public function getOnlineUsers()
{
AppUtils::purgeExpiredSessions();
try {
$pdo = getPDO();
$sql = "SELECT DISTINCT(userId) FROM event_subscriptions";
$stmt = $pdo->query($sql);
$results = (array) $stmt->fetchAll(PDO::FETCH_ASSOC);
return $results;
} catch (PDOException $e) {
throw $e;
}
}
