Q&A for gardeners and landscapers
-- Find users who have exactly one post -- with that post being a question -- and the question has the [identification] tag -- and the user was never seen again SELECT Users.Id AS [User Link], Posts.Id AS [Post Link], Users.CreationDate AS Joined FROM Users INNER JOIN Posts ON Posts.OwnerUserId = Users.Id WHERE Posts.ParentId IS NULL AND -- ParentId is NULL if post is a question Users.CreationDate = Users.LastAccessDate AND Users.Id in ( -- Users with exactly one question SELECT Users.Id FROM Users INNER JOIN Posts ON Posts.OwnerUserId = Users.Id WHERE Posts.ParentId IS NULL GROUP BY Users.id HAVING Count(Posts.Id) = 1 ) AND Users.Id NOT IN ( -- Users with 1 or more answers SELECT Users.Id FROM Users INNER JOIN Posts ON Posts.OwnerUserId = Users.Id WHERE Posts.ParentId IS NOT NULL GROUP BY Users.id HAVING Count(Posts.Id) > 0 ) ORDER BY Users.Id DESC -- newest users first.