下面是一些代码，它们应该可以生成您所需的结果。

#DROP TABLE IF EXISTS deskWeight;

CREATE TABLE deskWeight (desk INT UNSIGNED, player INT UNSIGNED, amount INT UNSIGNED, weight INT UNSIGNED, `timestamp` TIME);

INSERT INTO deskWeight VALUES
    (1, 1, 2, 10, '13:00'),
    (1, 1, 1, 15, '14:00'),
    (2, 1, 5, 20, '13:00'),
    (2, 1, 3, 5, '15:00'),
    (3, 2, 5, 6, '13:00'),
    (3, 2, 2, 30, '14:00'),
    (4, 2, 1, 10, '15:00'),
    (4, 2, 6, 3, '13:00');

SELECT A.player, SUM(A.weight / B.weightSum * A.amount) weightedAmount FROM 
    (
    SELECT A.player, B.weight, B.amount FROM
        (
        SELECT desk, player, MAX(`timestamp`) timestampMax FROM deskWeight GROUP BY desk, player
        ) A
    INNER JOIN
        deskWeight B
    ON A.desk = B.desk AND A.player = B.player AND A.timestampMax = B.`timestamp`
    ) A
INNER JOIN
    (
    SELECT A.player, SUM(B.weight) weightSum FROM
        (
        SELECT desk, player, MAX(`timestamp`) timestampMax FROM deskWeight GROUP BY desk, player
        ) A
    INNER JOIN
        deskWeight B
    ON A.desk = B.desk AND A.player = B.player AND A.timestampMax = B.`timestamp`
    GROUP BY A.player
    ) B
ON A.player = B.player
GROUP BY player;

此致，
詹姆斯

谢谢!
我设法用这个查询做到了这一点：

SELECT player, sum(aw)/sum(weight) as total, sum(weight) as weight, max(timestamp) as timestamp FROM
    (
        SELECT player, desk, amount*weight as aw, weight, timestamp FROM 
        (
            (SELECT player as p1, desk as d1, max(timestamp) as maxTs FROM playersDb.player_stats group by player, desk) mts
            inner join
            (SELECT * FROM playersDb.player_stats) data
        on data.player = mts.p1 and data.desk = mts.d1 and data.timestamp = mts.maxTs
        )
    ) t
group by player

拉兹