如何从 MySQL 表中检索数据并使用 PHP 将其插入 QR 码？

Question

我有这个 PHP 代码，它用给定的数据创建一个二维码：

<?php

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

   $tempDir = JPATH_SITE . '/images/';   
   $codeContents = 'This Goes From File';
   $fileName     = 'qr_'.md5($codeContents).'.png';

   $pngAbsoluteFilePath = $tempDir.$fileName;
   $urlRelativeFilePath = JUri::root() .'images/' . $fileName;

   if (!file_exists($pngAbsoluteFilePath)) {
      QRcode::png($codeContents, $pngAbsoluteFilePath);
   }
   else {
      echo "Not working!";
   }

   echo '<img src="'.$urlRelativeFilePath.'" />';

?>

我们需要的是连接到一个 MySQL 表 (#__rsforms_submissions)，检索一些字段（例如，姓名和邮件、电话）并将它们插入 QR 码而不是示例提供的数据。为此，我将检索登录用户的用户

$user = JFactory::getUser();
$username = JUserHelper::getUsername($user->id);

然后，MySQL 查询看起来像

SELECT Name,Mail, Phone FROM #__rsforms_submissions WHERE Username = $username

但是，下一步是什么？如何将这些值插入 PHP 代码？ 谢谢！

丹妮

Answer 1

我假设您正在使用 Joomla。我不知道 Joomla，但我可以从 selecting and retrieving SQL data 中弄清楚：

<?php

/* get username */
$user = JFactory::getUser();
$username = JUserHelper::getUsername($user->id);

/* get data from database */
// Get a db connection.
$db = JFactory::getDbo();

// Create a new query object.
$query = $db->getQuery(true);

// Select all records from the user profile table where key begins with "custom.".
// Order it by the ordering field.
$query->select($db->quoteName(array('Name', 'Mail', 'Phone')));
$query->from($db->quoteName('#__rsforms_submissions'));
$query->where($db->quoteName('Username') . ' LIKE '. $db->quote('\'' . $username . '\''));
$query->order('ordering ASC');

// Reset the query using our newly populated query object.
$db->setQuery($query, 0, 1); // 0 = start, 1 = number of records
$row = $db->loadRow();

/* create the qrcode */
include(JPATH_LIBRARIES . '/phpqrcode/qrlib.php');

$tempDir = JPATH_SITE . '/images/';
$codeContents = $row->Name . ', ' . $row->Mail . ', ' . $row->Phone . ', '; // this is what goes into qrcode
$fileName     = 'qr_'.md5($codeContents).'.png';

$pngAbsoluteFilePath = $tempDir.$fileName;

if (!file_exists($pngAbsoluteFilePath)) {
  QRcode::png($codeContents, $pngAbsoluteFilePath);

  $urlRelativeFilePath = JUri::root() .'images/' . $fileName;
  echo '<img src="'.$urlRelativeFilePath.'" />';
}
else {
  echo "Not working!";
}

注意：它未经测试！但是，它应该让您了解如何操作。