<?php
$c = mysqli_connect('localhost', 'mzyrek', 'kasztelan', 'mzyrek_baza') or die('Blad polaczenia z baza');

$q = mysqli_query($c, 'SELECT * FROM Komputery') or die(mysqli_error($c));

while($r = mysqli_fetch_assoc($q) ) {
    echo '<p>' . $r['id_komp'] . ' | ' . $r['nazwa'] . ' | ' . $r['id_sali'] . '</p>';
}