Sum（Max（））子查询

Question

我正在尝试仅为求和列选择MAX值

select rental.member_id,
       rental.rental_id,
       sum(rental_line.Qty) as TotalRentals
  from Rental 
 INNER JOIN rental_line 
    on rental.rental_id =rental_line.rental_id 
where MONTHS_BETWEEN(sysdate, datein)<(12)
group by rental.member_id, 
         rental.rental_id, 
         SUM(TotalRentals) =  MAX(SUM(TotalRentals));

有什么想法吗？

Answer 1

您可以按TotalRentals（3）降序排序查询的结果集，然后使用rownum伪列获取第一行：

select member_id
     , rental_id
     , TotalRentals
  from ( select rental.member_id
              , rental.rental_id
              , sum(rental_line.Qty) as TotalRentals
           from Rental 
          INNER JOIN rental_line 
             on rental.rental_id =rental_line.rental_id 
          where MONTHS_BETWEEN(sysdate, datein)<(12)
          group by rental.member_id, 
                   rental.rental_id
          order by 3 desc
      ) 
where rownum = 1