macint0sh

1. 使用SET PASSWORD命令修改    
mysql -u root -p    
mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('newpass');    

2. 使用mysqladmin修改    
mysqladmin -u root password "newpass"    
如果root已经设置过密码，采用如下方法    
mysqladmin -u root password oldpass "newpass"    

3.使用UPDATE修改    
mysql -u root    
mysql> use mysql;    
mysql> UPDATE user SET password = PASSWORD('newpass') WHERE user = 'root';    
mysql> FLUSH PRIVILEGES;    

mysqld_safe --skip-grant-tables &      
mysql -u root mysql      
mysql> UPDATE user SET password=PASSWORD("new password") WHERE user='root';      
mysql> FLUSH PRIVILEGES;