s.ไม่จำเป็นที่จะต้องใช้ทุกตาราง
s.It is not neccessary to use all the tables.
 PostTags:  PostId [ number]  TagId [ number] 
WITH QuestionsPerUser AS (SELECT U.Id AS UserId, COUNT(*) AS QuestionCount FROM Users AS u INNER JOIN Posts AS p ON u.Id = p.OwnerUserId WHERE p.PostTypeId = 1 GROUP BY U.Id), UsersWITHMoreThan28Questions AS (SELECT * FROM QuestionsPerUser WHERE QuestionCount > 28) SELECT SUM(QuestionCount) FROM UsersWITHMoreThan28Questions