คะแนนเฉลี่ยของคำถามค่าหัว ไม่จำเป็นต้องใช้ตารางทั้งหมด
Average Score of Bounty Questions.It is not neccessary to use all the tables.
 Comments:  Id [ number]  PostId [ number]  Score [ number]  Text [ text]  CreationDate [ time]  UserDisplayName [ text]  UserId [ number]  ContentLicense [ text] 
SELECT AVG(q.Score * 1.0) FROM Votes AS v INNER JOIN Posts AS q ON q.Id = v.PostId WHERE VoteTypeId = 8 AND q.CreationDate >= '2009-01-27' AND q.CreationDate < '2009-11-08'