text: CREATE TABLE `item_value` (
    `id` bigint NOT NULL AUTO_INCREMENT,
    PRIMARY KEY (`id`)
  );
  
  CREATE TABLE `item` (
    `id` bigint NOT NULL AUTO_INCREMENT,
    `attribute_id` bigint DEFAULT NULL,
    `item_value_id` bigint DEFAULT NULL,
    PRIMARY KEY (`id`),
    KEY `FKin1owya2tfds8i1jqyfec6fql` (`attribute_id`),
    KEY `FKnlhb9f2jb6mg57jqym2loobod` (`item_value_id`),
    CONSTRAINT `FKin1owya2tfds8i1jqyfec6fql` FOREIGN KEY (`attribute_id`) REFERENCES `attribute` (`id`),
    CONSTRAINT `FKnlhb9f2jb6mg57jqym2loobod` FOREIGN KEY (`item_value_id`) REFERENCES `item_value` (`id`)
  );
  
  CREATE TABLE `boolean_item_value` (
    `value` bit(1) DEFAULT NULL,
    `id` bigint NOT NULL,
    PRIMARY KEY (`id`),
    CONSTRAINT `FKcwpb9wg6cs96mtd7t1kkwyeiy` FOREIGN KEY (`id`) REFERENCES `item_value` (`id`)
  );
  
  CREATE TABLE `integer_item_value` (
    `value` int DEFAULT NULL,
    `id` bigint NOT NULL,
    PRIMARY KEY (`id`),
    CONSTRAINT `FKerrst1a7a3ck2fwx4pjfl9qef` FOREIGN KEY (`id`) REFERENCES `item_value` (`id`)
  );
  
  CREATE TABLE `double_item_value` (
    `value` double DEFAULT NULL,
    `id` bigint NOT NULL,
    PRIMARY KEY (`id`),
    CONSTRAINT `FK3uiby6j6fg1ju5qjuv4nsp8h8` FOREIGN KEY (`id`) REFERENCES `item_value` (`id`)
  );
  
  CREATE TABLE `textual_item_value` (
    `value` varchar(255) DEFAULT NULL,
    `id` bigint NOT NULL,
    PRIMARY KEY (`id`),
    CONSTRAINT `FKgmw4lgv1fo4wmuns0nr41kmqq` FOREIGN KEY (`id`) REFERENCES `item_value` (`id`)
  );
  
  CREATE TABLE `date_time_item_value` (
    `value` datetime(6) DEFAULT NULL,
    `id` bigint NOT NULL,
    PRIMARY KEY (`id`),
    CONSTRAINT `FK6d7x7lygy1t93jj14sb0wcsg6` FOREIGN KEY (`id`) REFERENCES `item_value` (`id`)
  );