如何獲取此查詢中的實際運行餘額

Question

繼我從昨天最初提出的問題(here)後，我能夠構建下面的SQL查詢，該查詢生成了運行的發票和付款清單。

SELECT 
    'Invoice' AS TransactionType, 
    i.InvoiceNumber AS Description, 
    i.InvoiceDate AS TransactionDate, 
    CAST(ROUND(i.OutstandingBalance, 2) AS DECIMAL(12, 2)) AS TransactionAmount 
FROM 
    Invoices i 
WHERE 
    i.CustomerId = 12 
    AND i.InvoiceDate BETWEEN '20150601' AND '20160229' 
    AND i.OutstandingBalance > 0.02 

UNION 

SELECT 
    'Payment' AS TransactionType, 
    ip.InvoicePaymentId AS Description, 
    ip.InvoicePaymentDate AS TransactionDate, 
    - ip.Amount AS TransactionAmount 
FROM 
    InvoicePayments ip 
WHERE 
    ip.CustomerId = 12 
    AND ip.InvoicePaymentDate BETWEEN '20150601' AND '20160229' 
ORDER BY 
    TransactionDate 

我現在想要做的是產生一個額外的列，它實際上是帳戶上的運行餘額。我想，如果我開始使用一個變量，那麼應該可以添加（或從中減去給我的東西）。爲此，我嘗試了以下內容;

DECLARE @OutstandingBalance MONEY = 0 

SELECT 
    'Invoice' AS TransactionType, i.InvoiceNumber AS Description, 
    i.InvoiceDate AS TransactionDate, 
    CAST(ROUND(i.OutstandingBalance, 2) AS DECIMAL(12, 2)) AS TransactionAmount, 
    @OutstandingBalance + CAST(ROUND(i.OutstandingBalance, 2) AS DECIMAL(12, 2)) AS Balance 
FROM 
    Invoices i 
WHERE 
    i.CustomerId = 12 
    AND i.InvoiceDate BETWEEN '20150601' AND '20160229' 
    AND i.OutstandingBalance > 0.02 

哪產生了下面的結果。

但是試圖通過使它@OutstandingBalance + =像這樣修改的查詢;

DECLARE @OutstandingBalance MONEY = 0 

SELECT 
    'Invoice' AS TransactionType, i.InvoiceNumber AS Description, 
    i.InvoiceDate AS TransactionDate, 
    CAST(ROUND(i.OutstandingBalance, 2) AS DECIMAL(12, 2)) AS TransactionAmount, 
    @OutstandingBalance += CAST(ROUND(i.OutstandingBalance, 2)AS DECIMAL(12,2)) AS Balance 
FROM 
    Invoices i 
WHERE 
    i.CustomerId = 12 
    AND i.InvoiceDate BETWEEN '20150601' AND '20160229' 
    AND i.OutstandingBalance > 0.02 

拋出一個錯誤告訴我，語法附近關鍵字AS（這我相信所指的平衡不正確。我懷疑，我應該是「設置」的@OutstandingBalance價值，但加入中的一組語句選擇也會引發錯誤。

是否有可能在這種查詢的創建運行平衡，如果是一個人如何適應設置@OutstandingBalance實現呢？

針對低於這個答案是結果集我得到：

編輯 修訂查詢以適應發票和付款：

SELECT 'Invoice' AS TransactionType, 
     i.InvoiceNumber AS Description, 
     i.InvoiceDate AS TransactionDate, 
     CAST(ROUND(i.OutstandingBalance,2)AS DECIMAL(12,2)) AS TransactionAmount , 
     SUM(CAST(ROUND(i.OutstandingBalance,2)AS DECIMAL(12,2))) OVER(ORDER BY i.InvoiceDate, i.InvoiceNumber) AS Balance 
FROM Invoices i 
WHERE i.CustomerId = 12 
AND i.InvoiceDate BETWEEN '20150601' AND '20160229' 
AND i.OutstandingBalance > 0.02 

UNION 

    SELECT 
    'Payment' AS TransactionType, 
    ip.InvoicePaymentId AS Description, 
    ip.InvoicePaymentDate AS TransactionDate, 
    - ip.Amount AS TransactionAmount, 
    SUM(CAST(ROUND(-ip.Amount,2) AS DECIMAL(12,2))) OVER(ORDER BY ip.InvoicePaymentDate,ip.InvoicePaymentId) AS Balance 

    FROM InvoicePayments ip 
    WHERE ip.CustomerId = 12 
    AND ip.InvoicePaymentDate BETWEEN '20150601' AND '20160229' 



ORDER BY TransactionDate, Description 

將會產生如下：

Answer 1

您可以使用SUM像這樣的OVER條款：

SELECT 'Invoice' AS TransactionType, 
     i.InvoiceNumber AS Description, 
     i.InvoiceDate AS TransactionDate, 
     CAST(ROUND(i.OutstandingBalance,2)AS DECIMAL(12,2)) AS TransactionAmount , 
     SUM(CAST(ROUND(i.OutstandingBalance,2)AS DECIMAL(12,2))) OVER(ORDER BY i.InvoiceDate, i.InvoiceNumber) AS Balance 
FROM Invoices i 
WHERE i.CustomerId = 12 
AND i.InvoiceDate BETWEEN '20150601' AND '20160229' 
AND i.OutstandingBalance > 0.02 
ORDER BY TransactionDate, Description 

你也可以使用一個CTE來保存一個投：

;WITH cte AS 
(
SELECT 'Invoice' AS TransactionType, 
     i.InvoiceNumber AS Description, 
     i.InvoiceDate AS TransactionDate, 
     CAST(ROUND(i.OutstandingBalance,2)AS DECIMAL(12,2)) AS TransactionAmount 
FROM Invoices i 
WHERE i.CustomerId = 12 
AND i.InvoiceDate BETWEEN '20150601' AND '20160229' 
AND i.OutstandingBalance > 0.02 
) 

SELECT TransactionType, 
     Description, 
     TransactionDate, 
     TransactionAmount, 
     SUM(TransactionAmount) OVER(ORDER BY TransactionDate, Description) AS Balance 
FROM cte 
ORDER BY TransactionDate, Description