KSC5601
Korean	ko_KR.UTF-8	KOREAN_KOREA.AL32UTF8
Chinese (simplified)	zh_CN.GB18030	SIMPLIFIEDCHINESE_CHINA.ZHS32GB18030
Chinese (simplified)	zh_CN.UTF-8	SIMPLIFIED CHINESE_CHINA.AL32UTF8
Chinese (traditional)	zh_TW.BIG5	TRADITIONALCHINESE_TAIWAN.ZHT16BIG5
Chinese (traditional)	zh_TW.UTF-8	TRADITIONAL CHINESE_TAIWAN

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https://docs.oracle.com/en/database/oracle/oracle-database/18/ntcli/configuring-locale-and-character-sets-using-nls-lang-environment-variable.html#GUID-100E7F17-656D-49B5-BC06-943A7278479D