加入這些表時為什么會出現錯誤？

Question

我正在嘗試加入這兩個表，但我收到錯誤代碼？

SELECT LoanNumber, LetterDescription, LetterID, LetterDate, LetterProcessingDate
FROM PortfolioData.dbo.LetterData L
WHERE LetterID IN ('DF013', 'LM002')
LEFT JOIN MainServicing
ON Letterdata.LoanNumber = MainServicing.Loannumber

SELECT Loannumber,Lo_TypeDesc,Inv_ID,Investor_Desc,NPDD,UPB,cast(Date_Archived as date) as Date_Archived
FROM PortfolioData.dbo.MainServicing
WHERE Lo_TypeDesc IN ('USDA RHS') OR Investor_Desc IN ('FNMA','FHLMC')
AND (DATEDIFF(day,LetterDate,Date_Archived)<30)
 

Answer 1

SELECT L.LoanNumber, L.LetterDescription, L.LetterID, L.LetterDate, LetterProcessingDate
FROM PortfolioData.dbo.LetterData L  <---- Alias Here
WHERE LetterID IN ('DF013', 'LM002')
LEFT JOIN MainServicing M <---- Alias Here (Add it)
ON L.LoanNumber = M.Loannumber

您在 from 語句中有別名，請嘗試在 LoanNumber 上使用別名 L 以及特定於 select 語句的其他字段。 我也會考慮添加 M 或一些別名。 請注意，您有 LoanNumber 看起來它位於兩個表中，因此您需要對其進行限定，以便 select 知道 go 到哪個表。