Вземете данни от две таблици, за да направите календар на събития

АКТУАЛИЗИРАНО

SELECT user_id,
       COALESCE(MIN(CASE WHEN  1 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `1`,
       COALESCE(MIN(CASE WHEN  2 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `2`,
       COALESCE(MIN(CASE WHEN  3 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `3`,
       COALESCE(MIN(CASE WHEN  4 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `4`,
       COALESCE(MIN(CASE WHEN  5 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `5`,
       COALESCE(MIN(CASE WHEN  6 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `6`,
       COALESCE(MIN(CASE WHEN  7 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `7`,
       COALESCE(MIN(CASE WHEN  8 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `8`,
       COALESCE(MIN(CASE WHEN  9 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `9`,
       COALESCE(MIN(CASE WHEN 10 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `10`,
       COALESCE(MIN(CASE WHEN 11 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `11`,
       COALESCE(MIN(CASE WHEN 12 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `12`,
       COALESCE(MIN(CASE WHEN 13 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `13`,
       COALESCE(MIN(CASE WHEN 14 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `14`,
       COALESCE(MIN(CASE WHEN 15 BETWEEN DAY(start_date) AND DAY(end_date) THEN event_id END), 0) `15`
  FROM 
(
  SELECT id, event_id,
         CASE WHEN start_date < '2013-03-01' THEN '2013-03-01' ELSE start_date END start_date,
         CASE WHEN end_date   > '2013-03-31' THEN '2013-03-31' ELSE   end_date END end_date,
         user_id
    FROM events
   WHERE (start_date >= '2013-03-01' AND end_date <= '2013-03-31')
      OR (start_date <  '2013-03-01' AND end_date  > '2013-03-31')
      OR (start_date  < '2013-03-01' AND end_date BETWEEN '2013-03-01' AND '2013-03-31')
      OR (start_date BETWEEN '2013-03-01' AND '2013-03-31' AND end_date > '2013-03-31') 
) q
 GROUP BY user_id
 

Изход:

Ето SQLPiddle демонстрация