方法一：?
# /etc/init.d/mysql stop?
# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &?
# mysql -u root mysql?
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';?

mysql> FLUSH PRIVILEGES;?
mysql> quit?
# /etc/init.d/mysql restart?
# mysql -uroot -p?
Enter password: <输入新设的密码newpassword>?
mysql>?grant?all?on?*.*?to?root@'%'?identified?by?'密码'; ?
方法二：?
直接使用/etc/mysql/debian.cnf文件中[client]节提供的用户名和密码:?
# mysql -udebian-sys-maint -p?
Enter password: <输入[client]节的密码>?
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';?
mysql> FLUSH PRIVILEGES;?
mysql> quit?
# mysql -uroot -p?
Enter password: <输入新设的密码newpassword>?