查找排名的sql

Question

我有一個參與者表：

userid name 
1  John 
2  Sam 
3  Harry 

而且有比賽表：

contestid contestname 
1   abc 
2   def 
3   ghi 

得分表看起來像這樣：

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 

現在，考慮到userid，我需要在所有比賽中找出他的排名。 排名應該基於比賽和分數。

輸出應該是這樣的userid=1：

contestid rank 
1   3 
2   1 
3   Nil 

我怎樣才能得到這個輸出？

Answer 1

如果你需要通過排名分數和比賽那就試試這個

---

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

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2.如果您需要它排名得分然後嘗試這個

---

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

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3.如果你想UserName和競賽名稱那就試試這個

---

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