Question

因此，以下Windows函数可以获取计算列：

USE MfgMetrics 
SELECT
[Calc_ORDER_NUMBER_LAG] = LAG([ORDER NUMBER],1,0) OVER (Order By [ORDER NUMBER],[FileDate]),
[Calc_Order_Quantity_LAG] = LAG([Order_Quantity],1,0) OVER (Order By [ORDER NUMBER], [FileDate]),
[Calc_Qty_Changed] = 
       (
       CASE 
       WHEN [ORDER NUMBER]!=LAG([ORDER NUMBER],1,0) OVER (Order By [ORDER NUMBER],[FileDate]) THEN 2
       WHEN [ORDER NUMBER]=LAG([ORDER NUMBER],1,0) OVER (Order By [ORDER NUMBER],[FileDate])
             AND [ORDER NUMBER]!=LAG([ORDER NUMBER],1,0) OVER (Order By [ORDER NUMBER],[FileDate]) 
             AND [Order_Quantity] != LAG([Order_Quantity],1,0) OVER (Order By [ORDER NUMBER], [FileDate]) 
             AND [ACTUAL START DATE] != 0 AND [FileDate] >= [ACTUAL START DATE] 
       THEN 1 
       ELSE 0 
       END
       ) 
FROM dbo.Testing_Table_II

但是我需要将计算的列添加到Testing_Table_II，当我尝试这个时：

USE MfgMetrics 
ALTER TABLE dbo.Testing_Table_II
SELECT
ADD [Calc_ORDER_NUMBER_LAG] AS LAG([ORDER NUMBER],1,0) OVER (Order By [ORDER NUMBER],[FileDate]),
ADD [Calc_Order_Quantity_LAG] AS LAG([Order_Quantity],1,0) OVER (Order By [ORDER NUMBER], [FileDate]),
ADD [Calc_Qty_Changed] AS
       (
       CASE 
       WHEN [ORDER NUMBER]!=LAG([ORDER NUMBER],1,0) OVER (Order By [ORDER NUMBER],[FileDate]) THEN 2
       WHEN [ORDER NUMBER]=LAG([ORDER NUMBER],1,0) OVER (Order By [ORDER NUMBER],[FileDate])
             AND [ORDER NUMBER]!=LAG([ORDER NUMBER],1,0) OVER (Order By [ORDER NUMBER],[FileDate]) 
             AND [Order_Quantity] != LAG([Order_Quantity],1,0) OVER (Order By [ORDER NUMBER], [FileDate]) 
             AND [ACTUAL START DATE] != 0 AND [FileDate] >= [ACTUAL START DATE] 
       THEN 1 
       ELSE 0 
       END
       ) 
FROM dbo.Testing_Table_II

它不起作用...当Windows函数必须在SELECT FROM中时，我不确定如何进行alter或create列。

任何帮助表示赞赏！我对这些东西真的很陌生，所以我可能会感到很小（愚蠢）。提前谢谢！

Answer 1

您需要先更改表格，然后将选择作为更新运行，并加入字段键。

ALTER Testing_Table_II ADD 
    Calc_ORDER_NUMBER_LAG AS INT,
    Calc_Order_Quantity_LAG AS INT,
    Calc_Qty_Changed AS INT

GO

UPDATE
    TT
SET
    TT.Calc_ORDER_NUMBER_LAG= TT2.Calc_ORDER_NUMBER_LAG,
    TT.Calc_Order_Quantity_LAG= TT2.Calc_Order_Quantity_LAG
   ...
FROM
    Testing_Table_II AS TT
    INNER JOIN 
    (
       <PASTE YOUR FIRST QUERY HERE>
    ) 
    AS TT2 ON TT.PrimaryKey = TT2.PrimaryKey

SQL将Windows函数添加为新列

1 个答案: