CREATE TABLE `User` (
	`id` int,
	`username` varchar(255),
	`salt` varchar(255),
	`password_digest` varchar(255),
	`is_enabled` bool
);
CREATE TABLE `Role` (
	`id` int PRIMARY KEY,
	`authority` varchar(255)
);
CREATE TABLE `Assignment` (
	`user_id` int,
	`role_id` int,
	FOREIGN KEY(`user_id`) REFERENCES `User` (`id`),
	FOREIGN KEY(`role_id`) REFERENCES `Role` (`id`)
);