Question

我有两张表，Quiz＆amp; Winners

Quiz Table:
id name      pub_date   type   theme
1  bday quiz 2014-01-03 random fun

Winners Table:
id quizId winner points match_date
1  1      Nick   100    2016-02-29
2  1      Mick   156    2016-03-04
3  1      Sara   199    2016-03-06

-> `quizId` references to `id` in Quiz Table

我想要实现的目标是获得一个测验＆amp;它在单个html可排序表格行中的获胜者如下：

id name       pub_date   type    theme 2016-03-06 2016-03-05 2016-03-04 ...
1  bday quiz  2014-01-03  random fun    199                   156

我正在尝试这样的事情：

SELECT Quiz.id,Quiz.name,Quiz.pub_date,Quiz.type,Quiz.theme,Winners.winner 
FROM Quiz,Winners 
WHERE Quiz.id = Winners.quizId AND 
Quiz.pub_date > '2015-03-01' AND  
Quiz.pub_date < '2016-03-06' AND 
Winners.match_date > '2016-02-01' AND 
Winners.match_date < '2016-03-06' 
ORDER BY Winners.points DESC 
LIMIT 100

此方法效果很好，但LIMIT条件返回100行，而我需要100个测验＆amp;他们的赢家也重复内容。

我想到的另一种方法是首先调用每个100个测验行。获得每个测验的获胜者，在这种情况下，我不能按优胜者的分数对测验进行排序。

Answer 1

如果你想拥有100场比赛的所有获胜者：

SELECT *
FROM Quiz AS q
JOIN (
  SELECT @rn:=@rn+1 AS rank, q2.id, z.p AS m, z.mp AS n
  FROM Quiz AS q2
  JOIN
  ( SELECT MAX(w.points) AS p, w.quizId AS mp
    FROM Winners AS w
    WHERE w.match_date BETWEEN '2013-03-01' AND '2016-03-06'
    GROUP BY w.quizId
  ) AS z ON z.mp = q2.id, (SELECT @rn:=0) t2
) AS u ON u.id = q.id
JOIN Winners AS w2 ON w2.quizId = n
WHERE rank <= 2 AND m = points

工作示例：http://sqlfiddle.com/#!9/5c6d8/2

如果要将其更改为100。您需要修改rank <= 2。我只是想知道它适用于2个测验。

Answer 2

你可能想试试这个：

SELECT Quiz.id,Quiz.name,Quiz.pub_date,Quiz.type,Quiz.theme,Winners.winner 
FROM Quiz as Quiz
INNER JOIN Winners as Winners ON Quiz.id =  Winners.quizId
WHERE 
Quiz.pub_date > '2015-03-01' AND  
Quiz.pub_date < '2016-03-06' AND 
Winners.match_date > '2016-02-01' AND 
Winners.match_date < '2016-03-06' 
GROUP BY Winners.id
ORDER BY Winners.points DESC 
LIMIT 100

不确定此输出并且未检查代码

Answer 3

在选择后尝试使用addind distinct。它将消除所选行集的重复行。

SELECT distinct Quiz.id,Quiz.name,Quiz.pub_date,Quiz.type,Quiz.theme,Winners.winner 
FROM Quiz,Winners 
WHERE Quiz.id = Winners.quizId AND 
Quiz.pub_date > '2015-03-01' AND  
Quiz.pub_date < '2016-03-06' AND 
Winners.match_date > '2016-02-01' AND 
Winners.match_date < '2016-03-06' 
ORDER BY Winners.points DESC 
LIMIT 100

SELECT * FROM表A并获取表B中与特定字段匹配的值对应的值

3 个答案: