Mysql删除用户，为多个主机授予权限

Question

我添加了一个用户到我的mysql-db，并允许从几个主机访问，例如：

GRANT ALL PRIVILEGES ON `db`.* TO 'dbuser'@'host1';
GRANT ALL PRIVILEGES ON `db`.* TO 'dbuser'@'host2';
GRANT ALL PRIVILEGES ON `db`.* TO 'dbuser'@'host3';
GRANT ALL PRIVILEGES ON `db`.* TO 'dbuser'@'host4';
....

完全删除用户的最短方法是什么？我试过了：

drop user 'dbuser'@'%';
ERROR 1396 (HY000): Operation DROP USER failed for 'dbuser'@'%'

drop user 'dbuser';
ERROR 1396 (HY000): Operation DROP USER failed for 'dbuser'@'%'

show grants for 'dbuser';
ERROR 1141 (42000): There is no such grant defined for user 'dbuser' on host '%'

我想，％将被视为通配符。但唯一的方法似乎是每个主机都放弃了用户，例如：

drop user 'dbuser'@'host1';
drop user 'dbuser'@'host2';
drop user 'dbuser'@'host3';
...

是不是有更方便的方法来删除用户？

Answer 1

MySQL <= 5.6.x.

select user,host,password from mysql.user;

MySQL> = 5.7.x.

select user,host,authentication_string from mysql.user;

上面你需要创建一个回滚计划，相信如果你删除很多用户并且想要节省时间，你总是需要一个。

现在回答你的问题：

select concat("DROP USER ","'",user,"'@'",host,"';") from mysql.user where host like "127.0.%" or host like "192.168%";

根据您的平台，探索如何将输出粘贴到文件中并执行它

Answer 2

如果您使用的是MySQL> = 5.0.2，则可以删除帐户及其权限，如下所示：

DROP USER用户;

该语句从所有授权表中删除该帐户的权限行。

（来自：https://dev.mysql.com/doc/refman/5.0/en/drop-user.html）

Answer 3

SELECT GROUP_CONCAT('\'',user, '\'@\'', host, '\'') INTO @users FROM mysql.user WHERE user = 'root';
SET @users = CONCAT('DROP USER ', @users);
PREPARE stmt FROM @users;
EXECUTE stmt;