如果为null，则显示零

Question

我在一个表单上有一些VBA代码，它可以查找查询中的错误总数。

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null时，我需要向该VBA代码添加什么条件才能自动填充零值？

Answer 1

您可以将DLookup值提供给Nz，并将结果直接分配给文本框，这简化了代码。

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