如何GROUP BY由CASE語句返回的子查詢值

Question

我一直在努力尋找答案。這是我維護的代碼，沒有錯誤。它位於爲報表返回數據的存儲過程中。

爲了便於閱讀，我將它縮小了，只是包含了必要的部分。

它的工作原理沒有錯誤，但已經提出了一個請求，使其將相應行中的所有相關數據分組。

主要問題是應用GROUP BY語句包含一個子查詢的第三個CASE語句：

SELECT 
      CompanyName, 
      CompanyRef, 
      Amount, 
      Reference, 
      VendorNo, 
      CASE ErrorID WHEN 10 'Company Name: ' + CompanyName + 'CompanyRef' END AS InvalidCompanyNameForRef, 
      CASE ErrorID WHEN 11 'Vendor Number:' + VendorNo END AS InvalidVendorNo, 
      CASE ErrorID WHEN 12 (SELECT TOP(1) 'Non VAT Amount:' + CAST(PendingPayments.NonVatAmount AS varchar) + 'Import Amount:' + CAST(Imported.PaymentAmount) FROM PendingPayments 
         WHERE Imported.CompanyRef = PendingPayments.CompanyRef 
          AND Imported.VendorNo = PendingPayments.VendorNo 
           AND ISNUMERIC(Imported.PaymentAmount) = 1 
          AND CAST(Imported.PaymentAmount AS MONEY) <> PendingPayments.NonVatAmount AND PendingPayments.isVAT = 0  
         ) END As PaymentAmountMismatch 
     . 
     . 
     . 
GROUP BY 
      CompanyName, 
      CompanyRef, 
      Amount, 
      Reference, 
      VendorNo, 
      CASE ErrorID WHEN 10 'Company Name: ' + CompanyName + 'CompanyRef' END, 
      CASE ErrorID WHEN 11 'Vendor Number:' + VendorNo END 

如何使IT部門從SUBQUERY衍生領域。

，而不是返回相同數據的不同列不同行的，我想這回是這樣的：

CompanyName | CompanyRef | Amount | Reference | VendorNo | InvalidCompanyNameForRef  | Invalid Vendor Number | PaymentAmountMismatch 
------------+------------+--------+-----------+----------+------------------------------+-----------------------+-----------------------------------------+ 
ABC   | 1   | 25.00 | INV001 |390  |Company Name: ABC CompanyRef:1|      | 
DEF   | 5   | 12.00 | INV002 |212  |        |     212 |Expected Amount:12.50, Import Amount:12.00 
HIJ   | 7   | 9.50 | INV003 |31  |Company Name: HIJ CompanyRef:7|      | 

Answer 1

在我看來，CTE can help you。代碼沒有經過測試，但我認爲這足以讓人想到。

WITH cte 
      (CompanyName, 
      CompanyRef, 
      Amount, 
      Reference, 
      VendorNo, 
      InvalidCompanyNameForRef, 
      InvalidVendorNo, 
      PaymentAmountMismatch) AS 
(
SELECT 
CompanyName, 
CompanyRef, 
Amount, 
Reference, 
VendorNo, 
CASE ErrorID WHEN 10 'Company Name: ' + CompanyName + 'CompanyRef' END AS InvalidCompanyNameForRef, 
CASE ErrorID WHEN 11 'Vendor Number:' + VendorNo END AS InvalidVendorNo, 
CASE ErrorID WHEN 12 (SELECT TOP(1) 'Non VAT Amount:' + CAST(PendingPayments.NonVatAmount AS varchar) + 'Import Amount:' + CAST(Imported.PaymentAmount) FROM PendingPayments 
      WHERE Imported.CompanyRef = PendingPayments.CompanyRef 
       AND Imported.VendorNo = PendingPayments.VendorNo 
        AND ISNUMERIC(Imported.PaymentAmount) = 1 
       AND CAST(Imported.PaymentAmount AS MONEY) <> PendingPayments.NonVatAmount AND PendingPayments.isVAT = 0  
       ) END As PaymentAmountMismatch 
) 
SELECT * FROM cte 
GROUP BY 
    CompanyName, 
    CompanyRef, 
    Amount, 
    Reference, 
    VendorNo, 
    InvalidCompanyNameForRef, 
    InvalidVendorNo, 
    PaymentAmountMismatch