centOS下mysql-ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

系统centOS-6.3

方法操作很简单，如下：
# /etc/init.d/MySQL stop
# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
# mysql -u root mysql

# mysql>use mysql ;
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root' and host='root' or host='localhost';//把空的用户密码都修改成非空的密码就行了。
mysql> FLUSH PRIVILEGES;
mysql> quit # /etc/init.d/mysqld restart
# mysql -uroot -p
Enter password: <输入新设的密码newpassword>

这样问题就解决了！