在虚拟机里安装了MySQL（CentOS6.3 + MySQL5.5.30），grant all privileges on *.* to ‘dev’@’localhost′ identified by '123456' with grant option;结果显示：ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)我确定我输入的root密码是正确的，因为登录时使用了密码登录mysql -u root -p另外，我的user表里没有user为空的记录select user,host from mysql.user+---+------------+| user | host |+---+------------+| dev | % || root | 192.168.242.1 || root | localhost |+---+------------+