Database 1613. Find the Missing IDs ¶ SQL 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17WITH RECURSIVE Ids AS ( SELECT 1 AS id UNION ALL SELECT id + 1 FROM Ids WHERE id < ( SELECT MAX(customer_id) FROM Customers ) ) SELECT Ids.id AS ids FROM Ids LEFT JOIN Customers ON (Ids.id = Customers.customer_id) WHERE Customers.customer_id IS NULL ORDER BY 1; Was this page helpful? Thanks for your feedback! Thanks for your feedback! Help us improve this page by using our feedback form.