主题：生产数量大于订单数量输入不进去

生产表datacolchanging事件

If e.DataCol.Name.StartsWith("累计产量") Then
    Dim sum1 As Double = DataTables("订单表").compute("sum(" & e.DataCol.name & ")", "款号='" & e.DataRow("款号") & "'")
    Dim sum2 As Double = DataTables("生产表").compute("sum(" & e.DataCol.name & ")", "款号='" & e.DataRow("款号") & "'")
    If sum2-e.OldValue+e.NewValue > sum1 Then
        msgbox("超出订单数")
        e.cancel = True
    End If
End If