PHP MYSQL组排名查询 [英] PHP MYSQL group ranking query

问题描述

CREATE TABLE `players` (
 `pid` int(2) NOT NULL AUTO_INCREMENT,
 `name` varchar(50) NOT NULL,
`team` varchar(20) NOT NULL,
`age` int(2) NOT NULL,
PRIMARY KEY (`pid`),
UNIQUE KEY `name` (`name`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1;


INSERT INTO `players` (`pid`, `name`, `age`, `team`) VALUES
(1, 'Samual', 25, 'aa'),
(2, 'Vino', 20, 'bb'),
(3, 'John', 20, 'dd'),
(4, 'Andy', 22, 'cc'),
(5, 'Brian', 21, 'dd'),
(6, 'Dew', 24, 'xx'),
(7, 'Kris', 25, 'qq'),
(8, 'William', 26, 'cc'),
(9, 'George', 23, 'nn'),
(10, 'Peter', 19, 'aa'),
(11, 'Tom', 20, 'aa'),
(12, 'Andre', 20, 'aa');

在上表中，我希望该查询以分数的降序获取球员的排名.

In the above table, I want this query to fetch the ranking of the players in descending order of their scores.

SELECT pid, name, age, team, rank FROM
(SELECT pid, name, age, team,
@curRank := IF(@prevRank = age, @curRank, @incRank) AS rank, 
@incRank := @incRank + 1, 
@prevRank := age
FROM players p, (
SELECT @curRank :=0, @prevRank := NULL, @incRank := 1
) r 
ORDER BY age DESC) s WHERE team='aa'

它给了我以下结果:

Name        |     Age    | Rank  
####--------------------------------   
Samual      |     25     | 2    
Tom         |     20     | 8    
Andre       |     20     | 8    
Peter       |     19     | 12  

但是我希望以这种方式返回结果:

But I want the results to be returned in this manner:

Name        |     Age    | Rank  
####--------------------------------   
Samual      |     25     | 1    
Tom         |     20     | 2    
Andre       |     20     | 2    
Peter       |     19     | 4   

因此，进行查询以给出特定组内的排名.

Therefore, making the query to give me the rank within a particular group.

推荐答案

您需要将查询中的where子句移动为

You need to move the where clause inside the query as

SELECT pid, 
name, 
age, 
team, 
rank 
FROM (
 SELECT pid, name, age, team,
 @curRank := IF(@prevRank = age, @curRank, @incRank) AS rank, 
 @incRank := @incRank + 1, 
 @prevRank := age
 FROM players p, (SELECT @curRank :=0, @prevRank := NULL, @incRank := 1) r
 WHERE team='aa'
 ORDER BY age DESC
) s 

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