Question

我对Access DB和VB6有问题。

我有一个制作发票的程序，发票编号是唯一的密钥。问题是两个人同时在介绍发票的网络中工作。我需要检查每个人输入的发票编号是否不存在，以免重复。

Private Sub GuardarFactura()

If InvoiceNumberExist Then
    MessageBox UserControl.hWnd, "Invoice number duplicate", "Control de errores", vbExclamation
    Exit Sub
End If

On Error GoTo ErrorGuardar

Dim HayTrans As Boolean

AreaDeTrabajo.BeginTrans
HayTrans = True

Screen.MousePointer = vbHourglass

With recFrasEmi
    .AddNew
    !Numero = teInvoiceNumber
    !Fecha = CDate(teFecha)
    !TotalEuros = Format(CDbl(teTotal), FormatoImporte)
    .Update
    .Move 0, .LastModified
End With

AreaDeTrabajo.CommitTrans
HayTrans = False

DoEvents

Screen.MousePointer = vbDefault

Exit Sub

ErrorGuardar:

    If HayTrans Then AreaDeTrabajo.Rollback
    Screen.MousePointer = vbDefault

    MessageBox UserControl.hWnd, Err.Number & ": " & Err.Description, "Control de errores", vbExclamation

End Sub

function InvoiceNumberExist

    dim RS as recordset

    Sql "Select * From Facturas Where Numero='" & teInvoiceNumber & "'"

    Set RS = BD.OpenRecordset(Sql)
    If Not (RS.EOF And RS.BOF) Then
        InvoiceNumberExist=true
    else
        InvoiceNumberExist=false
    End If

end function

如果用户同时工作，InvoiceNumberExist并不总是工作，我知道我可以使用“ if Err = 3022 then ....”，但是有可能在错误之前找到重复的数字吗？

谢谢

Answer 1

谢谢，然后我认为唯一的解决方案是对错误goto使用：

Private Sub GuardarFactura()

On Error GoTo ErrorGuardar

Dim HayTrans As Boolean

AreaDeTrabajo.BeginTrans
HayTrans = True

Screen.MousePointer = vbHourglass

With recFrasEmi
.AddNew
!Numero = teInvoiceNumber
!Fecha = CDate(teFecha)
!TotalEuros = Format(CDbl(teTotal), FormatoImporte)
.Update
.Move 0, .LastModified
End With

AreaDeTrabajo.CommitTrans
HayTrans = False

DoEvents

Screen.MousePointer = vbDefault

Exit Sub

ErrorGuardar:

If HayTrans Then AreaDeTrabajo.Rollback
Screen.MousePointer = vbDefault

If Err=3022 Then
   MessageBox UserControl.hWnd, "Invoice number duplicate", "Control de errores", vbExclamation
Else
   MessageBox UserControl.hWnd, Err.Number & ": " & Err.Description, "Control de errores", vbExclamation
End If

End Sub

在Access数据库中控制重复密钥

1 个答案: