1、字符集对应查看
mysql> show character set; +----------+-----------------------------+---------------------+--------+ | Charset | Description | Default collation | Maxlen | +----------+-----------------------------+---------------------+--------+ | big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 | | dec8 | DEC West European | dec8_swedish_ci | 1 | | cp850 | DOS West European | cp850_general_ci | 1 | | hp8 | HP West European | hp8_english_ci | 1 | | koi8r | KOI8-R Relcom Russian | koi8r_general_ci | 1 | | latin1 | cp1252 West European | latin1_swedish_ci | 1 | | latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 | | swe7 | 7bit Swedish | swe7_swedish_ci | 1 | | ascii | US ASCII | ascii_general_ci | 1 | | ujis | EUC-JP Japanese | ujis_japanese_ci | 3 | | sjis | Shift-JIS Japanese | sjis_japanese_ci | 2 | | hebrew | ISO 8859-8 Hebrew | hebrew_general_ci | 1 | | tis620 | TIS620 Thai | tis620_thai_ci | 1 | | euckr | EUC-KR Korean | euckr_korean_ci | 2 | | koi8u | KOI8-U Ukrainian | koi8u_general_ci | 1 | | gb2312 | GB2312 Simplified Chinese | gb2312_chinese_ci | 2 | | greek | ISO 8859-7 Greek | greek_general_ci | 1 | | cp1250 | Windows Central European | cp1250_general_ci | 1 | | gbk | GBK Simplified Chinese | gbk_chinese_ci | 2 | | latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 | | armscii8 | ARMSCII-8 Armenian | armscii8_general_ci | 1 | | utf8 | UTF-8 Unicode | utf8_general_ci | 3 | | ucs2 | UCS-2 Unicode | ucs2_general_ci | 2 | | cp866 | DOS Russian | cp866_general_ci | 1 | | keybcs2 | DOS Kamenicky Czech-Slovak | keybcs2_general_ci | 1 | | macce | Mac Central European | macce_general_ci | 1 | | macroman | Mac West European | macroman_general_ci | 1 | | cp852 | DOS Central European | cp852_general_ci | 1 | | latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 | | utf8mb4 | UTF-8 Unicode | utf8mb4_general_ci | 4 | | cp1251 | Windows Cyrillic | cp1251_general_ci | 1 | | utf16 | UTF-16 Unicode | utf16_general_ci | 4 | | cp1256 | Windows Arabic | cp1256_general_ci | 1 | | cp1257 | Windows Baltic | cp1257_general_ci | 1 | | utf32 | UTF-32 Unicode | utf32_general_ci | 4 | | binary | Binary pseudo charset | binary | 1 | | geostd8 | GEOSTD8 Georgian | geostd8_general_ci | 1 | | cp932 | SJIS for Windows Japanese | cp932_japanese_ci | 2 | | eucjpms | UJIS for Windows Japanese | eucjpms_japanese_ci | 3 | +----------+-----------------------------+---------------------+--------+ 39 rows in set (0.00 sec)
2.查看字符集变量
mysql> show variables like '%char%'; +--------------------------+-------------------------------------+ | Variable_name | Value | +--------------------------+-------------------------------------+ | character_set_client | utf8 | | character_set_connection | utf8 | | character_set_database | utf8 | | character_set_filesystem | binary | | character_set_results | utf8 | | character_set_server | utf8 | | character_set_system | utf8 | | character_sets_dir | /app55/mysql-5.5.45/share/charsets/ | +--------------------------+-------------------------------------+ 8 rows in set (0.00 sec)
3.乱码原因
客户端字符集 character_set_client character_set_connection character_set_results 数据库字符集： Character_set_server character_set_database character_set_system 这两种字符集不相同导致。
4.解决字符集乱码
1).已经有数据库，但是插入数据时乱码，需要如下
mysql> show create database virtual; +----------+------------------------------------------------------------------+ | Database | Create Database | +----------+------------------------------------------------------------------+ | virtual | CREATE DATABASE `virtual` /*!40100 DEFAULT CHARACTER SET utf8 */ | +----------+------------------------------------------------------------------+ 1 row in set (0.00 sec) mysql> use virtual; Database changed mysql> show create table user; +-------+-----------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+-----------------------------------------------------------------------------------------------------------------------+ | user | CREATE TABLE `user` ( `id` int(11) NOT NULL, `name` varchar(20) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+-----------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)
操作前，先set names库和表的character。
2).没有数据库，那么在建立数据库的时候指定数据库格式。
mysql> create database test default character set gbk collate gbk_chinese_ci; mysql> create table user (id int not null,name varchar(20)); mysql> show create table user; +-------+----------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+----------------------------------------------------------------------------------------------------------------------+ | user | CREATE TABLE `user` ( `id` int(11) NOT NULL, `name` varchar(20) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=gbk | 默认继承数据库的字符集 +-------+----------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) 然后， set names ‘gbk’, 再次操作。
3).直接导入sql文件，怎么解决乱码
3.1 sql文件中，加上set names utf8 3.2 mysql>set names utf8; mysql>source file.sql 3.3 mysql命令使用--default-character-set=utf8 导入sql文件 Mysql –uadmin –p’jidian123’ –S /mydata/mysql.sock –default-character-set=utf8
5.set names ‘utf8’ 和—default-character-set=utf8具体干了些什么？
它们都干了相同的事，把下面3个变量的值变成和要操作的数据库字符集相同了。 character_set_client | utf8 | character_set_connection | utf8 | | character_set_results | utf8
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6、结论
字符集乱码问题受4个东西影响。
1）客户端字符集,3个字符集受Linux系统字符集影响。
character_set_client character_set_connection character_set_results
2）要操作的数据库的字符集
Show create database test;
3）要操作的数据表的字符集
Use test; Show create table user
7．更改配置文件
客户端字符集,编辑my.cnf
vi /etc/my.cnf [client] default-character-set = utf8 <===set names 'utf8' 注意：客户端修改字符集不需要重启服务器
服务端字符集，编辑my.cnf
vi /etc/my.cnf [mysqld] default-character-set = utf8 mysql5.1 character-set-server = utf8 mysql5.5 注意：服务端修改字符集需要重启服务器
8大结论：
1）linux服务器字符集
CentOS6 系列 vi /etc/sysconfig/i18n LANG="en_CN.UTF-8" CentOS7 系列 vi /etc/locale.conf LANG="en_CN.UTF-8"
2）linux客户端字符集
secureCRT 工具
3）MySQL服务器字符集配置
永久生效
vi /etc/my.cnf
[mysqld] default-character-set=utf8 mysql5.1 版本 character-set-server=utf8 mysql5.5 版本 重启服务器 提示： 更改后变化的变量 mysql> show variables like 'char%'; +--------------------------+-------------------------------------+ | Variable_name | Value | +--------------------------+-------------------------------------+ | character_set_client | utf8 | | character_set_connection | utf8 | | character_set_database | utf8 | | character_set_filesystem | binary | | character_set_results | utf8 | | character_set_server | utf8 | | character_set_system | utf8 | | character_sets_dir | /app55/mysql-5.5.45/share/charsets/
4）MySQL客户端字符集配置
临时生效：
1、set names 'utf8' 2、mysql -uadmin -p -S /mydata/mysql.sock --default-character-set=utf8
提示：
更改后受影响的变量
mysql> show variables like 'char%'; +--------------------------+-------------------------------------+ | Variable_name | Value | +--------------------------+-------------------------------------+ | character_set_client | utf8 | | character_set_connection | utf8 | | character_set_database | utf8 | | character_set_filesystem | binary | | character_set_results | utf8 | | character_set_server | utf8 | | character_set_system | utf8 | | character_sets_dir | /app55/mysql-5.5.45/share/charsets/
永久生效
vi /etc/my.cnf [client] default-character-set = utf8
提示：
不需要重启服务器，数据证明一切。 并且客户端字符集不会再受linux字符集的影响了。
9.生成环境更改字符集
对已有数据的数据库进行字符集转变，没有没有作用。只能导出数据，重新建库建表。
改库： alter database character set 'ut8'; 改表： alter table character set 'utf8';
生产环境更改字符集方法：latin1 utf8
1）导出表结构
mysqldump -uadmin -p'jidian123' -S /mydata/mysql.sock -d virtual >virtual_bak.sql sed -i 's/latin1/utf8/g' virtual_bak.sql
2.建库
create database virtual default character set utf8 collate utf8_general_ci;
3.更改MySQL默认字符集
[client] default-character-set = utf8 [mysqld] character-set-server = utf8 mysql5.5 配置 default-character-set = utf8 mysql5.1 配置
重启数据库
4.导入数据
mysql -uadmin -p'jidian123' -S /mydata/mysql.sock virtual < virtual_bak.sql
