资料来源：http://www.cnblogs.com/TsengYuen/archive/2011/12/06/2278574.html
1 sudo rm /usr/local/mysql
2 sudo rm -rf /usr/local/mysql*
3 sudo rm -rf /Library/StartupItems/MySQLCOM
4 sudo rm -rf /Library/PreferencePanes/My*
5 vim /etc/hostconfig  (and removed the line MYSQLCOM=-YES-)
6 rm -rf ~/Library/PreferencePanes/My*
7 sudo rm -rf /Library/Receipts/mysql*
8 sudo rm -rf /Library/Receipts/MySQL*
9 sudo rm -rf /var/db/receipts/com.mysql.*


卸载mysql后需要重启电脑，否则后续的一些安装操作将会出现错误。

Mac下MySQL卸载方法