สถิติแท็กต่อวัน #1.ไม่จำเป็นต้องใช้ทุกตาราง
Stats for tags per days #1.It is not neccessary to use all the tables.
 Posts:  Id [ number]  PostTypeId [ number]  AcceptedAnswerId [ number]  ParentId [ number]  CreationDate [ time]  DeletionDate [ time]  Score [ number]  ViewCount [ number]  Body [ text]  OwnerUserId [ number]  OwnerDisplayName [ text]  LastEditorUserId [ number]  LastEditorDisplayName [ text]  LastEditDate [ time]  LastActivityDate [ time]  Title [ text]  Tags [ text]  AnswerCount [ number]  CommentCount [ number]  FavoriteCount [ number]  ClosedDate [ time]  CommunityOwnedDate [ time]  ContentLicense [ text] 
SELECT DATE(CreationDate) AS post_date, Tags, SUM(Score) AS score_sum, SUM(ViewCount) AS views, SUM(AnswerCount) AS answers, SUM(FavoriteCount) AS favorites, SUM(CommentCount) AS comments, COUNT(1) AS usage_cnt FROM Posts WHERE Tags IN ('<r>', '<python>', '<java>', '<scala>', '<ruby>', '<c>', '<c++>', '<c#>', '<spark>', '<hadoop>', '<sql>') AND DATE(CreationDate) BETWEEN '2006-01-01' AND '2017-12-31' AND PostTypeId = 1 GROUP BY DATE(CreationDate), Tags