mysql 数据库密码忘记

linux下mysql的root密码忘记解决方

1．首先确认服务器出于安全的状态，也就是没有人能够任意地连接MySQL数据库。 因为在重新设置MySQL的root密码的期间，MySQL数据库完全出于没有密码保护的 状态下，其他的用户也可以任意地登录和修改MySQL的信息。可以采用将MySQL对 外的端口封闭，并且停止Apache或者nginx以及所有的用户进程的方法实现服务器的准安全 状态。最安全的状态是到服务器的Console上面操作，并且拔掉网线。

 2．修改MySQL的登录设置： 

# vi /etc/my.cnf 
在[mysqld]的段中加上一句：skip-grant-tables 
例如： 
[mysqld] 
datadir=/var/lib/mysql 
socket=/var/lib/mysql/mysql.sock 
skip-grant-tables 
保存并且退出vi。 

3．重新启动mysqld 
MySQL的启动方式已经加入到了常规启动，步骤此处略去
# /etc/init.d/mysqld restart 
Shutting down MySQL. SUCCESS! 
Starting MySQL.. SUCCESS!
4．登录并修改MySQL的root密码 
mysql 
Welcome to the MySQL monitor. Commands end with ; or \g. 
Your MySQL connection id is 3 to server version: 3.23.56 
Type 'help;' or '\h' for help. Type '\c' to clear the buffer. 
首先切换到mysql库
mysql> USE mysql ;   ###===首先切换到mysql库
Reading table information for completion of table and column names 
You can turn off this feature to get a quicker startup with -A 
Database changed 
利用update命令设置新密码
mysql> UPDATE user SET Password = password ( 'new-password' ) WHERE User = 'root' ; 
Query OK, 0 rows affected (0.00 sec) 
Rows matched: 2 Changed: 0 Warnings: 0 
刷新数据库权限
mysql> flush privileges ; 
Query OK, 0 rows affected (0.01 sec) 
mysql> quit   
Bye 
5．将MySQL的登录设置修改回来 
# vi /etc/my.cnf 
将刚才在[mysqld]的段中加上的skip-grant-tables删除 
保存并且退出vi。 
6．重新启动mysqld 
# /etc/init.d/mysqld restart 
Stopping MySQL: [ OK ] 
Starting MySQL: [ OK ]



验证
[root@MySQL ~]# mysql -uroot -p123456    ###原来的密码不能了
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
[root@MySQL ~]# mysql -uroot -poldboy   ##跳过授权修改的密码可以成功登陆
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.5.32 MySQL Community Server (GPL)
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> Ctrl-C -- exit!
Aborted