在虛擬機里安裝了MySQL（CentOS6.3 + MySQL5.5.30），grant all privileges on *.* to ‘dev’@’localhost′ identified by '123456' with grant option;結果顯示：ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)我確定我輸入的root密碼是正確的，因為登錄時使用了密碼登錄mysql -u root -p另外，我的user表里沒有user為空的記錄select user,host from mysql.user+---+------------+| user | host |+---+------------+| dev | % || root | 192.168.242.1 || root | localhost |+---+------------+