vba - 如果为 null，则显示零

Question

我在一个表单上有一些 VBA 代码，它执行查询中的错误总数的查找。

Private Sub cboProjectID_Change() 
   Dim VarTotalErrors As Variant 
   VarTotalErrors = DLookup("[total errors]", "[Project_Total_Errors_Query]", "[Project_ID] = " & VarComboKey) 
   Me.txttotalerrors = VarTotalErrors 
End Sub

当 total_errors 为空时，我需要向此 VBA 代码添加什么条件以自动填充零值？

Answer 1

您可以将DLookup值Nz直接提供给文本框并将其分配给文本框，从而简化代码。

Private Sub cboProjectID_Change()
    Me.txttotalerrors = Nz(DLookup("[total errors]", _
        "[Project_Total_Errors_Query]", _
        "[Project_ID] = " & VarComboKey), 0)
End Sub

Answer 2

Private Sub cboProjectID_Change() 
   Dim VarTotalErrors As Variant 
   VarTotalErrors = DLookup("[total errors]", "[Project_Total_Errors_Query]", "[Project_ID] = " & VarComboKey) 
   If Nz(VarTotalErrors) = 0 Then
       Me.txttotalerrors = "0" 
   else
       Me.txttotalerrors = VarTotalErrors 
   end if
End Sub