选举查询 - 另一个问题。主要的答案

【问题标题】：Election Query -yet another issue. Major选举查询 - 另一个问题。主要的
【发布时间】：2014-02-04 19:00:44
【问题描述】：

这个查询给我带来了我想要的结果。那太好了！

select  rc.[race number],
    max(case when seqnum = 1 then [candidate num] end) as Winner,
    max(case when seqnum = 1 then Votes end) as WinningVotes,
    max(case when seqnum = 1 then party end) as WinningParty,
    max(case when seqnum = 1 then leader end) as Winner1,
    max(case when seqnum = 1 then winner end) as WinnerSelected,
    max(case when seqnum = 1 then [leader percent] end) as WinnerPercent,
    max(case when seqnum = 2 then [candidate num] end) as Loser,
    max(case when seqnum = 2 then Votes end) as LosingVotes,
    max(case when seqnum = 2 then party end) as LosingParty,
    max(case when seqnum = 2 then leader2 end) as Loser2,
    max(case when seqnum = 2 then [leader2 percent] end) as LoserPercent,
    max(case when seqnum = 2 then winner end) as LoserSelected

from 
(
select  rc.[race number],
        rc.[candidate num],
        rc.[Votes],
        rc.[winner],
        c.[party],
        r.[leader],
        r.[leader percent],
        r.[leader2],
        r.[leader2 percent],
            row_number() over (partition by rc.[race number] order by votes desc) as seqnum
    from    dbo.[RACE CANDIDATES] rc
    inner join dbo.[CANDIDATE] c    on  rc.[candidate num]  = c.[candidate number]
    inner join dbo.[RACE] r
     on rc.[race number] = r.[race number]          
) rc
group by rc.[race number]

我现在遇到的问题是我需要在查询中包含的 RACE 表中有一个 title1 字段。我无法绑定该多部分标识符。这就是我在论坛上的全部寻找和破坏的开始。

每场比赛都有一个头衔和 2 名候选人。我试图将两个候选人和领先数据放入一个行集中。现在，我唯一缺少的是 title1 字段！啊啊啊！它永远不会结束。

我认为我不能在 max(case select 中使用它，因为它肯定会重复比赛编号。

我希望这是有道理的。很抱歉在论坛上浪费了这么多带宽。

【问题讨论】：

标签： sql-server multiple-columns

【解决方案1】：

select  rc.[race number] AS RaceNumber,
    max(case when seqnum = 1 then title1 end) as title1,
    max(case when seqnum = 1 then [candidate num] end) as Winner,
    max(case when seqnum = 1 then Votes end) as WinningVotes,
    max(case when seqnum = 1 then party end) as WinningParty,
    max(case when seqnum = 1 then leader end) as Winner1,
    max(case when seqnum = 1 then CAST(winner AS tinyint) end) as WinnerSelected,
    max(case when seqnum = 1 then [leader percent] end) as WinnerPercent,
    max(case when seqnum = 2 then [candidate num] end) as Loser,
    max(case when seqnum = 2 then Votes end) as LosingVotes,
    max(case when seqnum = 2 then party end) as LosingParty,
    max(case when seqnum = 2 then leader2 end) as Loser2,
    max(case when seqnum = 2 then [leader2 percent] end) as LoserPercent,
    max(case when seqnum = 2 then CAST(winner AS tinyint) end) as LoserSelected


from 
(
select  
        r.title1,
        rc.[race number],
        rc.[candidate num],
        rc.[Votes],
        rc.[winner],
        c.[party],
        r.[leader],
        r.[leader percent],
        r.[leader2],
        r.[leader2 percent],

            row_number() over (partition by rc.[race number] order by votes desc) as seqnum
    from    dbo.[RACE CANDIDATES] rc
    inner join dbo.[CANDIDATE] c    on  rc.[candidate num]  = c.[candidate number]
    inner join dbo.[RACE] r
     on rc.[race number] = r.[race number] 

) rc
group by rc.[race number]

我明白了。谢谢大家！！！

【讨论】：