最近有个故障整改，需要限制IP访问MySQL数据库，查了一下资料。 做做笔记，多多指教  ``` select Host,User from mysql.user; SELECT DISTINCT CONCAT('User: ''',user,'''@''',host,''';') AS query FROM mysql.user; ``` 查看root用户可以在哪台机器登录 ``` select user,host from mysql.user where user='root'; ``` 修改mysql库里边的user表，限制root用户只能从哪个ip登录 ``` update mysql.user set host='localhost' where user='root'; ``` 刷新权限 ``` flush privileges; ``` ``` mysql>grant select,insert,update,create on test.* to test@'192.168.8.%' identified by '123456'; mysql>grant select,insert,update,create on test.* to test@'192.168.9.%' identified by '123456'; mysql>grant select,insert,update,create on test.* to test@'192.168.20.%' identified by '123456'; ``` 上面的语句表示将test数据库的所有权限授权给test这个用户，只允许test用户在192.168.8/9/20这三个网段的IP范围进行远程登陆，并设置test用户的密码为123456 刷新权限表使其设置生效: mysql> flush privileges; 发现rename也可以用 ``` rename user test@'%' to test@'172.22.137.%'; ```