查看和设置MySQL数据库字符集(转)

查看和设置MySQL数据库字符集作者:scorpio 2008-01-21 10:05:17 标签: 杂谈 Liunx下修改MySQL字符集:1.查找MySQL的cnf文件的位置find / -iname '*.cnf' -print /usr/share/mysql/my-innodb-heavy-4G.cnf
/usr/share/mysql/my-large.cnf
/usr/share/mysql/my-small.cnf
/usr/share/mysql/my-medium.cnf
/usr/share/mysql/my-huge.cnf
/usr/share/texmf/web2c/texmf.cnf
/usr/share/texmf/web2c/mktex.cnf
/usr/share/texmf/web2c/fmtutil.cnf
/usr/share/texmf/tex/xmltex/xmltexfmtutil.cnf
/usr/share/texmf/tex/jadetex/jadefmtutil.cnf
/usr/share/doc/MySQL-server-community-5.1.22/my-innodb-heavy-4G.cnf
/usr/share/doc/MySQL-server-community-5.1.22/my-large.cnf
/usr/share/doc/MySQL-server-community-5.1.22/my-small.cnf
/usr/share/doc/MySQL-server-community-5.1.22/my-medium.cnf
/usr/share/doc/MySQL-server-community-5.1.22/my-huge.cnf

2. 拷贝 small.cnf、my-medium.cnf、my-huge.cnf、my-innodb-heavy-4G.cnf其中的一个到/etc下,命名为my.cnf cp /usr/share/mysql/my-medium.cnf /etc/my.cnf

3. 修改my.cnf

vi /etc/my.cnf

在[client]下添加 default-character-set=utf8

在[mysqld]下添加 default-character-set=utf8

4.重新启动MySQL [root@bogon ~]# /etc/rc.d/init.d/mysql restart Shutting down MySQL                                        [ 确定 ] Starting MySQL.                                            [ 确定 ] [root@bogon ~]# mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 1 Server version: 5.1.22-rc-community-log MySQL Community Edition (GPL)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

5.查看字符集设置

mysql> show variables like 'collation_%'; +----------------------+-----------------+ | Variable_name        | Value           | +----------------------+-----------------+ | collation_connection | utf8_general_ci | | collation_database   | utf8_general_ci | | collation_server     | utf8_general_ci | +----------------------+-----------------+ 3 rows in set (0.02 sec)

mysql> show variables like 'character_set_%'; +--------------------------+----------------------------+ | 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       | /usr/share/mysql/charsets/ | +--------------------------+----------------------------+ 8 rows in set (0.02 sec)

mysql>

其他的一些设置方法: 修改数据库的字符集
   mysql>use mydb   mysql>alter database mydb character set utf-8;

创建数据库指定数据库的字符集   mysql>create database mydb character set utf-8;

通过配置文件修改:

修改/var/lib/mysql/mydb/db.opt default-character-set=latin1 default-collation=latin1_swedish_ci 为 default-character-set=utf8 default-collation=utf8_general_ci

重起MySQL: [root@bogon ~]# /etc/rc.d/init.d/mysql restart

通过MySQL命令行修改:

mysql> set character_set_client=utf8; Query OK, 0 rows affected (0.00 sec)

mysql> set character_set_connection=utf8; Query OK, 0 rows affected (0.00 sec)

mysql> set character_set_database=utf8; Query OK, 0 rows affected (0.00 sec)

mysql> set character_set_results=utf8; Query OK, 0 rows affected (0.00 sec)

mysql> set character_set_server=utf8; Query OK, 0 rows affected (0.00 sec)

mysql> set character_set_system=utf8; Query OK, 0 rows affected (0.01 sec)

mysql> set collation_connection=utf8; Query OK, 0 rows affected (0.01 sec)

mysql> set collation_database=utf8; Query OK, 0 rows affected (0.01 sec)

mysql> set collation_server=utf8; Query OK, 0 rows affected (0.01 sec)

查看: mysql> show variables like 'character_set_%'; +--------------------------+----------------------------+ | 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       | /usr/share/mysql/charsets/ | +--------------------------+----------------------------+ 8 rows in set (0.03 sec)

mysql> show variables like 'collation_%'; +----------------------+-----------------+ | Variable_name        | Value           | +----------------------+-----------------+ | collation_connection | utf8_general_ci | | collation_database   | utf8_general_ci | | collation_server     | utf8_general_ci | +----------------------+-----------------+ 3 rows in set (0.04 sec)

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【知识性文章转载】

MYSQL 字符集问题

MySQL的字符集支持(Character Set Support)有两个方面:

字符集(Character set)和排序方式(Collation)。

对于字符集的支持细化到四个层次:

服务器(server),数据库(database),数据表(table)和连接(connection)。

1.MySQL默认字符集

MySQL对于字符集的指定可以细化到一个数据库,一张表,一列,应该用什么字符集。

但是,传统的程序在创建数据库和数据表时并没有使用那么复杂的配置,它们用的是默认的配置,那么,默认的配置从何而来呢?    (1)编译MySQL 时,指定了一个默认的字符集,这个字符集是 latin1;

(2)安装MySQL 时,可以在配置文件 (my.ini) 中指定一个默认的的字符集,如果没指定,这个值继承自编译时指定的;

(3)启动mysqld 时,可以在命令行参数中指定一个默认的的字符集,如果没指定,这个值继承自配置文件中的配置,此时 character_set_server 被设定为这个默认的字符集;

(4)当创建一个新的数据库时,除非明确指定,这个数据库的字符集被缺省设定为character_set_server;

(5)当选定了一个数据库时,character_set_database 被设定为这个数据库默认的字符集;

(6)在这个数据库里创建一张表时,表默认的字符集被设定为 character_set_database,也就是这个数据库默认的字符集;

(7)当在表内设置一栏时,除非明确指定,否则此栏缺省的字符集就是表默认的字符集;

简单的总结一下,如果什么地方都不修改,那么所有的数据库的所有表的所有栏位的都用 latin1 存储,不过我们如果安装 MySQL,一般都会选择多语言支持,也就是说,安装程序会自动在配置文件中把 default_character_set 设置为 UTF-8,这保证了缺省情况下,所有的数据库的所有表的所有栏位的都用 UTF-8 存储。

2.查看默认字符集(默认情况下,mysql的字符集是latin1(ISO_8859_1)

通常,查看系统的字符集和排序方式的设定可以通过下面的两条命令:

mysql> SHOW VARIABLES LIKE 'character%';

+--------------------------+---------------------------------+

| Variable_name            | Value                           |

+--------------------------+---------------------------------+

| character_set_client     | latin1                          |

| character_set_connection | latin1                          |

| character_set_database   | latin1                          |

| character_set_filesystem | binary                    |

| character_set_results    | latin1                          |

| character_set_server     | latin1                          |

| character_set_system    | utf8                            |

| character_sets_dir       | D:"mysql-5.0.37"share"charsets" |

+--------------------------+---------------------------------+

mysql> SHOW VARIABLES LIKE 'collation_%';

+----------------------+-----------------+

| Variable_name        | Value           |

+----------------------+-----------------+

| collation_connection | utf8_general_ci |

| collation_database   | utf8_general_ci |

| collation_server     | utf8_general_ci |

+----------------------+-----------------+

3.修改默认字符集

(1) 最简单的修改方法,就是修改mysql的my.ini文件中的字符集键值,

如    default-character-set = utf8

character_set_server = utf8

修改完后,重启mysql的服务,service mysql restart

使用 mysql> SHOW VARIABLES LIKE 'character%';查看,发现数据库编码均已改成utf8

+--------------------------+---------------------------------+

| 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       | D:"mysql-5.0.37"share"charsets" |

+--------------------------+---------------------------------+

(2) 还有一种修改字符集的方法,就是使用mysql的命令

mysql> SET character_set_client = utf8 ;

mysql> SET character_set_connection = utf8 ;

mysql> SET character_set_database = utf8 ;

mysql> SET character_set_results = utf8 ;

mysql> SET character_set_server = utf8 ;

mysql> SET collation_connection = utf8 ;

mysql> SET collation_database = utf8 ;

mysql> SET collation_server = utf8 ;

一般就算设置了表的默认字符集为utf8并且通过UTF-8编码发送查询,你会发现存入数据库的仍然是乱码。问题就出在这个connection连接层上。解决方法是在发送查询前执行一下下面这句:

SET NAMES 'utf8';它相当于下面的三句指令:

SET character_set_client = utf8;

SET character_set_results = utf8;

SET character_set_connection = utf8;

总结:

因此,使用什么数据库版本,不管是3.x,还是4.0.x还是4.1.x,其实对我们来说不重要,重要的有二:

1) 正确的设定数据库编码.MySQL4.0以下版本的字符集总是默认ISO8859-1,MySQL4.1在安装的时候会让你选择。如果你准备使用UTF- 8,那么在创建数据库的时候就要指定好UTF-8(创建好以后也可以改,4.1以上版本还可以单独指定表的字符集)

2) 正确的设定数据库connection编码.设置好数据库的编码后,在连接数据库时候,应该指定connection的编码,比如使用jdbc连接时,指定连接为utf8方式.

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