MySQL出错：ERROR 1045 (28000)的解决方法

MySQL突然不能用了，症状如下：

[root@bogon ok]# mysql
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

[root@bogon ok]# mysql -uroot -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

[root@bogon ok]# /etc/init.d/httpd start
正在启动 httpd：

[root@bogon ok]# /etc/init.d/mysqld restart           
停止 mysqld： [确定]
正在启动 mysqld： [确定]

[root@bogon ok]# mysql
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
[root@bogon ok]# mysql -uroot -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

解决方法：重改密码
[root@bogon ok]# /etc/init.d/mysqld stop
停止 mysqld： [确定]

[root@bogon ok]# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
[1] 10354
[root@bogon ok]# 150404 16:46:14 mysqld_safe Logging to '/var/log/mysqld.log'.
150404 16:46:14 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

[root@bogon ok]# mysql -u root mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
。。。。。。。
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql>

[root@bogon ok]# mysql -u root -p
Enter password:

mysql>

问题解决。