Question

如果有一张表格显示一个组织成员所获得的奖励，我试图列出在给定日期之后获得三个或更多奖励的所有成员，并列出这些成员所获得的所有奖励。我有一个能够正确列出成员的查询，但每个成员只显示一行，我试图查看他们的所有奖项。

每个奖项（“奖励”）的表格中都有一行，奖励类型和获奖日期（“Awarddate”）。

这就是我所拥有的：

SELECT Membername, Award, Awarddate,COUNT(Membername) 
FROM awards 
WHERE Awarddate > '2011-06-30' 
GROUP BY Membername HAVING COUNT(Membername) > 2

建议？

Answer 1

您可以使用GROUP_CONCAT()聚合函数：

SELECT Membername
     , COUNT(*)                                    AS NumberOfAwards
     , GROUP_CONCAT(Award ORDER BY Awarddate)      AS Awards
     , GROUP_CONCAT(Awarddate ORDER BY Awarddate)  AS AwardDates
FROM awards 
WHERE Awarddate > '2011-06-30' 
GROUP BY Membername 
HAVING COUNT(*) > 2

Answer 2

SELECT a.Membername, a.Award, a.Awarddate, Awardcount.Awards
FROM awards a
JOIN
  ( SELECT Membername, COUNT(*) AS Awards
    FROM awards
    WHERE Awarddate > '2011-06-30' 
    GROUP BY Membername 
    HAVING Awards > 2 ) Awardcount
ON a.Membername = Awardcount.Membername

修改：仅列出在给定日期之后获得的奖励，按照ypercube的建议为此查询添加一行：

WHERE a.Awarddate > '2011-06-30'

mysql - 按计数选择行组？

2 个答案: