Q&A for Drupal developers and administrators
SELECT TOP(##num?100##) u.Id AS [User Link], COUNT(DISTINCT pt.TagId) AS [# of tags] FROM Users u INNER JOIN Posts a ON a.OwnerUserId=u.Id INNER JOIN Posts q ON a.ParentId=q.Id INNER JOIN PostTags pt ON pt.PostId=q.Id GROUP BY u.Id ORDER BY COUNT(DISTINCT pt.TagId) DESC