เลือกแท็กที่แตกต่างจากโพสต์ ไม่จำเป็นต้องใช้ตารางทั้งหมด
select distinct tags from posts.It is not neccessary to use all the tables.
 PostsWithDeleted:  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 t.Id, t.TagName, COUNT(DISTINCT OwnerUserId) AS cnt FROM PostTags AS pt LEFT JOIN (SELECT Id, OwnerUserId FROM Posts WHERE YEAR(CreationDate) = 2018 OR YEAR(CreationDate) = 2017 OR YEAR(CreationDate) = 2016 OR YEAR(CreationDate) = 2015 OR YEAR(CreationDate) = 2014 AND NOT Tags IS NULL) AS p ON pt.PostId = p.Id LEFT JOIN Users AS u ON u.Id = p.OwnerUserId LEFT JOIN Tags AS t ON pt.TagId = t.Id WHERE NOT pt.TagId IS NULL AND (LOWER(Location) LIKE '%nederland%' OR LOWER(Location) LIKE '%netherland%') GROUP BY t.Id, t.TagName ORDER BY cnt DESC