Question

当我运行以下查询时，发生错误：

为变量赋值的SELECT语句不能是结合数据检索操作。

我该如何解决这个问题？

以下是查询：

DECLARE @loanInstallmet float

SELECT TOP (1) 
    loan.loanID,members.offno AS OfficialNumber,
    loan.loanAmount,
    loan.interestRate,
    loan.NoOfInstallment,
    loanHistory.presentInstallmentNo,
    loanHistory.dateBalanceUpdate,
    (loanHistory.presentInstallmentNo + 1) AS InstallmentNo, 
    members.monthllyContribution AS MonthlyContribution, 
    @loanInstallmet = 
        CASE 
            WHEN  loan.remarks = 'Half' THEN ROUND(loanHistory.balanceAmount/ (loan.NoOfInstallment-loanHistory.presentInstallmentNo ), 0) 
            ELSE ROUND((loan.loanAmount / loan.NoOfInstallment), 0)
        END, 
    CASE 
        WHEN  loanHistory.presentInstallmentNo % 12 = 0 THEN ROUND(((loan.loanAmount-loanHistory.balanceAmount) * loan.interestRate / 1200), 0)
        ELSE ROUND((loan.loanAmount * loan.interestRate / 1200), 0)
    END AS MonthlyInterest, 
    LEFT(DATENAME(MONTH,Getdate()),3)as recMonth,
    year(GETDATE())as recYear,
    loan.isRecovered as LoanIsRecovered,
    members.memberIsActive,
    loanHistory.status,
    ROUND((loanHistory.balanceAmount-@loanInstallmet), 0) AS BalanceAmount,
    loan.remarks
FROM loan
INNER JOIN members 
    ON loan.offNo = members.offno
INNER JOIN loanHistory 
    ON members.offno = loanHistory.offNo
    AND loan.loanID = loanHistory.loanID
WHERE 
    loan.isRecovered = 0
    AND members.memberIsActive = 1  
order by loanHistory.presentInstallmentNo DESC

Answer 1

这是说它意味着什么！ ;）

你无法做到：

SELECT TOP（1）loan.loanID，members.offno AS OfficialNumber，....

同时：

SELECT @loanInstallmet =例如，当loan.remarks =＆＃39; Half＆＃39;那么

您要么为应用程序检索数据，要么设置变量的值。同时做两者并不符合逻辑。

如果您想计算@loanInstallmet并在将来的计算中使用它，您可以执行以下操作：

x.indexOf("foo") > -1 //true

tblLoanInstallCalc是一个公用表表达式（CTE），在您尝试累加余额之前预先计算先决条件

Answer 2

将SELECT语句中的列值分配给局部变量时会发生此错误，但并非所有列都分配给相应的局部变量。
要避免此错误，请确保将所有列分配给局部变量。

如果您确实需要同时执行这两个操作，意味着将值分配给局部变量并将列作为结果集返回，则必须分两步执行，而不是将它们组合到一个SELECT语句中：

DECLARE @CompanyName NVARCHAR(40)
DECLARE @ContactName NVARCHAR(30)

SELECT @CompanyName = [CompanyName],
       @ContactName = [ContactName],
FROM [dbo].[Customers]
WHERE [CustomerID] = 'ALFKI'

SELECT [ContactTitle]
FROM [dbo].[Customers]
WHERE [CustomerID] = 'ALFKI'

请阅读此article了解详情

错误：为变量赋值的SELECT语句不能与数据检索操作结合使用

2 个答案: