当root口令为空时可以进入，改了密码后，再进就提示下面这些: #1251 – Client does not support authentication protocol requested by server; consider upgrading MySQL client 请使用以下两种方法之一 其一: mysql>; SET PASSWORD FOR ->; ‘some_user’@’some_host’ = OLD_PASSWORD(‘newpwd’); 其二: mysql>; UPDATE mysql.user SET Password = OLD_PASSWORD(‘newpwd’) ->; WHERE Host = ‘some_host’ AND User = ‘some_user’; mysql>; FLUSH PRIVILEGES; 官方的解释: MySQL 4.1 and up uses an authentication protocol [...]