本文适用于mysql5.5 mysql5.6 其他版本未测试
mysql -u帐号 -p密码 登录mysql
mysql>SHOW VARIABLES LIKE 'character%'; 查看当前字符集编码方式
MySQL [(none)]> SHOW VARIABLES LIKE 'character%';
+--------------------------+----------------------------------+
| Variable_name | Value |
+--------------------------+----------------------------------+
| character_set_client | latin1 |
| character_set_connection | latin1 |
| character_set_database | gbk |
| character_set_filesystem | binary |
| character_set_results | latin1 |
| character_set_server | gbk |
| character_set_system | utf8 |
| character_sets_dir | /usr/local/mysql/share/charsets/ |
+--------------------------+----------------------------------+
8 rows in set (0.01 sec)
我这里是gbk，现在改成utf8，反之同理
编辑/etc/my.cnf文件
在[client]字段下增加default-character-set = utf8
在[mysqld]字段下增加character-set-server = utf8
在[mysql]字段下增加default-character-set = utf8
注：在mysql字段增加这段后，发现mysql重启报错，于是把这段去掉，mysql就正常了，但是后来我又继续尝试了次，就没有报错，不知道什么问题。
修改完成后需要重启mysql服务！
然后在#mysql -u帐号 -p密码 登录mysql
mysql>SHOW VARIABLES LIKE 'character%';
MySQL [(none)]> SHOW VARIABLES LIKE 'character%';
+--------------------------+----------------------------------+
| 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/local/mysql/share/charsets/ |
+--------------------------+----------------------------------+
8 rows in set (0.01 sec)
此时数据库编码改成utf8