1) /etc/init.d/mysqld stop
2) mysqld_safe --skip-grant-tables &
3) mysql -u root
4) Setup new MySQL root user password
use mysql;
#update user set password=PASSWORD("123456") where User=‘root‘;
#update mysql.user set password=PASSWORD("123456") where user=‘root‘;
update mysql.user set authentication_string=password(‘123qwe‘) where user=‘root‘ and Host =‘localhost‘;
flush privileges;
quit
5) Stop MySQL Server: /etc/init.d/mysqld stop
6) Start MySQL server and test it:
/etc/init.d/mysqld start
mysql -u root -p
MYSQL: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
原文：http://www.cnblogs.com/dearxixi/p/6824959.html