Q&A for professional and enthusiast programmers
select dateadd(week, datediff(week, 0, c.CreationDate), 0) wk, count(*) from comments c where c.CreationDate < dateadd(week, datediff(week, 0, getdate()), 0)-1 group by dateadd(week, datediff(week, 0, c.CreationDate), 0) order by dateadd(week, datediff(week, 0, c.CreationDate), 0)