how can we search maximum 10 record from mysql database

<?php
include("config.php");

$total = "select Total from student";
$x= mysql_query($total);

while($t = mysql_fetch_array($x))
{
    $numbers[] =$t['Total'];

    function maxN(array $numbers, $n)
    {
        $maxHeap = new SplMaxHeap;
        foreach($numbers as $number)
        {
            $maxHeap->insert($number);
        }
        return iterator_to_array(new LimitIterator($maxHeap, 0, $n));
    }
    print_r( maxN( $numbers, 10 ) );

}


//print_r( maxN( array(7,54,2,4,26,7,82,4,34,99,21,67), 4 ) );

$merit = "select merit from student";
$result = mysql_query($merit);

while($raw = mysql_fetch_array($result))
{

}

?>