Example of inserting missing service_id into a GTFS

insert.sql

INSERT INTO gtfs.calendar (feed_index, service_id, monday, tuesday, wednesday, thursday, friday, saturday, sunday, start_date, end_date)
SELECT a.feed_index, a.service_id, monday, tuesday, wednesday, thursday, friday, saturday, sunday, start_date, end_date
FROM (
  SELECT feed_index, service_id 
    FROM gtfs.trips a 
      LEFT JOIN gtfs.calendar b using (feed_index, service_id) 
  WHERE COALESCE(b.monday, b.friday) IS NULL 
  GROUP BY feed_index, service_id
  ) a 
  INNER JOIN gtfs.calendar b ON a.feed_index = b.feed_index AND (
      replace(a.service_id, '-BM', '-SDon-BM') = b.service_id OR
      a.service_id || '-SDon' = b.service_id
    );