How to generate barcode in php

Question

I got this example code from my lecturer. I would like to modify the code so that it can fetch my data from database to generate barcode. I have read a few article but I still have any idea about generating barcode. So what should I do right now? Your help is really appreciated.

<?php
    // Including all required classes
    require_once('class/BCGFontFile.php');
    require_once('class/BCGColor.php');
    require_once('class/BCGDrawing.php');

    // Including the barcode technology
    require_once('class/BCGcode39.barcode.php');

    // Loading Font
    $font = new BCGFontFile('./font/Arial.ttf', 18);

    // Don't forget to sanitize user inputs
    $text = isset($_GET['text']) ? $_GET['text'] : '7895565';

    // The arguments are R, G, B for color.
    $color_black = new BCGColor(0, 0, 0);
    $color_white = new BCGColor(255, 255, 255);

    $drawException = null;
    try {
        $code = new BCGcode39();
        $code->setScale(2); // Resolution
        $code->setThickness(30); // Thickness
        $code->setForegroundColor($color_black); // Color of bars
        $code->setBackgroundColor($color_white); // Color of spaces
        $code->setFont($font); // Font (or 0)
        $code->parse($text); // Text
    } catch(Exception $exception) {
        $drawException = $exception;
    }

    /* Here is the list of the arguments
    1 - Filename (empty : display on screen)
    2 - Background color */
    $drawing = new BCGDrawing('', $color_white);
    if($drawException) {
        $drawing->drawException($drawException);
    } else {
        $drawing->setBarcode($code);
        $drawing->draw();
    }

    // Header that says it is an image (remove it if you save the barcode to a file)
    header('Content-Type: image/png');
    header('Content-Disposition: inline; filename="barcode.png"');

    // Draw (or save) the image into PNG format.
    $drawing->finish(BCGDrawing::IMG_FORMAT_PNG);
?>

Answer 1

Your barcode is generated from this code: $code->parse($text); // Text

Where $text is $text = isset($_GET['text']) ? $_GET['text'] : '7895565';

So all you need to do $text = $db->fetch();