จำนวนผู้ใช้ตอบอย่างน้อยหนึ่งโพสต์ ไม่จำเป็นต้องใช้ตารางทั้งหมด
Number of users answered at least one post.It is not neccessary to use all the tables.
 TagSynonyms:  Id [ number]  SourceTagName [ text]  TargetTagName [ text]  CreationDate [ time]  OwnerUserId [ number]  AutoRenameCount [ number]  LastAutoRename [ time]  Score [ number]  ApprovedByUserId [ number]  ApprovalDate [ time] 
SELECT COUNT(Posts.Id) AS Answers FROM Posts INNER JOIN Users ON Users.Id = OwnerUserId GROUP BY Posts.PostTypeId