今天升级了一下Mysql数据库，结果出现了以下错误：
Client does not support authentication protocol requested by server; consider upgrading MySQL client

升级到4.1.7版:
[root@eygle gbook]# mysql -uroot -p -heygle
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 44 to server version: 4.1.7-max

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

查询了一下，在官方网站发现了解决方法:
http://dev.mysql.com/doc/mysql/en/Old_client.html

共有以下两种解决方法:

一:

mysql> SET PASSWORD FOR
-> 'some_user'@'some_host' = OLD_PASSWORD('newpwd');

二:

mysql> UPDATE mysql.user SET Password = OLD_PASSWORD('newpwd')
-> WHERE Host = 'some_host' AND User = 'some_user';
mysql> FLUSH PRIVILEGES;

使用第二种方法，解决了该问题。