vb.net 2010 ทำยังไงให้อัพเดทแค่เรคคอร์ดเดียว แก้ไม่ได้สักที

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

            Dim myConnection As MySqlConnection
            myConnection = New MySqlConnection("Server=161.246.195.45; User Id = nantawat;Password = 123456; Database = kmitl_database;")
            myConnection.Open()

        Dim intNumRows As Integer
        Dim myCommand As MySqlCommand = myConnection.CreateCommand()
        myCommand.CommandText = "SELECT COUNT(*) FROM dt_in_out WHERE card_id = '" & Me.TextBox1.Text & "' "
        intNumRows = myCommand.ExecuteScalar()

        If intNumRows > 0 Then
            myCommand.CommandText = "UPDATE dt_in_out SET dt_out = '" & Me.Label1.Text & "' WHERE card_id = '" & Me.TextBox1.Text & "'"
            myCommand.CommandType = CommandType.Text
            myCommand.ExecuteNonQuery()
            myConnection.Close()

        Else
            myCommand.CommandText = "INSERT INTO dt_in_out(card_id, dt_in, dt_out)" & _
                    " VALUES('" & TextBox1.Text & "','" & Label1.Text & "','In building')"
            myCommand.CommandType = CommandType.Text
            myCommand.ExecuteNonQuery()
            myConnection.Close()

        End If