Question

我有一张称为“玩家”的表格，其中包含蒂姆，鲍勃和乔恩玩过的3场比赛的得分。

playid | name | score
1      | Tim  | 10
1      | Bob  | 5
2      | Tim  | 5
2      | Bob  | 10
3      | Tim  | 5
3      | Bob  | 10
3      | Jon  | 4

我希望能够计算出Tim，Bob和Jon获得第二名的次数，即Tim = 2，Bob = 1，Jon = 0。

我有以下查询：

SELECT name FROM players WHERE playid = 1 ORDER BY score Desc LIMIT 1, 1

哪个人的名字在第一场比赛中名列第二，即鲍勃，但我不知道如何将其扩展到所有游戏和玩家。最终，我还希望能够计算出它们获得第三，第四等的次数。

预先感谢

Answer 1

尝试以下一项：

SELECT count(playid), name, score
FROM `players` 
WHERE score = (SELECT MAX(score) FROM players WHERE score < (SELECT MAX(score) FROM players))
GROUP BY score, name;

Answer 2

您可以在下面使用此查询来找到View个人：

secondly-ranked

Rextester Demo

Answer 3

具有多个联接和分组：

select pl.name, ifnull(counter, 0) counter from (
  select distinct name from players) pl 
left join (
select players.name, count(*) counter from players
inner join (
  select p.playid, max(p.score) as secondscore from (
    select players.* from players
    left join (
      select playid, max(score) as maxscore
      from players 
      group by playid) p
    on p.playid = players.playid and p.maxscore = players.score
    where p.maxscore is null) p
  group by p.playid
) p
on p.playid = players.playid and p.secondscore = players.score
group by players.name) p 
on p.name = pl.name

请参见demo

Answer 4

根据Raymond Nijland的评论，在MySQL 8.0+中，您可以使用窗口函数来实现此目的：

SELECT name, COUNT(*) AS second_place_count
FROM (
    SELECT
        name,
        playid,
        ROW_NUMBER() OVER (PARTITION BY playid ORDER BY score DESC) AS rn
    FROM players
) AS ranks
WHERE ranks.rn = 2
GROUP BY name

...或者如果要将其扩展到所有位置：

SELECT 
    name,
    rn AS place,
    COUNT(*) AS place_count
FROM (
    SELECT
        name,
        playid,
        ROW_NUMBER() OVER (PARTITION BY playid ORDER BY score DESC) AS rn
    FROM players
) AS ranks
GROUP BY
    name,
    rn

MYSQL-计算一个人在比赛中获得第二名的次数

4 个答案: