mysql ERROR 1045 (28000): Access denied for user '

# mysql -uroot -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

使用网上介绍的方法修改root用户的密码：
# mysqladmin -uroot -p password 'newpassword'
Enter password:
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: YES)'

现在终于被我找到了解决方法：

切换到root用户，然后进入mysql 的bin目录后，
root@cps-desktop:/usr/local/mysql/bin# /etc/init.d/mysql stop 
root@cps-desktop:/usr/local/mysql/bin# ./mysqld_safe --user=mysql --skip-grant-tables --skip-networking & 
root@cps-desktop:/usr/local/mysql/bin# ./mysql -u root mysql 
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';
mysql> FLUSH PRIVILEGES;
mysql> quit;

最后重启数据库：
root@cps-desktop:/usr/local/mysql/bin# /etc/init.d/mysql restart 
root@cps-desktop:/usr/local/mysql/bin# mysql -u root -p 
Enter password: <输入新设的密码newpassword>

mysql>