CREATE TABLE `bookmark` (
	`id` int PRIMARY KEY,
	`folder_id` int,
	`name` varchar(255),
	`description` varchar(255),
	`url` varchar(255),
	FOREIGN KEY(`folder_id`) REFERENCES `folder` (`id`)
);
CREATE TABLE `folder` (
	`id` int PRIMARY KEY,
	`name` varchar(255),
	`description` varchar(255)
);
CREATE TABLE `folder_depth` (
	`parent_id` int,
	`child_id` int,
	FOREIGN KEY(`parent_id`) REFERENCES `folder` (`id`),
	FOREIGN KEY(`child_id`) REFERENCES `folder` (`id`)
);