سلام این کد رو ببنید لطفا 

function show_task_sort (){
    global $pdo;
    $current_user_id = get_current_user_id();
    $sql = "SELECT * FROM `tasks` WHERE `user_id` = $current_user_id ORDER by `created_at` DESC";
    $stmt = $pdo -> prepare($sql);
    $stmt -> execute();
    $records = $stmt -> fetchAll(PDO::FETCH_OBJ);
    return $records;
}

 :   ':userID' => $current_user_id  وقتی میخوام از روش زیر استفاده کنم برنامه خطا میده

function show_task_sort (){
    global $pdo;
    $current_user_id = get_current_user_id();
    $sql = "SELECT * FROM `tasks` WHERE `user_id` = :userID ORDER by `created_at` DESC";
    $stmt = $pdo -> prepare($sql);
    $stmt -> execute(
    ':userID' => $current_user_id
    );
    $records = $stmt -> fetchAll(PDO::FETCH_OBJ);
    return $records;
}