mysql - MySQL : Self join 中的分组最大值列

Question

包含名称、电子邮件、拍卖 ID 和出价的 MySQL 表。我正在尝试通过 auction_id 使用 GROUP 时从最高出价行获取最高出价和电子邮件地址。

我可以获得返回的 MAX 出价金额，但返回的电子邮件地址不是用于 MAX 出价的。

SELECT email, MAX(bid) FROM `kisd_wdm_bidders` GROUP BY auction_id 

Answer 1

您必须执行SELF JOIN(不准确)

SELECT T1.auction_id,T1.email,T1.bid
    FROM kisd_wdm_bidders AS T1
    INNER JOIN (
        SELECT auction_id, MAX(bid) AS max_bid
        FROM kisd_wdm_bidders
        GROUP BY auction_id
    ) AS T2
    ON T1.auction_id  = T2.auction_id AND T2.max_bid =T1.bid

希望这对您有所帮助。