Question

在下面的SQL中，如果select无法在查找表中找到值，则Bank列将返回一个emty字符串（＆＃39;＆＃39;）。我想在字段b.BankName

中显示值，而不是空字符串

SELECT 
' ' AS DUMMY, 
c.CustomerNumber AS DirectDebitRef,
(SELECT replace(bankname, 'Other (please specify)', '')
 FROM Banks
 WHERE bankid = b.bankid) AS Bank, 
b.SortCode AS SortCode
FROM 
dbo.Customers AS c 
INNER JOIN dbo.CustomerBanks AS b ON c.CustomerBankId = b.CustomerBankId
INNER JOIN dbo.View_CustomerBillingsToday AS v ON c.CustomerId = v.CustomerId 
INNER JOIN dbo.CustomerAddressBillings AS s ON c.CustomerAddressBillingId = s.CustomerAddressBillingId

我添加b.BankName的那一刻，我在所有具有有效查找的行中获得NULL输出。如果我用'＆＃39; x＆＃39;替换b.BankName我得到了所有行的值。所以我知道替换工作，但是当我尝试引用有效的fieldname时，它会使所有其他行为空

replace( (SELECT        bankname
                               FROM            Banks
                               WHERE        bankid = b.bankid), 'Other (please specify)', b.BankName) AS Bank

Answer 1

案例陈述有效，使用它而非替换做了诀窍： - ）

 case WHEN (SELECT bankname
                               FROM            Banks
                               WHERE        bankid = b.bankid) = 'Other (Please Specify)' THEN b.BankName
                               ELSE (SELECT bankname
                               FROM            Banks
                               WHERE        bankid = b.bankid)
                               END AS Bank

使用来自2个位置的值填充列

1 个答案: