首先停止mysql服务：
sudo /etc/init.d/mysql stop
修改mysql的配置文件：
sudo gedit /etc/mysql/my.cnf
找到客户端配置[client] 在下面添加
#默认字符集为utf8 default-character-set=utf8
找到[mysqld] 添加
#默认字符集为utf8 character_set_server=utf8 #default-character-set=utf8 #说明如果这样设置启动会出错，所以用character_set_server=utf8代替default-character-set=utf8
找到[mysql] 添加
#默认字符集为utf8 default-character-set=utf8
重启mysql服务
sudo /etc/init.d/mysql start
进入mysql的命令行
mysql -uusername -puserpassword
查看编码是否改变
mysql> show variables like ‘%char%‘;
出现以下状态：
+--------------------------+----------------------------+
| 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/ |
+--------------------------+----------------------------+
说明编码修改成功！