如何將max（number）條件放入SQL Server 2008中的where子句

Question

我的查詢是：

Select 
    res.*, s.Description as GroupSpecialty, 
    MAX(CASE WHEN Period = @Q9 THEN cases END) OVER (PARTITION BY Group,Zone) as CompletedVolume 
from 
    res

我需要做的是消除CompletedVolume <50時的所有數據。

當我where CompletedVolume >= 50寫時，它說沒有列作為CompletedVolume 。 當我寫MAX(CASE WHEN Period = @Q9 THEN cases END) OVER (PARTITION BY Group, Zone) >= 50 ，它說

窗口函數只能出現在SELECT或ORDER BY子句中

因此，我無法提供此條件。 我怎樣才能做到這一點？ 謝謝。

Answer 1

使用查詢作為派生表

SELECT *
FROM 
  (select res.*, s.Description as GroupSpecialty, 
  MAX(CASE WHEN Period=@Q9 THEN cases END) OVER (PARTITION BY Group,Zone) as CompletedVolume 
  from res) DerivedTable
WHERE CompletedVolume < 50

或CTE

;WITH cte
AS
(
select res.*, s.Description as GroupSpecialty, 
MAX(CASE WHEN Period=@Q9 THEN cases END) OVER (PARTITION BY Group,Zone) as CompletedVolume 
from res
)

SELECT * from cte
where completedvolume < 50