sql-server - 将值传递给派生表

Question

有没有办法将值传递给派生表查询？

在派生表中，我想从外部查询中引用一个值 ([docSVsys].[sID])。

我得到一个错误:

Msg 4104, Level 16, State 1, Line 7 The multi-part identifier "docSVsys.sID" could not be bound.

是的，我知道这个查询可以简化为无循环。
有一个必须循环并尝试将其转换为如此设置的游标。

select top 10 [docSVsys].[sID], [sI].[count]
from docSVsys 
join 
(
    select count(*) as [count]   
    from docSVenum1 as [sIt]
    where  [sIt].[sID] = [docSVsys].[sID] 
) as [sI] 
on  '1' = '1'
order by [docSVsys].[sID]

交叉应用似乎可以解决问题。 而且它比光标版本快 1/3。 下面使用交叉应用的真实查询。

SELECT [sO].[sID], [sI].[max], [sI].[avg], [sI].[stdev]
FROM docSVsys as [sO] with (nolock)
cross apply 
( 
    select [sO].[sID], max(list.match) as 'max', avg(list.match) as 'avg', stdev(list.match) as 'stdev'
    from
    (
        select #SampleSet.[sID], [match] = 200 * count(*) / CAST ( #SampleSetSummary.[count] + [sO].[textUniqueWordCount]  as numeric(8,0) ) 
        from #SampleSet with (nolock) 
        join FTSindexWordOnce as [match] with (nolock) -- this is current @sID
            on match.wordID  = #SampleSet.wordID
            and [match].[sID] = [sO].[sID]
        join #SampleSetSummary with (nolock)  -- to get the word count from the sample set
            on #SampleSetSummary.[sID] = #SampleSet.[sID] 
        group by #SampleSet.[sID], #SampleSetSummary.[count] 
    ) as list
    having max(list.match) > 60 
) as [sI]  
where [textUniqueWordCount] is not null and [textUniqueWordCount] > 4 and [sO].[sID] <= 10686
order by [sO].[sID]

Answer 1

您可以使用 CROSS APPLY 而不是 JOIN 来做您想做的事情:

select top 10 [docSVsys].[sID], [sI].[count] 
from docSVsys  
cross apply 
( 
    select count(*) as [count]    
    from docSVenum1 as [sIt] 
    where  [sIt].[sID] = [docSVsys].[sID]  
) as [sI]  
order by [docSVsys].[sID]