Q&A for historians and history buffs
WITH OnTopicPosts AS ( SELECT Posts.Id, Posts.OwnerUserId, Tags.Tagname FROM Posts INNER JOIN PostTags ON PostTags.PostId = Posts.Id INNER JOIN Tags ON Tags.Id = PostTags.TagId WHERE Tags.Tagname IN ('image-processing', 'signal-processing') ), ParticipatingUsers AS ( SELECT OnTopicPosts.Tagname, OnTopicPosts.OwnerUserId AS Id FROM OnTopicPosts UNION SELECT OnTopicPosts.Tagname, Comments.UserId AS Id FROM Comments INNER JOIN OnTopicPosts ON Comments.PostId = OnTopicPosts.Id UNION SELECT OnTopicPosts.Tagname, Votes.UserId AS Id FROM Votes INNER JOIN OnTopicPosts ON Votes.PostId = OnTopicPosts.Id ), LocalUsers AS ( SELECT Users.Id, COUNT(*) AS postcount FROM ParticipatingUsers INNER JOIN Users ON ParticipatingUsers.Id = Users.Id WHERE LOWER(Users.Location) LIKE '%tampere%' OR LOWER(Users.Location) LIKE '%helsinki%' OR LOWER(Users.Location) LIKE '%finland%' GROUP BY Users.Id ) SELECT LocalUsers.postcount, 'https://stackoverflow.com/users/' + CAST(Users.Id AS VARCHAR(100)), Users.DisplayName, Users.WebsiteUrl, Users.Location, Users.UpVotes, Users.DownVotes FROM LocalUsers INNER JOIN Users ON LocalUsers.Id = Users.Id;