更改MySQL字符:

客户端

default-character-set=utf8

mysqld

character_set_server=utf8

我们不应该在mysqld中编写default-character-set=utf8，因为这可能会导致如下错误:

start:任务启动失败

最后:

 +--------------------------+----------------------------+
 | 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/ |
 +--------------------------+----------------------------+

要将默认值设置为UTF-8，您需要将以下内容添加到my.cnf/my.ini

[client]
default-character-set=utf8mb4

[mysql]
default-character-set=utf8mb4


[mysqld]
collation-server = utf8mb4_unicode_520_ci
init-connect='SET NAMES utf8mb4'
character-set-server = utf8mb4

如果您想更改现有数据库的字符集，请告诉我…你的问题没有直接说明，所以我不确定这是否是你想要做的。

编辑:我在原始答案中用utf8mb4替换了utf8，因为utf8只是UTF-8的一个子集。MySQL和MariaDB都调用UTF-8 utf8mb4。

在Xubuntu 12.04下，我简单地添加了

[mysqld]
character_set_server = utf8

到 /etc/mysql/my.cnf

结果是

mysql> show variables like "%character%";show variables like "%collation%";
+--------------------------+----------------------------+
| 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 (0.00 sec)

+----------------------+-----------------+
| Variable_name        | Value           |
+----------------------+-----------------+
| collation_connection | utf8_general_ci |
| collation_database   | utf8_general_ci |
| collation_server     | utf8_general_ci |
+----------------------+-----------------+
3 rows in set (0.00 sec)

也可以看看http://dev.mysql.com/doc/refman/5.6/en/charset-server.html

如果你在使用MySQL Workbench确认客户端的字符集支持时遇到麻烦，那么请记住以下注意事项:

重要的 MySQL Workbench打开的所有连接都会自动设置客户端字符 设置为utf8。手动更改客户端字符集，例如使用set NAMES .．.，可能导致MySQL Workbench不能正确显示字符。为 有关客户端字符集的其他信息，请参见连接字符集 和排序。

因此，我无法用my.cnf更改覆盖MySQL Workbench的字符集。如。设置名称utf8mb4

MySQL 5.5，所有你需要的是:

[mysqld]
character_set_client=utf8
character_set_server=utf8
collation_server=utf8_unicode_ci

Collation_server是可选的。

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       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

在Fedora 21上

$ vi /etc/my.cnf

添加:

[client]
default-character-set=utf8

[mysql]
default-character-set=utf8

[mysqld]
init_connect='SET collation_connection = utf8_unicode_ci'
init_connect='SET NAMES utf8'
character-set-server=utf8
collation-server=utf8_unicode_ci 
skip-character-set-client-handshake

保存并退出。

最后记住，用service mysqld restart重启服务mysqld。