一天 "select * from T_news where datediff(day,addtime,getdate())=0";

三天 "select * from T_news where datediff(day,addtime,getdate())<= 2 and datediff(day,addtime,getdate())>= 0";

一周 "SELECT * FROM T_news WHERE (DATEPART(wk, addtime) = DATEPART(wk, GETDATE())) AND (DATEPART(yy, addtime) = DATEPART(yy, GETDATE()))";

一月"SELECT * FROM T_news WHERE (DATEPART(yy, addtime) = DATEPART(yy, GETDATE())) AND (DATEPART(mm, addtime) = DATEPART(mm, GETDATE()))";

一季度 "select * from T_news where DATEPART(qq, addtime) = DATEPART(qq, GETDATE()) and DATEPART(yy, addtime) = DATEPART(yy, GETDATE())";