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

#1.停止mysql数据库
/etc/init.d/mysqld stop
 
#2.执行如下命令
mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
 
#3.使用root登录mysql数据库
mysql -u root mysql
 
#4.更新root密码
mysql> UPDATE user SET Password=PASSWORD(‘newpassword‘) where USER=‘root‘;
#最新版MySQL请采用如下SQL：
mysql> UPDATE user SET authentication_string=PASSWORD(‘newpassword‘) where USER=‘root‘;
 
#5.刷新权限 
mysql> FLUSH PRIVILEGES;
 
#6.退出mysql
mysql> quit
 
#7.重启mysql
/etc/init.d/mysqld restart
 
#8.使用root用户重新登录mysql
mysql -uroot -p 
Enter password: <输入新设的密码newpassword>