<?php


echo "<table><tr><th><a href='index.php?order=name'>Студент</a></th><th><a href='index.php?order=groupindex'>Номер группы</a></th><th><a href='index.php?order=points'>Баллы</a></th></tr>";

$sort = 'points';
if (isset($_GET['order'])) {
    $sort = $_GET['order'];
}

$STH = $DBH->query("SELECT name, sname, groupindex, points FROM students ORDER BY $sort");
