选择MySQL中日期最高的行

Question

我有一个表，每个用户每天都有行。

我想按月和年分组以生成给定月份的摘要。

问题是，它正在选择第一行的值（即9月1日而不是9月5日），这给了我错误的数字，因为我想要该列的最新运行总计。

我努力了：

SELECT SUM(prospectCount) FROM report_sales_day AS RSD
WHERE userId = 93
AND YEAR(date) = YEAR('2014-09-01')
AND MONTH(date) = MONTH('2014-09-01')
AND (SELECT MAX(RSDI.date)
     FROM report_sales_day AS RSDI
     WHERE MONTH(RSDI.date) = MONTH(RSD.date)
     AND YEAR(RSDI.date) = YEAR(RSD.date)) = MAX(date)
GROUP BY YEAR(date), MONTH(date)

但这只是给我一个错误，我想不出其他任何方法来做到这一点。

有谁知道我需要做些什么才能达到我想要的结果？

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我的表中有很多列，有些需要SUM（），AVG（），而另一些只需要给定月份的最后一个值。

Answer 1

尝试这个：

SELECT SUM(prospectCount) 
FROM report_sales_day AS RSD 
INNER JOIN (SELECT userId, MAX(RSDI.date) AS `date`
                FROM report_sales_day AS RSDI
                WHERE MONTH(RSDI.date) = MONTH('2014-09-01') AND YEAR(RSDI.date) = YEAR('2014-09-01')
             ) AS A ON RSD.userId = A.userId AND RSD.date = A.date 
WHERE userId = 93 AND YEAR(RSD.date) = YEAR('2014-09-01') AND 
        MONTH(RSD.date) = MONTH('2014-09-01')
GROUP BY YEAR(RSD.date), MONTH(RSD.date)

Answer 2

我认为您的查询应该是这样的。 您必须在`date`附近使用反引号

SELECT SUM(prospectCount) FROM report_sales_day AS RSD
WHERE userId = 93
AND YEAR(`date`) = YEAR('2014-09-01')
AND MONTH(`date`) = MONTH('2014-09-01')
AND MAX(`date`) = (SELECT MAX(RSDI.date)
  FROM report_sales_day 
  WHERE MONTH(RSDI.date) = MONTH(RSD.date)
  AND YEAR(RSDI.date) = YEAR(RSD.date))
GROUP BY YEAR(`date`), MONTH(`date`)