MYSQL登录错误：mysqladmin: connect to server at 'localhost' failed

mysql登录错误
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: YES)'
并且无法修改密码

输入 mysql -uroot -p 回车进入
>use mysql;
> update user set password=PASSWORD("newpass")where user="root";
 更改密码为 newpassord
> flush privileges; 更新权限
> quit 退出