mac下mysql的DMG格式安装内有安装文件，却没有卸载文件……很郁闷的事。
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.*