用MS Access SQL中的文本或0替换NULL

Question

我有一个数据库，该数据库可跟踪组织零件清单中的贷款和投资回收期。它们是单独的表DiversionT和PaybackT。我也有包含客户和零件信息的表CustomerT和PartsT。我有一个查询（包含两个子查询），其目标是从表单中获取客户和零件，并让一个子查询计算给定零件和给定客户的贷款总和。

FROM PartsT INNER JOIN (CustomerT INNER JOIN DiversionT ON CustomerT.CustomerID = DiversionT.CustomerID) ON PartsT.PartID = DiversionT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]));

另一个子查询求和相同客户和零件的投资回报。

SELECT CustomerT.CustomerProgram,PartsT.PartID,Sum(PaybackT.PayAmountParts) AS SumOfPayAmountParts
FROM PartsT INNER JOIN (CustomerT INNER JOIN PaybackT ON CustomerT.CustomerID = PaybackT.CustomerID) ON PartsT.PartID = PaybackT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]));

然后将这些结果进行求差，以得到所欠的余额，然后通过Excel呈现以进行导出：

FROM SinglePartSumQ, CustomerT, SinglePartPaybackSumQ INNER JOIN PartsT ON SinglePartPaybackSumQ.PartID = PartsT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID, PartsT.IndiaUID, PartsT.NSN, PartsT.PartName, SinglePartSumQ.SumOfRcvdQTY, SinglePartPaybackSumQ.SumOfPayAmountParts
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]))
ORDER BY CustomerT.CustomerProgram;

对于同时位于DiversionT和PaybackT中的项目，查询工作正常，但是在可能未发生任何回收的情况下，我希望第二个子查询返回客户，零件ID和总和的0。现在，第二个子查询返回空白，因此最终的差异查询不起作用。

我已经尝试在我的投资回报总额查询中使用ISNULL函数，其中对于客户和零件，如果为null，我希望它返回名称和零件ID，然后当总和始终为null时，则返回0，这样差分操作将使用0。

我已经尝试了以下ISNULL的实现来实现投资回报总额查询：

SELECT ISNULL(CustomerT.CustomerProgram,CustomerT.CustomerProgram), ISNULL(PartsT.PartID,PartsT.PartID), ISNULL(Sum(PaybackT.PayAmountParts),0) AS SumOfPayAmountParts
FROM PartsT INNER JOIN (CustomerT INNER JOIN PaybackT ON CustomerT.CustomerID = PaybackT.CustomerID) ON PartsT.PartID = PaybackT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]));

但是我遇到运行时错误'3326'：此记录集不可更新。当我尝试调试时，将带我进入以下格式的VBA代码：

Option Compare Database

Private Sub AllPartSearch_Click()
End Sub

Private Sub OnePartOneCust_Click()
Dim getFolder As Object
Dim sLoc As String
Dim fileN As String
DoCmd.OpenQuery "SinglePartSumQ"
DoCmd.OpenQuery "SinglePartPaybackSumQ"
DoCmd.OpenQuery "OneCustOnePartQ"
Set getFolder = Application.FileDialog(msoFileDialogFolderPicker)
With getFolder
    .AllowMultiSelect = False
    fileN = Forms!PartsSearchF!FileName
    If .Show = True Then
        sLoc = getFolder.SelectedItems(1) & "\"
    End If
End With
DoCmd.TransferSpreadsheet acExport, , "OneCustOnePartQ", sLoc & fileN & ".xlsx", True
End Sub

Private Sub PartSearch_Click()
End Sub

调试器将第二个DoCmD.OpenQuery语句标记为投资回报查询，当我运行调试器时，得到运行时错误'3075'：查询表达式'ISNULL（CustomerT.CustomerProgram）中的函数使用的参数数量错误，CustomerT.CustomerProgram'。

首先可以做我想做的事吗？第二，我的ISNULL实现有什么问题？

更新：我已将ISNULL更改为NZ。当我使用在PaybackT中没有任何条目的零件时，投资回报查询返回三列Expr1，Expr2，SumofPayAmountParts，其中没有任何内容。另外，无论PaybackT中的状态如何，查询都会打开一个参数窗口以查找输入，但是它应该从所需的表单中获取所有内容，例如NZ或ISNULL不在时？这是我现在用于回报查询的代码：

SELECT Nz(CustomerT.CustomerProgram,CustomerT.CustomerProgram) AS Expr1, Nz(PartsT.PartID,PartsT.PartID) AS Expr2, Nz(Sum(PaybackT.PayAmountParts),0) AS SumOfPayAmountParts
FROM PartsT INNER JOIN (CustomerT INNER JOIN PaybackT ON CustomerT.CustomerID = PaybackT.CustomerID) ON PartsT.PartID = PaybackT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]));

这是差异查询的代码；

SELECT NZ(CustomerT.CustomerProgram,CustomerT.CustomerProgram), NZ(PartsT.PartID,PartsT.PartID),NZ(PartsT.IndiaUID, PartsT.IndiaUID),NZ(PartsT.NSN,PartsT.NSN), NZ(PartsT.PartName,PartsT.PartName), NZ(SinglePartSumQ.SumOfRcvdQTY,SinglePartSumQ.SumOfRcvdQTY), NZ(SinglePartPaybackSumQ.SumOfPayAmountParts),SinglePartPaybackSumQ.SumOfPayAmountParts, SinglePartSumQ.SumOfRcvdQTY-SinglePartPaybackSumQ.SumOfPayAmountParts AS BalanceOwed
FROM SinglePartSumQ, CustomerT, SinglePartPaybackSumQ INNER JOIN PartsT ON SinglePartPaybackSumQ.PartID = PartsT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID, PartsT.IndiaUID, PartsT.NSN, PartsT.PartName, SinglePartSumQ.SumOfRcvdQTY, SinglePartPaybackSumQ.SumOfPayAmountParts
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]))
ORDER BY CustomerT.CustomerProgram;

更新2：基于一些费用返还，我已经更新了我的代码，所有列标题现在都显示在所有三个查询中，但是投资回收期和差异查询仍然显示为空白。

这里是转移总和查询：

SELECT CustomerT.CustomerProgram, PartsT.PartID, Sum(Nz(DiversionT.RcvdQTY,0)) AS SumOfRcvdQTY
FROM PartsT INNER JOIN (CustomerT INNER JOIN DiversionT ON CustomerT.CustomerID = DiversionT.CustomerID) ON PartsT.PartID = DiversionT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]));

回收期总和查询

SELECT CustomerT.CustomerProgram, PartsT.PartID, Sum(NZ((PaybackT.PayAmountParts),0)) AS SumOfPayAmountParts
FROM PartsT INNER JOIN (CustomerT INNER JOIN PaybackT ON CustomerT.CustomerID = PaybackT.CustomerID) ON PartsT.PartID = PaybackT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]));

和差异查询

SELECT CustomerT.CustomerProgram, PartsT.PartID,PartsT.IndiaUID,PartsT.NSN,PartsT.PartName,SinglePartSumQ.SumOfRcvdQTY, SinglePartPaybackSumQ.SumOfPayAmountParts, NZ(SinglePartSumQ.SumOfRcvdQTY,0)-NZ(SinglePartPaybackSumQ.SumOfPayAmountParts,0) AS BalanceOwed
FROM SinglePartSumQ, CustomerT, SinglePartPaybackSumQ INNER JOIN PartsT ON SinglePartPaybackSumQ.PartID = PartsT.PartID
GROUP BY CustomerT.CustomerProgram, PartsT.PartID, PartsT.IndiaUID, PartsT.NSN, PartsT.PartName, SinglePartSumQ.SumOfRcvdQTY, SinglePartPaybackSumQ.SumOfPayAmountParts
HAVING (((CustomerT.CustomerProgram)=[Forms]![PartsSearchF]![CustomerSearch]) AND ((PartsT.PartID)=[Forms]![PartsSearchF]![PartSearch]))
ORDER BY CustomerT.CustomerProgram;

我感觉问题在于Access生成的inner join语句以及它如何寻找比较。由于Diversion表永远不会有空条件，因为如果我基于Diversion的差异表中显示的内容，就不会查看是否未借出零件。即在差异查询中修复此行（我只是不知道如何成为SQL新手）：FROM SinglePartSumQ, CustomerT, SinglePartPaybackSumQ INNER JOIN PartsT ON SinglePartPaybackSumQ.PartID = PartsT.PartID

Answer 1

[在设计视图中打开“回扣”查询，右键单击“ CustomerT”和“ PaybackT”表之间的联接，然后选择“联接属性”以打开此对话框：

将联接属性更改为“包括来自“ CustomerT”的所有记录，并且仅包括来自“ PaybackT”的那些联接字段相等的记录。”

这应该给您您所需要的。

问候，