Question

我有一个参与者表：

userid   name
1        John
2        Sam
3        Harry

还有比赛表：

contestid contestname
1         abc
2         def
3         ghi

分数表如下所示：

id  contestid userid score
1   1         1      200
2   1         2      300
3   1         3      250
4   2         1      500
5   2         2      400
6   3         2      800

现在，鉴于userid，我需要在所有比赛中找出他的排名。排名应基于比赛和分数。

userid=1的输出应该是这样的：

contestid rank
1         3
2         1
3         Nil

如何获得此输出？

Answer 1

1。如果您需要它按分数和竞赛排名，请尝试此

SET @rank := 0;
SET @prev := NULL;

SELECT contestid,userid,score,Rank FROM
(
SELECT contestid,userid,score,@rank := IF(@prev = contestid, @rank + 1, 1) AS rank,
       @prev := contestid
FROM scores ORDER BY contestid, score DESC
) S Where userid = 1

FIDDLE DEMO

2. 如果您需要按分数排名，请尝试此

SELECT contestid,userid,score, FIND_IN_SET( score, 
       (SELECT GROUP_CONCAT(score ORDER BY score DESC) FROM scores)) AS rank
FROM scores
Where UserId = 1

Fiddle Demo

3. 如果您想要UserName和COntest Name，请尝试使用

SELECT C.contestname,P.name,S.score, FIND_IN_SET( S.score, 
       (SELECT GROUP_CONCAT(score ORDER BY score DESC) FROM scores)) AS rank
FROM scores S Join participant P ON P.userid =C.userid 
              Join contest  C ON C.contestid = S.contestid 
Where UserId = 1

在各种比赛sql中找到参与者的等级

1 个答案: