mysql获取特定结果的行号

我的网站允许用户记录出价。每个出价都单独保存并与用户Id关联。用户可以有多个出价，这些出价用于将网站上显示的全部出价相加

我在sql中尝试的是从结果集中返回用户总体出价的位置

我使用的sql如下所示，但当我使用group by命令时会出现问题-排序似乎恢复为默认的db顺序，而不是按用户出价金额的总和：

SET @rowcount = 0;
SELECT rowCount, userId FROM (
    SELECT userId, @rowcount := @rowcount + 1 as rowCount, sum(amount) as amount FROM bids group by userId order by amount desc
 ) t when product = xxxxx

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如果有人知道这是否可行，我将不胜感激。

您已经尝试过了吗

SET @rowcount = 0;
SELECT rowCount, userId FROM (
    SELECT userId, @rowcount := @rowcount + 1 as rowCount from 
     (select sum(amount) as amount, userId FROM bids group by userId) s
     order by s.amount desc
 ) t where product = xxxxx

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如果我理解正确，您可以尝试以下方式：

SELECT @rownum:=@rownum+1 ‘rank’, userId FROM (SELECT product, userId, sum(amount) AS amount FROM bids GROUP BY userId) t, (SELECT @rownum:=0) r WHERE t.product = xxxx ORDER BY t.amount DESC;

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您需要将行数增量移出子查询。并将您的

WHERE

条件放入其中，否则您的子查询将对给定用户的所有产品的出价求和

SET @rowcount = 0;
SELECT @rowCount:=@rowcount+1 as rowcount, userId, amount FROM 
 (
    SELECT userId, sum(amount) as amount 
    FROM bids 
    WHERE product = xxxxx 
    GROUP BY userId 
    ORDER BY amount DESC
 ) t