Q&A for community managers, administrators, and moderators
select p.Id, p.OwnerUserId, p.CreationDate, p.Score, p.CommentCount, p.Body from ( select OwnerUserId, MIN(CreationDate) as firstdate from Posts where convert(date, CreationDate) <= convert(date, '20180918') group by OwnerUserID ) as latest inner join Posts as p on p.OwnerUserId = latest.OwnerUserId and p.CreationDate = latest.firstdate where convert(date, p.CreationDate) >= convert(date, '20180912') AND convert(date, p.CreationDate) <= convert(date, '20180918') AND p.PostTypeId = 2