Question

如何将一个表中的行连接到另一个表上给定列的MAX值的行？

例如，我有一个auctions表和一个auction_bids表。我想以bid_amount表中的最高出价（即auction_id列和x = auction_bids的最高值）加入拍卖表。

Answer 1

令人烦恼的复杂。在每个获胜的auction_bid中，你最好有一个“胜利者”的旗帜。

SELECT * FROM auctions a
INNER JOIN 
(
    /* now get just the winning rows */
    SELECT * FROM auction_bids x
    INNER JOIN
    (
        /* how to tell the winners */
        SELECT auction_id, MAX(bid_amount) as winner
        FROM auction_bids
        GROUP BY auction_id
    ) y
    ON x.auction_id = y.auction_id
    AND x.bid_amount = y.winner
) b
ON a.auction_id = b.auction_id

请注意，零出价的拍卖根本不会被列出，并且每个并列出价都会出现一次带有关系的拍卖（可能会发生？）。

Answer 2

试试这个：

SELECT a.id, MAX(ab.bid_amount)
FROM auctions AS a
INNER JOIN action_bids AS ab 
   ON a.id = ab.auction_id
GROUP BY a.id;

根据需要在SELECT和GROUP BY条款中添加更多列。

Answer 3

试试这个：

SELECT a.*, bid_amount
  FROM auction a INNER JOIN 
    (
     SELECT auction_id, MAX(bid_amount)  AS bid_amount
       FROM auction_bids
         WHERE acution_id = x
         GROUP BY auction_id
    ) b
    ON a.auction_id = b.auction_id

Answer 4

试试这个

 Select A.ID,max(AB.bit_amount) 
 From  auctions A Inner Join Auction_bids AB on A.ID = AB.auction_ID
 Where A.ID = x
 Group By A.ID

Answer 5

基本上，您必须使用子查询在实际连接中执行此操作。

Select bid as highest_bid
  from auctions
    left outer join auctions_bids on action_bids.ref_no = auctions.ref_no
     and (select max(bid) from auctions_bids as ab 
           where auctions_bid.ref_no = a2.ref_no)

在另一个表中加入MAX行的行？

5 个答案: