แจกแจงกิจกรรมรายเดือนตามปีที่ลงทะเบียน ไม่จำเป็นต้องใช้ทุกตาราง
Monthly activity distribution by year of registration.It is not neccessary to use all the tables.
 PostTags:  PostId [ number]  TagId [ number] 
WITH Raw AS (SELECT TIME_TO_STR(Users.CreationDate, '%Y') AS UserYear, DATEFROMPARTS(TIME_TO_STR(Posts.CreationDate, '%Y'), TIME_TO_STR(Posts.CreationDate, '%-M'), 1) AS PostMonth, COUNT(*) AS Count FROM Posts, Users WHERE Posts.OwnerUserId = Users.Id AND Posts.OwnerUserId > 0 GROUP BY TIME_TO_STR(Users.CreationDate, '%Y'), DATEFROMPARTS(TIME_TO_STR(Posts.CreationDate, '%Y'), TIME_TO_STR(Posts.CreationDate, '%-M'), 1)), RawSum AS (SELECT PostMonth, SUM(Count) AS Count FROM Raw GROUP BY PostMonth) SELECT Raw.PostMonth, CAST(Raw.UserYear AS TEXT) AS UserYear, 100.0 * Raw.Count / RawSum.Count AS Pct FROM Raw, RawSum WHERE Raw.PostMonth = RawSum.PostMonth ORDER BY PostMonth, UserYear