PostId และ # ของผู้เข้าร่วม - สัปดาห์ที่ 2 ของเดือนพฤษภาคม 2554 ไม่จำเป็นต้องใช้ตารางทั้งหมด
PostId and # of Participants - 2week of May 2011.It is not neccessary to use all the tables.
 PostTags:  PostId [ number]  TagId [ number] 
SELECT Id, UserId, COUNT(1) AS cnt FROM (SELECT q.Id, q.OwnerUserId AS userid FROM Posts AS q UNION ALL SELECT q.Id, a.OwnerUserId AS userid FROM Posts AS q LEFT JOIN Posts AS a ON (q.Id = a.ParentId) UNION ALL SELECT q.Id, qc.UserId AS userid FROM Posts AS q LEFT JOIN Posts AS a ON (q.Id = a.ParentId) LEFT JOIN Comments AS qc ON (q.Id = qc.PostId) UNION ALL SELECT q.Id, ac.UserId AS userid FROM Posts AS q LEFT JOIN Posts AS a ON (q.Id = a.ParentId) LEFT JOIN Comments AS ac ON (a.Id = ac.PostId)) AS A WHERE NOT A.UserId IS NULL AND A.Id IN (SELECT Id FROM Posts WHERE PostTypeId = '1' AND CAST(TIME_TO_STR(CreationDate, '%Y%m%d') AS TEXT(8)) = '20110508') GROUP BY A.Id, A.UserId ORDER BY A.Id, A.UserId