1.授权
--授权app用户从指定ip访问数据库的所有权限
grant all privileges on *.* to 'app'@'10.200.12.232' identified by 'app1234';
--取消授权
revoke alter on *.* from 'app'@'10.200.12.232' identified by 'app1234';
--授权app用户从指定ip访问downloaddb数据库的表（增删改查）
grant select,insert,update,delete on downloaddb.* to 'app'@'10.200.12.199' identified by 'app1234' with grant option;
--取消授权
revoke select,insert,update,delete on downloaddb.* from 'app'@'10.200.12.199' identified by 'app1234';
2.刷新权限
--刷新权限
flush privileges;
3,grant all privileges on *.* to 'root'@'%' identified by 'xxxxx';
容许外部所有ip访问