Question

此查询工作正常：

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 [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

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]

现在我还有一个来自RACE CANDIDATES TABLE的字段需要显示在查询中。它为失败者返回0，为获胜者返回1。此列名为Winner。当我运行以下查询时：

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]

我收到错误消息： “消息8117，级别16，状态1，行6 操作数数据类型位对于max运算符无效。“

这是否意味着我可能会被搞砸？因为在我的第一个声明中，我将候选人数字别名为Winner，也许如果我改变它，它就会消失。这是导致错误的原因吗？或者是因为返回“0”或“1”？

当我运行SELECT * FROM [RACE CANDIDATES]时，它会返回带有正确“0”或“1”的获胜者列。

这是我的最后一期，我保证。

感谢所有指导我度过这场灾难的人。

Answer 1

由于BIT列为1或0，因此您无法对其MAX()进行申请。我在其他论坛中看到的唯一选择是将其转换为tinyint。像这样。看看是否有效。

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 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  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]

选举查询希望最后一个

1 个答案: