在查询中包含CTE

Question

我有下面的代码，它完美地工作。

我需要做的是将它包含在查询中，使用CTE的结果作为查询结果中的一列，但我无法找到包含它的方式。 有什么想法吗？

我想实际上是这样的：

select a, 
b, 
c, 
d, 

WITH invoicedates AS (
    SELECT 
     ROW_NUMBER() OVER (ORDER BY Inv_Date DESC) AS RowNumber, 
     inv_Date, INVIT_PARTNO 
    FROM Invoices join InvoiceItems on invit_invno = inv_no 
    WHERE invit_partno = stock_no and inv_canind <> 'Y' and inv_date >= DATEADD(yy, -1, getdate()) 
) 
SELECT 
    AVG(DATEDIFF(DD, O2.Inv_Date, O1.Inv_Date)) AS AverageFrequency 
FROM invoicedates O1 
LEFT JOIN invoicedates O2 
    ON O2.RowNumber = O1.RowNumber + 1 

从股票那里..........

给予产生ABCD结果的输出

Answer 1

你应该能够重新排序你如何使用CTE：

; WITH invoicedates (RowNumber, inv_Date, INVIT_PARTNO) AS (
    SELECT 
     ROW_NUMBER() OVER (ORDER BY Inv_Date DESC) AS RowNumber, 
     inv_Date, INVIT_PARTNO 
    FROM Invoices join InvoiceItems on invit_invno = inv_no 
    WHERE invit_partno = stock_no and inv_canind <> 'Y' and inv_date >= DATEADD(yy, -1, getdate()) 
) 

select a, 
b, 
c, 
d, 
    AVG(DATEDIFF(DD, O2.Inv_Date, O1.Inv_Date)) AS AverageFrequency 
FROM invoicedates O1 
LEFT JOIN invoicedates O2 
    ON O2.RowNumber = O1.RowNumber + 1