首先：您想要的功能称为sliding window和ranking。Oracle 使用OVER-keyword 和rank()-function 来实现这些。MySQL 不支持这些特性，所以我们必须解决这个问题。
我使用这个答案创建了以下查询。+1如果这对你有帮助，也给他一个。
SELECT
`player_id`, `event`, `points`,
(SELECT 1 + count(*)
FROM `points`
WHERE `l`.`player_id` = `player_id`
AND `l`.`event` = `event`
AND `points` > `l`.`points`
) AS `rank`
FROM
`points` `l`
这将输出每个player_id和event的等级points。例如：假设(player_id, event, points)has(1,A,10), (1,A,5), (1,A,2), (1,A,2), (1,A,1), (2,A,0)那么输出将是
player_id event points rank
1 A 10 1
1 A 5 2
1 A 2 3
1 A 2 3
1 A 1 5
2 A 0 1
秩并不密集，所以如果你有重复的元组，你将有相同秩的输出元组以及你的秩数中的间隙。
要获取N每个的 top * 元组player_id，event您可以创建一个视图或在条件中使用子查询。视图是首选方式，但您无权在许多服务器上创建视图。
创建一个包含rankas 列的视图。
CREATE VIEW `points_view`
AS SELECT
`player_id`, `event`, `points`,
(SELECT 1 + count(*)
FROM `points`
WHERE `l`.`player_id` = `player_id`
AND `l`.`event` = `event`
AND `points` > `l`.`points`
) as `rank`
FROM
`points` `l`
从视图中获取所需的前 N 个结果：
SELECT
`player_id`, `event`, `points`
FROM `points_view`
WHERE
`event` = 'A' AND `rank` <= 5
OR
`event` = 'B' AND `rank` <= 2
OR
`event` = 'C' AND `rank` <= 3
使用条件中的等级
SELECT
`player_id`, `event`, `points`
FROM
`points` `l`
WHERE
(SELECT 1 + count(*)
FROM `points`
WHERE `l`.`player_id` = `player_id`
AND `l`.`event` = `event`
AND `points` > `l`.`points`
) <= N
要根据您的事件进一步获得不同数量的元组，您可以这样做
SELECT
`player_id`, `event`, `points`
FROM
`points` `l`
WHERE
`event` = 'A' AND
(SELECT 1 + count(*)
FROM `points`
WHERE `l`.`player_id` = `player_id`
AND `l`.`event` = `event`
AND `points` > `l`.`points`
) <= 5
OR
`event` = 'B' AND
(SELECT 1 + count(*)
FROM `points`
WHERE `l`.`player_id` = `player_id`
AND `l`.`event` = `event`
AND `points` > `l`.`points`
) <= 2
OR
`event` = 'C' AND
(SELECT 1 + count(*)
FROM `points`
WHERE `l`.`player_id` = `player_id`
AND `l`.`event` = `event`
AND `points` > `l`.`points`
) <= 3
我将只使用您的最大值N5 并忽略其他事件类型的其他元组，因为 MySQL 不会优化此查询，这会导致 3 个单独的依赖子查询。如果性能不是问题，或者您没有太多数据，请保持这种状态。
* 正如我所解释的那样，rank它并不密集，因此获取所有元组rank <= N通常会导致多于N元组。额外的元组是重复的。
从示例表中可以看出，简单地删除重复项是一个坏主意。如果您想要 and 的前 5 个结果player_id = 1，则event = A需要两个元组(1,A,2)。他们都有排名 3。但如果你删除其中一个，你最终只会得到前 4 个结果(1,A,10,1), (1,A,5,2), (1,A,2,3), (1,A,1,5)。
要获得密集排名，您可以使用此子查询
(SELECT count(DISTINCT `points`)
FROM `points`
WHERE `l`.`player_id` = `player_id`
AND `l`.`event` = `event`
AND `points` >= `l`.`points`
) as `dense_rank`
小心，因为这仍然会产生重复的等级。
编辑
要将所有事件的分数加起来为一个分数，请使用GROUP BY
SELECT
`player_id`, SUM(`points`)
FROM `points_view`
WHERE
`event` = 'A' AND `rank` <= 5
OR
`event` = 'B' AND `rank` <= 2
OR
`event` = 'C' AND `rank` <= 3
GROUP BY `player_id`
ORDER BY SUM(`points`) DESC
在分区 ( GROUP BY) 之前，结果包含正确数量的最高分，因此您可以简单地将所有分数相加。
您在这里面临的一个大问题是，既不rank也不dense_rank会给您工具为每个player_id和获得恰好 5 个元组event。例如：如果某人在事件 A 中获得 1000 倍 1 分，那么他最终将获得 1000 分，因为所有分数都会得到rank和dense_rank 1。
但又是这样ROWNUM：MySQL 不支持这个，所以我们必须模仿这个。问题ROWNUM在于它将为所有元组生成一个复合数字。但是我们想要 , 组的合player_id数event。不过，我仍在研究此解决方案。
编辑2
使用这个答案，我发现这个解决方案可以工作：
select
player_id, sum( points )
from
(
select
player_id,
event,
points,
/* increment current_pos and reset to 0 if player_id or event changes */
@current_pos := if (@current_player = player_id AND
@current_event = event, @current_pos, 0) + 1 as position,
@current_player := player_id,
@current_event := event
from
(select
/* global variable init */
@current_player := null,
@current_event := null,
@current_pos := 0) set_pos,
points
order by
player_id,
event,
points desc
) pos
WHERE
pos.event = 'A' AND pos.position <= 5
OR
pos.event = 'B' AND pos.position <= 2
OR
pos.event = 'C' AND pos.position <= 3
GROUP BY player_id
ORDER BY SUM( points ) DESC
内部查询选择 (player_id, event, points)-元组，按 player_id 和 event 对它们进行排序，最后给每个元组一个复合数，每次 player_id 或 event 更改时重置为 0。由于顺序的原因，所有具有相同 player_id 的元组都是连续的。外部查询与先前使用的查询对视图的作用相同。
Edit3（见评论）
您可以使用 OLAP ROLLUP 运算符创建中间总和或不同类型的分区。例如，查询将如下所示：
select
player_id, event, sum( points )
from
(
select
player_id,
event,
points,
/* increment current_pos and reset to 0 if player_id or event changes */
@current_pos := if (@current_player = player_id AND
@current_event = event, @current_pos, 0) + 1 as position,
@current_player := player_id,
@current_event := event
from
(select
/* global variable init */
@current_player := null,
@current_event := null,
@current_pos := 0) set_pos,
points
order by
player_id,
event,
points desc
) pos
WHERE
pos.event = 'A' AND pos.position <= 5
OR
pos.event = 'B' AND pos.position <= 2
OR
pos.event = 'C' AND pos.position <= 3
GROUP BY player_id, event WITH ROLLUP
/* NO ORDER BY HERE. SEE DOCUMENTATION ON MYSQL's ROLLUP FOR REASON */
结果现在将首先按 分组player_id, event，然后按 only分组，player_id最后按 null 分组（总结所有行）。
第一组看起来像(player_id, event, sum(points)) = {(1, A, 20), (1,B,5)}20 和 5 是关于player_id和的点的总和event。第二组的样子(player_id, event, sum(points)) = {(1,NULL,25)}。25 是关于 的所有点的总和player_id。希望有帮助。:-)