แบบสอบถามแนวโน้มเทคโนโลยีในแต่ละปี ไม่จำเป็นต้องใช้ทุกตาราง
query tech trend by year.It is not neccessary to use all the tables.
 Votes:  Id [ number]  PostId [ number]  VoteTypeId [ number]  UserId [ number]  CreationDate [ time]  BountyAmount [ number] 
SELECT CONCAT(TIME_TO_STR(CreationDate, '%Y'), '-', TIME_TO_STR(CreationDate, '%m')) AS dt, COUNT(1) AS num_mentions FROM Posts WHERE Title LIKE '%javascript%' GROUP BY CONCAT(TIME_TO_STR(CreationDate, '%Y'), '-', TIME_TO_STR(CreationDate, '%m'))