SQL-根據YTD編號計算得出的MTD編號

Question

我們有一個YTD報告，該報告每月運行一次。 我想通過計算Month + 1減去Month0 = MTD來計算每個月的MTD運動

下表中的數據如下

Month | Account | YTD amount
Jan   | AB123   | 100
Feb   | AB123   | 200
Mar   | AB123   | 350

我有許多帳戶，需要運行如下所示的MTD。

Month | Account | MTD Amount
Jan   | AB123   | 100
Feb   | AB123   | 100
Mar   | AB123   | 150

我讀過您可以做一個自我聯接，可以在同一張表中搜索另一行。 但是，如果您有超過3個月的時間，我無法完全理解如何多次執行此操作。 一月和二月看起來直截了當。

SELECT A.[Month]
  ,A.[Account]
  ,A.[YTD] FebYTD
  ,B.[YTD] JanYTD
  ,A.[YTD] - B.[YTD] MTD
FROM 
(
SELECT [Month]
   ,[Account]
   ,[YTD]
FROM [PWC_2017].[dbo].[MTD test]
where [Month] = 'Feb'
) A
join
(
SELECT [Month]
  ,[Account]
  ,[YTD]
FROM [PWC_2017].[dbo].[MTD test]
Where [Month] = 'Jan'
) B
on A.[Account] = B.[Account]

結果如下

Month | Account | FebYTD | JanYTD | MTD
Feb   | AB123   |   200  |  100   | 100

我想做一個查詢，每個月可以運行一次。 因此，例如，當9月一個月來臨時，它將給我9行MTD。 1月-9月。 基本上，它將在當前時間表中可用的所有月份上運行。 謝謝。

Answer 1

上述內容的一個小補充。

基於與YTD-1進行比較的前提，並包括了MTD的情況，盡管示例中解決了1月的問題，但例如僅在3月左右記錄數據時，它是行不通的。 第一個MTD將為NULL。

所以我簡單地講，當以前的YTD不存在時，添加一個零，

CASE CurrentYTD.Month_ID
WHEN 1 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0) 
WHEN 2 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 3 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 4 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 5 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 6 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 7 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 8 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 9 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 10 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 11 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
WHEN 12 Then COALESCE (CurrentYTD.Amount,PreviousYTD.Amount)- COALESCE(PreviousYTD.Amount,0)
END AS Amount_MTD

Answer 2

您可以嘗試以下查詢

SELECT Current.[Month], 
       Current.[Account], 
       Current.[YTD]                                       CurrentYTD, 
       Next.[YTD]                                          NextYTD, 
       COALESCE(Next.[YTD], Current.[YTD]) - Current.[YTD] MTD 
FROM   (SELECT [Month], 
               CASE [Month] 
                 WHEN 'Jan' THEN 1 
                 WHEN 'Feb' THEN 2 
                 WHEN 'Mar' THEN 3 
                 WHEN 'Apr' THEN 4 
                 WHEN 'May' THEN 5 
                 WHEN 'June' THEN 6 
                 WHEN 'July' THEN 7 
                 WHEN 'Aug' THEN 8 
                 WHEN 'Sept' THEN 9 
                 WHEN 'Oct' THEN 10 
                 WHEN 'Nov' THEN 11 
                 WHEN 'Dec' THEN 12 
               END AS [MonthId], 
               [Account], 
               [YTD] 
        FROM   [PWC_2017].[dbo].[MTD test]) Current 
       LEFT JOIN (SELECT [Month], 
                         CASE [Month] 
                           WHEN 'Jan' THEN 1 
                           WHEN 'Feb' THEN 2 
                           WHEN 'Mar' THEN 3 
                           WHEN 'Apr' THEN 4 
                           WHEN 'May' THEN 5 
                           WHEN 'June' THEN 6 
                           WHEN 'July' THEN 7 
                           WHEN 'Aug' THEN 8 
                           WHEN 'Sept' THEN 9 
                           WHEN 'Oct' THEN 10 
                           WHEN 'Nov' THEN 11 
                           WHEN 'Dec' THEN 12 
                         END AS [MonthId], 
                         [Account], 
                         [YTD] 
                  FROM   [PWC_2017].[dbo].[MTD test]) Next 
              ON Current.[Account] = Next.[Account] 
                 And Current.[MonthId] + 1 = Next.[MonthId]