-- Ensure L3 "Allergi matlagning" exists under:
-- Mejeri, ost & ägg > Matlagning

INSERT INTO `Category` (`name`, `parentId`)
SELECT 'Allergi matlagning', c2.id
FROM `Category` c1
JOIN `Category` c2
  ON c2.parentId = c1.id
  AND c2.name = 'Matlagning'
LEFT JOIN `Category` c3
  ON c3.parentId = c2.id
  AND c3.name = 'Allergi matlagning'
WHERE c1.name = 'Mejeri, ost & ägg'
  AND c1.parentId IS NULL
  AND c3.id IS NULL;