Question

我有一个包含以下列的表：

dayoftheweek (VARCHAR)
player (VARCHAR)
score (INT)

对于每位玩家，有3分，4分或5分。我必须计算每周每位球员最好3分的平均值。

我正在思考

SELECT dayoftheweek, player, (SUM(score) / 3) AS average_score
FROM (SELECT dayoftheweek, player, score
      FROM scoretable
      GROUP BY dayoftheweek, player
      ORDER BY score
      LIMIT 0, 3) AS query

但（显然）只给了我整体前三个记录.. 有人可以把我放在正确的方向吗？

干杯，马塞尔

Answer 1

你应该写：

SELECT dayoftheweek,
       player,
       ( SELECT AVG(score)
           FROM ( SELECT inner.score
                    FROM scoretable AS inner
                   WHERE inner.dayoftheweek = outer.dayoftheweek
                    AND inner.player = outer.player
                   ORDER
                      BY inner.score DESC
                   LIMIT 3
                )
       ) AS best_score_avg
  FROM scoretable AS outer
;

（免责声明：未经测试。）

请注意，我使用ORDER BY ... DESC来获得三个最高分数，但如果这些分数是高尔夫分数或其中最佳分数是最少分数，那么您需要将DESC更改为ASC（或者只是将其删除）。

mysql：每个类别的SUM 3记录

1 个答案: