How can I retrieve data from MySQL table and insert it into QR code using PHP?

Question

I have this PHP code that should retrieve data from a MySQL database and embed it into a a QR code:

 <?php
    include(JPATH_LIBRARIES . '/phpqrcode/qrlib.php');

$db     = JFactory::getDbo(); 
$user   = JFactory::getUser();

$query = $db->getQuery(true);    
$query->select($db->quoteName(array('Nom', 'Cognoms', 'eCorreu')))
      ->from($db->quoteName('#__rsform_socis'))
      ->where($db->quoteName('Username') . ' = '. $db->quote($user->Username));     
$db->setQuery($query);
$codeContents = $db->loadObjectList();

$data  = $codeContents[0]->Nom;
$data .= $codeContents[0]->Cognoms;
$data .= $codeContents[0]->eCorreu;

$tempDir  = JPATH_SITE . '/images/';   
$fileName = 'qr_'.md5($data).'.png';   
$pngAbsoluteFilePath = $tempDir.$fileName;
$urlRelativeFilePath = JUri::root() .'images/' . $fileName;

if (!file_exists($pngAbsoluteFilePath)) {
    QRcode::png($data, $pngAbsoluteFilePath);
}       
echo '<img src="'.$urlRelativeFilePath.'" />';
    ?>

However, I just get an image icon. Can anyone help? Thanks!

Dani

Answer 1

Update:

Ok I've done a test. I connected to the #__users table and pulled the name and username of the ID of the current logged in user like so:

include(JPATH_LIBRARIES . '/phpqrcode/qrlib.php');

$db     = JFactory::getDbo(); 
$user   = JFactory::getUser();

$query = $db->getQuery(true);    
$query->select($db->quoteName(array('name', 'username')))
      ->from($db->quoteName('#__users'))
      ->where($db->quoteName('id') . ' = '. $db->quote($user->id));     
$db->setQuery($query);
$codeContents = $db->loadObjectList();

$data  = $codeContents[0]->name;
$data .= $codeContents[0]->username;
  
$tempDir  = JPATH_SITE . '/images/';   
$fileName = 'qr_'.md5($data).'.png';   
$pngAbsoluteFilePath = $tempDir.$fileName;
$urlRelativeFilePath = JUri::root() .'images/' . $fileName;

if (!file_exists($pngAbsoluteFilePath)) {
    QRcode::png($data, $pngAbsoluteFilePath);
}       
echo '<img src="'.$urlRelativeFilePath.'" />';

This created the QRCode. I then scanned it on my phone and it displayed the correct data. So in your case, change the dtabase table name to whatever you wish and type in the fields you want to get from that table.

array('name', 'username') // Add what you want here

Then you need to define them like so:

$data .= $codeContents[0]->NAME_OF_FIELD;

You will see a . (dot) before the =(equals) symbol. This needs to be done for all of them apart from the first one as shown on my code.

Hope this helps