courses.php

<!DOCTYPE html>
<html>
 <head>
  <meta charset="UTF-8"/>
  <title>Harvard Extension Courses</title>
  <link rel="stylesheet" href="styles/site.css" type="text/css"/>
 </head>
 <body>
<h1>Harvard Extension Courses</h1>
<p><a href="departments.php">Return to Department List</a></p>
<?php

// use Dotenv to load database info from .env file
// DB_HOST, DB_USER, DB_PW,     DB_NAME
// host,    user,    password,  database name
require_once('vendor/autoload.php');
$dotenv = Dotenv\Dotenv::createImmutable(__DIR__);
$dotenv->safeLoad();

// Connecting, selecting database
$mysqli = new mysqli($_ENV['DB_HOST'],$_ENV['DB_USER'],$_ENV['DB_PW'],$_ENV['DB_NAME']);
if ($mysqli->connect_errno) {
    echo "Failed to connect to mysql: ".$mysqli->connect_errno." ".$mysqli->connect_error;
}

$dept_code = $_GET['department_code'];
$sqlescaped_dept_code = $mysqli->real_escape_string($dept_code);
$dept_code_html = htmlentities($dept_code);
?>
<h2>Department - <?php echo $dept_code_html ?></h2>
<?php
// Performing SQL query
$query = <<<ENDQUERY
SELECT
  department,
  department_code,
  course_number,
  term,
  academic_year,
  short_title,
  title,
  description,
  faculty_description
FROM
  ext_courses
WHERE
  department_code = '$sqlescaped_dept_code'
ORDER BY
  department,
  course_number,
  title
ENDQUERY;

$result = $mysqli->query($query);

// Printing results in HTML

$i = 0;
while ($row = $result->fetch_assoc()) {
  // calculate year
  $academic_year_display = $row['academic_year'];
  if ($row['term'] == 'Spring' or $row['term'] == 'January') {
    $academic_year_display += 1 ;
  }

  $course_content = <<<ENDCONTENT
  <section class="course">
  <h2 class="abbrev"> $row[short_title] </h2>
  <div>
    <p class="term">$row[term] $academic_year_display</p>
    <p class="title"><strong>$row[title]</strong></p>
    <p class="faculty">$row[faculty_description]</p>
    <p class="description">$row[description]</p>
  </div>
  </section>
ENDCONTENT;
  echo($course_content);
}


// cleanup query result and close connection
$query_result->free();
$mysqli->close();
?>
<footer>
<p><a href="./">PHP/mysql example list</a></p>
    <p>This is a learning example to demonstrate PHP and mysql for the courses CSCI E-12 and CSCI S-12 taught by David Heitmeyer.  <br/>
  The real <a href="https://courses.dce.harvard.edu/">Harvard Extension School course search</a> is at: <a href="https://courses.dce.harvard.edu/">courses.dce.harvard.edu</a>
    </p>
</footer>
</body>
</html>