Question

我今天早些时候收到了很多帮助，但是在我的查询中实现它比我想象的要困难得多。我的真实查询包括几个左连接。

我想添加两列，T3MOutput和T1GOutput，显示基于的10-1排名 T3M和T1G列。那里的最高值应该在排名范围内得到10，最低（负值）应该得到1.注意！赛马起跑时可少于15匹马。在10个最佳值恢复10-1之后，其余值也应该得到值1.

小提琴：http://sqlfiddle.com/#!2/9c5fc/4

我应该在哪里实现这行代码或其他解决方案？我只在整个过程中获得值1.

(SELECT @row:=11 r) rows

以下是所有代码：

SELECT

base.number as NR,
rank.rpo AS RPO,
rank.rsp AS RSP,
rank.rsv AS RSV,
timer.t3m AS T3M, CASE WHEN @row>1 THEN @row:=@row-1 ELSE 1 END T3MOutput,
timer.t1g AS T1G, CASE WHEN @row>1 THEN @row:=@row-1 ELSE 1 END T1GOutput

FROM round
LEFT JOIN base 
ON round.id = base.round_id 

LEFT JOIN rank 
ON  round.id = rank.round_id AND rank.number = base.number

LEFT JOIN timer    
ON round.id = timer.round_id AND timer.number = base.number

ORDER BY nr

Answer 1

第一

SELECT MIN(timer.t3m) AS MinT3M, MAX(timer.t3m) AS MaxT3M,
  MIN(timer.t1g) AS MinT1G, MAX(timer.t1g) AS MaxT1G
  FROM round INNER JOIN timer ON round.id = timer.round_id
  WHERE round.round_date = '2013-03-22' 
    AND round.gameform = 'V65'
    AND round.gameform_info = 'V65-1'
    AND round.gameform not like "OSPEC";

然后你可以使用理查德在我输入时提出的计算。

请参阅使用您的数据的SQL小提琴here。

Answer 2

假设您正在尝试对这些值进行排名，一种可能的方法是首先确定T3M和T1G的最小值和最大值，然后使用以下内容：

SELECT ...,
       ((T3M-@T3M_Min)/(@T3M_Max-@T3M_Min))*9+1 as T3MOutput,
       ((T1G-@T1G_Min)/(@T1G_Max-@T1G_Min))*9+1 as T1GOutput

可能必须转换为整数值

Answer 3

这有点棘手，也许这就是你要找的东西？

SELECT
  q2.*,
  CASE WHEN @row>1 AND T1G is not NULL THEN @row:=@row-1 ELSE 1 END T1GOutput
FROM (

SELECT
  q1.*,
  CASE WHEN @row>1 AND T3M is not NULL THEN @row:=@row-1 ELSE 1 END T3MOutput
FROM (
SELECT
  base.number as NR,
  rank.rpo as RPO,
  rank.rsp as RSP,
  rank.rsv as RSV,
  timer.t3m as T3M,
  timer.t1g AS T1G
FROM

  round LEFT JOIN base 
  ON round.id = base.round_id 

  LEFT JOIN rank 
  ON round.id = rank.round_id and rank.number = base.number

  LEFT JOIN timer    
  ON round.id = timer.round_id and timer.number = base.number

order by T3M DESC
  ) q1, (SELECT @row:=11) rows
) q2,  (SELECT @row:=11) rows
ORDER BY
  T1G

请参阅小提琴here。

将十进制值转换为前十名

3 个答案: