CREATE TABLE `User` (
	`name` varchar(255),
	`id` int PRIMARY KEY
);
CREATE TABLE `Class` (
	`id` int PRIMARY KEY
);
CREATE TABLE `UserClassMapping` (
	`userid` int,
	`classid` int,
	FOREIGN KEY(`userid`) REFERENCES `User` (`id`),
	FOREIGN KEY(`classid`) REFERENCES `Class` (`id`)
);