1、在终端中输入
sudo su
mysqld_safe --skip-grant-tables --skip-networking &这时便能越过权限表，直接登陆MySQL了。
2、新建一个终端，输入
PATH="$PATH":/usr/local/mysql/bin
mysql -u root -p。。。卸载mysql命令。。。
sudo rm /usr/local/mysql
sudo rm -rf /usr/local/mysql*
sudo rm -rf /Library/StartupItems/MySQLCOM
sudo rm -rf /Library/PreferencePanes/My*
vim /etc/hostconfig (and removed the line MYSQLCOM=-YES-)
rm -rf ~/Library/PreferencePanes/My*
sudo rm -rf /Library/Receipts/mysql*
sudo rm -rf /Library/Receipts/MySQL*
sudo rm -rf /var/db/receipts/com.mysql.*