mac os   下要卸载MySQL，只需要吧相应的文件删除即可

先切换到root，避免每个删除前都使用sudo

sudo su

rm /usr/local/mysql
rm -rf /usr/local/mysql*
rm -rf /Library/StartupItems/MySQLCOM
rm -rf /Library/PreferencePanes/My*
rm -rf /Library/Receipts/mysql*
rm -rf /Library/Receipts/MySQL*
rm -rf /var/db/receipts/com.mysql.*

vi /etc/hostconfig
删除 MYSQLCOM 定义

另外如果自己定制了MySQL的配置文件，删除/etc/my.cnf