如何按SQL SELECT語句中的特定列計數記錄並將該值放在該行的另一列中

Question

我正在嘗試為同一學生的AppNum列中放入一個計數值，其中結果集中的FIRST / TOP記錄為1，隨后的記錄為2、3，依此類推。我嘗試使用GROUP BY而不是得到我想要的結果。 在下面的PIC中，第一個結果集顯示了我所得到的，第二個結果集是我所需要的。

這是我要做什么的圖片：

我嘗試獲取正確結果集的查詢如下。 任何幫助/方向將不勝感激：

SELECT 
    StudentID, Location, Status, EconomicDisadvantageCode, 
    StatusEffectiveDate, Enddate, SchoolYear, ApplicationTypeCode, 
    LastUpdated, UpdatedAppType, DataSource, COUNT(Status) AS AppNum
FROM 
    #MCS_5
WHERE 
    StudentID IN (SELECT StudentID 
                  FROM #MCS_5 
                  GROUP BY StudentID 
                  HAVING COUNT(StudentID) > 1)
GROUP BY 
    Status, StudentID, Location, Status, EconomicDisadvantageCode, 
    StatusEffectiveDate, Enddate, SchoolYear, ApplicationTypeCode, 
    LastUpdated, UpdatedAppType, DataSource
ORDER BY 
    StudentID ASC, StatusEffectiveDate ASC;

Answer 1

使用row_number函數，在這種情況下非常方便。

SELECT StudentID
    ,Location
    ,STATUS
    ,EconomicDisadvantageCode
    ,StatusEffectiveDate
    ,Enddate
    ,SchoolYear
    ,ApplicationTypeCode
    ,LastUpdated
    ,UpdatedAppType
    ,DataSource
    ,ROW_NUMBER () OVER (PARTITION BY Studentid,STATUS ORDER BY [STATUS]) 
     Appnum
FROM #MCS_5
WHERE StudentID IN (
        SELECT StudentID
        FROM #MCS_5
        GROUP BY StudentID
        HAVING COUNT(StudentID) > 1
        )

Answer 2

只需對所有功能使用窗口函數：

Select ...
From (select t.*,
             Row_number() over (partition by studentid order by status) as seqnum,
             Count(*) over (partition by studentid) as cnt
      From #mcd_5 t
     ) t
Where cnt > 1