mysql 错误信息：
ERROR 2002 (HY000): Can‘t connect to local MySQL server through socket ‘/var/run/mysqld/mysqld.sock
出错原因：
可能是你运行了/etc/init.d/mysql start,然后试图登陆sql
mysql -u <username> -p
解决方法：
sudo service mysql restart
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock
原文：http://blog.csdn.net/duomoke/article/details/41963025