嵌套的SQL左联接与数据透视和取消透视

Question

SELECT [Table], Facility_Code,
   ISNULL([1],0) AS [1],
   ISNULL([2],0) AS [2],
   ISNULL([3],0) AS [3],
   ISNULL([4],0) AS [4],
   ISNULL([5],0) AS [5],
   ISNULL([6],0) AS [6],
   ISNULL([7],0) AS [7],
   ISNULL([8],0) AS [8],
   ISNULL([9],0) AS [9],
   ISNULL([10],0) AS [10],
   ISNULL([11],0) AS [11],
   ISNULL([12],0) AS [12],
FROM(
    SELECT 'TotalItemsProduced' AS [Table],
    L.Facility_Code,
    [Month],
    Total_Item_Count
FROM production L
LEFT JOIN(
    SELECT
         Facility_Code,
         COUNT(DISTINCT(item_nbr)) AS Total_Item_Count,
         MONTH(datetime) AS MONTH
    FROM item
    WHERE YEAR(datetime) = 2018
    GROUP BY Facility_Code, MONTH(datetime)
 )R
 ON L.Facility_Code = R.Facility_Code
)T
PIVOT(MAX(Total_Item_Count) FOR [Month] IN ([1], [2], [3], [4], [5], [6], 
[7], [8], [9], [10], [11], [12])) AS PVT

我写了这段代码，到此为止，现在我必须取消透视表。我不确定如何嵌套在unpivot函数中，因为左联接有点让我失望。