gymrooster_php/php/auth.php

<?php

session_start();

function isAuthorized() {
  
  require __DIR__ . '/conn.php';

  $result = $conn->query("SELECT * FROM docenten WHERE username = '" . $_SESSION["username"] . "' AND password = '" . $_SESSION["password"] . "'");

  if ($result->num_rows === 1) {
    return true;
  } else {
    return false;
  }
}