解决drupal 7安装时找不到unix:///var/mysql/mysql.sock 的问题

Warning Error: PDO::__construct(): [2002] No such file or directory (trying to connect via unix:///var/mysql/mysql.sock) in 

解决在Mac下drupal 7安装时找不到unix:///var/mysql/mysql.sock 的问题，用下面的命令就好了
我用的OSX是Mountain Lion

sudo mkdir /var/mysql

sudo ln -s /tmp/mysql.sock /var/mysql/mysql.sock