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CREATE TABLE inventory_player ( id int(11) NOT NULL AUTO_INCREMENT, user_id int(11) NOT NULL, item_id int(11) NOT NULL, slot_id int(11) NOT NULL, deleted_at_time datetime DEFAULT NULL, PRIMARY KEY (id) ); INSERT INTO inventory_player VALUES (1, 4, 0, 0, NULL), (2, 4, 0, 1, NULL), (3, 4, 0, 2, NULL), (4, 4, 0, 3, NULL), (5, 4, 1, 4, NULL), (6, 4, 1, 4, NULL), (7, 4, 1, 4, NULL), (8, 4, 1, 4, NULL), (9, 4, 1, 4, NULL); SELECT * FROM inventory_player order by id; SET @ids := null; WITH old as ( SELECT *, DENSE_RANK() OVER (order by item_id DESC) - 1 dr, ROW_NUMBER() OVER (PARTITION BY item_id order by id) rn FROM inventory_player ), jn as ( SELECT o1.id, o1.user_id, o1.item_id, o2.slot_id FROM old o1 INNER JOIN old o2 ON o2.dr = o1.item_id and o1.rn = o2.rn ) UPDATE inventory_player ip INNER JOIN jn ON jn.id = ip.id SET ip.slot_id = jn.slot_id WHERE (SELECT @ids := CONCAT_WS(',', ip.id, @ids)); DELETE FROM inventory_player where id in (@ids); SELECT * FROM inventory_player order by id;