instruction: Posts with the longest and oldest comment chat. ...where the SUM(comment after post creation) is the largest
response: SELECT Posts.Id AS "post_link", 1.0 * SUM(CAST(CAST((JULIANDAY(Comments.CreationDate) - JULIANDAY(Posts.CreationDate)) AS INT) AS INT)) / 365 / 86400 AS SumT FROM Posts, Comments WHERE Comments.CreationDate >= Posts.CreationDate AND Comments.PostId = Posts.Id GROUP BY Posts.Id ORDER BY SumT DESC LIMIT 100