คะแนนตามอายุบัญชีเป็นเดือน ไม่จำเป็นต้องใช้ตารางทั้งหมด
score by account age in months.It is not neccessary to use all the tables.
 Votes:  Id [ number]  PostId [ number]  VoteTypeId [ number]  UserId [ number]  CreationDate [ time]  BountyAmount [ number] 
SELECT DATEDIFF(MONTH, u.CreationDate, CreationDate) AS "Account age (months)", AVG(CAST(p.Score AS FLOAT)) AS "Average score", DATEDIFF(YEAR, p.CreationDate, GETDATE()) FROM Posts AS p INNER JOIN Users AS u ON p.OwnerUserId = u.Id WHERE p.PostTypeId = 1 AND DATEDIFF(MONTH, u.CreationDate, CreationDate) >= 0 GROUP BY DATEDIFF(MONTH, u.CreationDate, CreationDate), DATEDIFF(YEAR, p.CreationDate, GETDATE()) ORDER BY DATEDIFF(MONTH, u.CreationDate, CreationDate), DATEDIFF(YEAR, p.CreationDate, GETDATE())