MariaDB 10.3

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SELECT VERSION();


VERSION()


10.3.36-MariaDB-1:10.3.36+maria~deb10-log


DROP TABLE IF EXISTS `items`;
DROP PROCEDURE IF EXISTS `sp_test`;
CREATE TABLE IF NOT EXISTS `items` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `item` varchar(255) DEFAULT NULL,
  `count` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`)
);
INSERT INTO `items`
  (`count`, `item`)
VALUES
  ('3', 'item a'),
  ('2', 'item b'),
  ('4', 'item c');

Records: 3  Duplicates: 0  Warnings: 0


CREATE PROCEDURE `sp_test`()
BEGIN
  CREATE TEMPORARY TABLE IF NOT EXISTS `temp_items`
  SELECT `id`, `item`, `count`
  FROM `items`
  LIMIT 0;

  FOR `repeat_row` IN (
    SELECT `id`, `item`, `count`
    FROM `items`
  ) DO
    FOR `current` IN 1..`repeat_row`.`count`
      DO
      INSERT INTO `temp_items`
      SELECT
        `repeat_row`.`id`,
        `repeat_row`.`item`,
        `repeat_row`.`count`;
    END FOR;
  END FOR;

  SELECT `id`, `item`, `count`
  FROM `temp_items`;
  DROP TEMPORARY TABLE IF EXISTS `temp_items`;
END;
CALL `sp_test`;


id
item
count


1
item a
3

1
item a
3

1
item a
3

2
item b
2

2
item b
2

3
item c
4

3
item c
4

3
item c
4

3
item c
4

id	item	count
1	item a	3
1	item a	3
1	item a	3
2	item b	2
2	item b	2
3	item c	4
3	item c	4
3	item c	4
3	item c	4