create user guest_test@localhost identified by "root";
-- 创建名为guest_test的用户

-- 给guest_test用户赋予guest_test增删改的权限。第一个guest_test指数据库，第二个指用户名，hostname指指定ip

grant create,alter,drop on guest_test.* to guest_test@localhost

-- 给guest_test用户赋予guest_test库中所有表的全部权限
grant all privileges on *.* to guest_test@localhost

-- 给guest_test用户赋予guest_test库中所有表的查询权限
grant select on database.* to guest_test@localhost

-- 给guest_test用户赋予guest_test某个表的用户权限
grant select on guest_test.t1table to guest_test@localhost

revoke select,update,delete,insert on guest_test.* from guest_test@localhost;
flush privileges;

drop user guest_test@localhost

SELECT * FROM mysql.user;