SQLopen()
        Dim cmd As String = "SELECT * FROM buecher"
        Dim com As New MySqlCommand(cmd, myconn)
        Dim dr As MySqlDataReader = com.ExecuteReader
        While (dr.Read)
            'verfuegbarkeit prüfen!
            'Dim s As String = dr.Item(0).ToString()
            'MsgBox(s)
        End While
            SQLclose()