显示交付最大交货的供应商名称（嵌套查询）？

select s.sname, sum(sp.qty)
  from s,
       sp,
       (select max(qty) val
          from (select sum(sp.qty) qty
                  from s, sp, p
                 where sp.p = p.p
                   and sp.s = s.s
                 group y s.sname)) max_q
 where sp.s = s.s
 group by s.sname
having sum(sp.qty) = max_q.val

SELECT SNAME FROM S, SP WHERE S.S = SP.S AND QTY = (SELECT MAX(QTY) FROM SP)