Q&A for professional and enthusiast programmers
with two_answers as ( select min(a.Id) first, max(a.Id) last from Posts q join Posts a on q.Id = a.ParentId where q.AnswerCount = 2 group by q.Id having getdate() - max(a.CreationDate) > 30 ) select min(datediff(hour, f.CreationDate, l.CreationDate)), avg(cast(f.Score as float)) first, avg(cast(l.Score as float)) last, avg(cast(isnull(f.Score, 0) as float) - cast(isnull(l.Score, 0) as float)) delta from two_answers join Posts f on f.Id = first join Posts l on l.Id = last where isnull(f.Score, 0) >= 0 and isnull(l.Score, 0) >= 0 and f.CreationDate < l.CreationDate and datediff(month, f.CreationDate, l.CreationDate) < 1 group by datediff(hour, f.CreationDate, l.CreationDate) order by datediff(hour, f.CreationDate, l.CreationDate)