LISTING 3: Query to Find subscription_end

SELECT DISTINCT subscriber_name, magazine_name, subscription_end
FROM magazine_subs m
WHERE NOT EXISTS (SELECT * FROM magazine_subs m2
  WHERE m2.subscriber_name = m.subscriber_name
  AND m2.magazine_name = m.magazine_name
  AND m2.subscription_end > m.subscription_end
  AND m2.subscription_start <= m.subscription_end)