问题描述：登录mysql时突然发现无法登录，密码不正确？但是密码记录的对啊，真是头疼。算了，还是来些管用的办法吧。
报错信息如下：
[root@sam ~]# mysql -u root -p
报错信息如下：
[root@sam ~]# mysql -u root -p
Enter password:********
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
1. 关闭mysql
# /etc/init.d/mysql stop
2. 启动mysql 时带有忽略密码参数
# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
3. 用root用户登录mysql
# mysql -u root mysql
4. 修改root用户密码
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root’;
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root’;
5. 刷新mysql的系统权限相关表
mysql> FLUSH PRIVILEGES;
6. 退出
mysql> quit
7. 重新启动mysql
# /etc/init.d/mysqld restart
8. 用root用户带密码方式登录
[root@sam ~]# mysql -u root -p
[root@sam ~]# mysql -u root -p
Enter password:*********
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.1.73 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>
总结：修改密码的工作是很机密的事情，旁边不要有人啊，哈哈哈。