DataGridView обновление данных в базе.

        OleDbDataAdapter myOleDbDataAdapter;
        DataTable Dt1;

            GR_BT1_3_Grid1 = new System.Windows.Forms.DataGridView();
            GR_BT1_3_Grid1.Location = new System.Drawing.Point(20, 47);
            GR_BT1_3_Grid1.Size = new System.Drawing.Size(451, 346);
            GR_BT1_3_Grid1.Name = "GR_BT1_3_Grid1";
            GR_BT1_3_Grid1.Text = "";
            GR_BT1_3_Grid1.RowHeadersVisible = false;
            GR_BT1_3_Grid1.DefaultCellStyle.Font = new Font("Microsoft Sans Serif", 8);
            GR_BT1_3_Grid1.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
            GR_BT1_3_Grid1.CellContentClick += new    DataGridViewCellEventHandler(GR_BT1_3_Grid1_CellContentClick);
            GR_BT1_3_Grid1.CellValueChanged += new DataGridViewCellEventHandler(GR_BT1_3_Grid1_CellValueChanged);
            GR_BT1_3_Grid1.AutoResizeColumns();
            GR_BT1_3_Grid1.TabIndex = 0;
            GR_BT1_3.Controls.Add(GR_BT1_3_Grid1);
 
            string connectionString =
                "provider=Microsoft.Jet.OLEDB.4.0;" +
                "data source=" + MAIN_DB;
            OleDbConnection myOleDbConnection = new OleDbConnection(connectionString);
            OleDbCommand myOleDbCommand = myOleDbConnection.CreateCommand();
            myOleDbCommand.CommandText =
                "SELECT TARIF_NAME, TARIF_PAY, TARIF_CITY, TARIF_VHSPEED, TARIF_ISHSPEED, TARIF_PAYFORGB, TARIF_COSTOUT, TARIF_LOCAL " +
                "FROM TARIF " +
                "WHERE TARIF_INUSE = 'Действующие'";
 
            myOleDbDataAdapter = new OleDbDataAdapter(myOleDbCommand);
            OleDbCommandBuilder myOleDbCommandBuilder = new OleDbCommandBuilder(myOleDbDataAdapter);
            Dt1 = new DataTable();
            myOleDbDataAdapter.Fill(Dt1);
            GR_BT1_3_Grid1.DataSource = Dt1;
            myOleDbConnection.Close();

        private void GR_BT1_3_Grid1_CellValueChanged(object sendder, DataGridViewCellEventArgs e)
        {
            myOleDbDataAdapter.Update((DataTable)GR_BT1_3_Grid1.DataSource);
        }