Vb.net 如何管理正确的代码

我有可以绑定到控件和datagridview的数据源和表。我可以向数据表添加记录，也可以在datagridview上查看，但不能使用datagrid更新和删除记录。我有以下代码。如果有人能帮助我，我将不胜感激

Private Sub add_and_update()
        Dim con As VistaDBConnection
        Dim Cmd As New VistaDBCommand
        Dim constring As String
        constring = String.Format("Data Source =v_slot_database.vdb3", (System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase)))
        con = New VistaDBConnection(constring)
        con.Open()
        Dim metertable As DataTable = Me.DataSet1.Tables.Item("tbl_meter")
        Dim row As DataRow = metertable.NewRow()
        row.Item("CDate") = txtdate.Text
        row.Item("Machine_No") = txtno.Text
        row.Item("Turnover") = txtturnover.Text
        row.Item("Total Win") = txttotalwin.Text
        row.Item("Games Played") = txtgamesplayed.Text
        row.Item("Credit In") = txtcreditin.Text
        row.Item("Bill In") = txtbillin.Text
        row.Item("Cancel Credit") = txthandpay.Text
        metertable.Rows.Add(row)
        Me.DataSet1.tbl_meter.AcceptChanges()
        Me.Tbl_meterTableAdapter.Update(Me.DataSet1.tbl_meter)
        clear_fields()
        con.Close()
        con = Nothing
    End Sub

 Private Sub clear_fields()
        Me.txtno.Text = "0"
        Me.txtturnover.Text = "0"
        Me.txttotalwin.Text = "0"
        Me.txtgamesplayed.Text = "0"
        Me.txtcreditin.Text = "0"
        Me.txtbillin.Text = "0"
        Me.txthandpay.Text = "0"
        Me.txtno.Focus()
    End Sub

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我开始给自己答案。：）我找到了理由。我的表上没有主键。我补充道，问题就解决了

尝试更新或删除时是否出现错误？你得到任何回应了吗？没有，实际上它是从gridview中删除的，但没有更新。