MySQL 8.0

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CREATE TABLE IF NOT EXISTS user (
  `id` CHAR(40) CHARACTER SET 'utf8' COLLATE 'utf8_bin' NOT NULL,
  PRIMARY KEY (`id`)
);

CREATE TABLE IF NOT EXISTS `tag` (
  `id` INT(11) NOT NULL AUTO_INCREMENT,
  `name` VARCHAR(255) NULL DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE INDEX `name` (`name` ASC)
);

CREATE TABLE IF NOT EXISTS `bookmark` (
  `id` INT(11) NOT NULL AUTO_INCREMENT,
  `user_id` CHAR(36) CHARACTER SET 'utf8' COLLATE 'utf8_bin' NOT NULL,
  `link_id` INT(11) NOT NULL,
  PRIMARY KEY (`id`),
  INDEX `fk_bookmark_user1_idx` (`user_id` ASC),
  CONSTRAINT `fk_bookmark_user1`
    FOREIGN KEY (`user_id`)
    REFERENCES `user` (`id`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION
);

CREATE TABLE IF NOT EXISTS `bookmark_tag` (
  `bookmark_id` INT(11) NOT NULL,
  `tag_id` INT(11) NOT NULL,
  PRIMARY KEY (`bookmark_id`, `tag_id`),
  INDEX `fk_bookmark_tag_bookmark1_idx` (`bookmark_id` ASC),
  INDEX `fk_bookmark_tag_tag1_idx` (`tag_id` ASC),
  CONSTRAINT `fk_bookmark_tag_bookmark1`
    FOREIGN KEY (`bookmark_id`)
    REFERENCES `bookmark` (`id`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION,
  CONSTRAINT `fk_bookmark_tag_tag1`
    FOREIGN KEY (`tag_id`)
    REFERENCES `tag` (`id`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION
);

INSERT INTO `user` 
  (`id`)
VALUES 
  ('e4e2bb46-c210-4a47-9e84-f45c789fcec1'),
  ('b95274c9-3d26-4ce3-98b2-77dce5bd7aae');

INSERT INTO `tag` 
  (`id`, `name`) 
VALUES 
 (1, 'foo'),
 (2, 'bar'),
 (3, 'baz');

INSERT INTO `bookmark`
  (`id`, `user_id`, `link_id`)
VALUES
  (1, 'e4e2bb46-c210-4a47-9e84-f45c789fcec1', 1),
  (2, 'e4e2bb46-c210-4a47-9e84-f45c789fcec1', 2),
  (3, 'e4e2bb46-c210-4a47-9e84-f45c789fcec1', 3),
  (4, 'b95274c9-3d26-4ce3-98b2-77dce5bd7aae', 4),
  (5, 'b95274c9-3d26-4ce3-98b2-77dce5bd7aae', 5);
  
INSERT INTO `bookmark_tag`
  (`bookmark_id`, `tag_id`)
VALUES
	(1, 1),
	(1, 2),
	(1, 3),
	(2, 1),
	(2, 3),
	(3, 1),
	(3, 3),
	(4, 2),
	(5, 1),
	(5, 2),
	(5, 3);

Records: 2  Duplicates: 0  Warnings: 0

Records: 3  Duplicates: 0  Warnings: 0

Records: 5  Duplicates: 0  Warnings: 0

Records: 11  Duplicates: 0  Warnings: 0

user_id	tags
b95274c9-3d26-4ce3-98b2-77dce5bd7aae	[2, 1, 3]
e4e2bb46-c210-4a47-9e84-f45c789fcec1	[1, 2, 3]