mysqladmin: connect to server at 'localhost' failed error: 'Access denied for user 'root'@'localhost' (using password: YES)'

就当作自己忘记Mysql密码把，忘记密码的解决方法

---

一、mysql登录错误
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: YES)'
无法修改密码
用 service mysqld stop
mysqld_safe --skip-grant-tables &
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
service mysqld restart
mysql -uroot -p新密码进入

===========================================================
二，忘记本地root的登录密码
解决过程：
1、编辑/etc/my.cnf
在[mysqld] 配置部分添加一行
skip-grant-tables

2、保存后重启mysql
[root@localhost etc]# service mysqld restart
Shutting down MySQL. [ OK ]
Starting MySQL. [ OK ]

3、登录数据库重新设置root密码
[root@localhost ~]# mysql -uroot -p mysql
Enter password:
直接回车进入

Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 1
Server version: 5.1.47-log Source distribution
Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)

执行下列语句
mysql> update user set password=password("mysql") where user='root';
Query OK, 4 rows affected (0.00 sec)
Rows matched: 4 Changed: 4 Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

4、删除/etc/my.cnf文件中添加的“skip-grant-tables”行，重启mysql；
用新设的密码就能正常登录了；

=================================================

介绍一个非常有用的mysql启动参数—— --skip-grant-tables。 顾名思义，就是在启动mysql时不启动grant-tables，授权表。有什么用呢？当然是忘记管理员密码后有用。
操作方法：
1、杀掉原来进行着的mysql：
rcmysqld stop
或者：
service mysqld stop
或者：
kill -TERM mysqld
2、以命令行参数启动mysql：
/usr/bin/mysqld_safe --skip-grant-tables &
3、修改管理员密码：
use mysql;
update user set password=password('yournewpasswordhere') where user='root';
flush privileges;
exit;
4、杀死mysql，重启mysql