Pagination pencarian memberi saya Peringatan: Pembagian dengan nol

Saya mendapat peringatan ini > Peringatan: Pembagian dengan nol ‹ jika saya mengetik sesuatu yang tidak ada di database.

Jika saya mengetik sesuatu yang ada semuanya berfungsi dengan baik, saya tidak dapat menemukan atau menyelesaikan masalah.

Di bawah ini adalah skrip yang saya gunakan saat ini, keterampilan php saya tidak sempurna tetapi saya mencobanya.

<?php 


$button = mysql_real_escape_string($_GET ['submit']);
$search = $str = $stt = mysql_real_escape_string(strip_tags($_GET ['search']));
$str = strtoupper($str);
$stt = mb_convert_case($str, MB_CASE_TITLE, "UTF-8");

if(strlen($search)<=2) {

echo 'Nothing found for <b>'.strip_tags($str).'</b>. Please try something else ! ';

}else{

echo 'You searched for <b>'.$stt.'</b> ';


echo "";
include 'extern_/connectsearch.php';

$search_exploded = explode (" ", $search);

foreach($search_exploded as $search_each)
{
$x++;
if($x==1)
$construct .="title LIKE '%$search_each%'";
else
$construct .="AND title LIKE '%$search_each%'";
   }



$constructs ="SELECT * FROM table WHERE $construct";
$run = mysql_query($constructs);

$foundnum = mysql_num_rows($run);

if ($foundnum==0)

echo 'No results for <b>'.$search.'</b> ';

else
{ 


$per_page = 36;  
$id = (int)mysql_real_escape_string($_GET['page']);
$max_pages = ceil($foundnum / $per_page);
if(!$id)
$id=0; 


$p_num = $per_page*$id;  


if($id) 
    $p_num = ($id - 1) * $per_page;             //first item to display on this page
else
    $p_num = 0;

$getquery = mysql_query("SELECT * FROM `table` WHERE $construct ORDER BY date DESC  LIMIT $p_num, $per_page");




$title = $row ['title'];

$url = $row ['url'];


while($row = mysql_fetch_assoc($getquery))
{




echo '<div class="grid">


<a href="/id'. $row['url'] .'"  
id="'. $row['id'] .'" 
alt="'. $row['title'] .'" 
title="'. $row['title'] .'" 
target="_blank">

<h3 class="style">'. substr($row['title'], 0, 34).' ...</h3>

</a>



</div>
</div>
</div>
              ';


 }


 }
echo '<center>';


?>

 <!-- pagination -->

<?php

echo '<center>';


    $page = $id;
    $total_pages = $foundnum;
    $limit = $per_page;
    if ($page == 0) $page = 1;                  
    $prev = $page - 1;                          
    $next = $page + 1;                          
    $lastpage = ceil($total_pages/$limit);      
    $lpm1 = $lastpage - 1;  
    $adjacents = 5;     




    $pagination = "";
    if($lastpage > 1)
    {   
        $pagination .= "<div class=\"paginate\">";

        if ($page > 1) 
            $pagination.= "<a href=\"".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$prev\">Prev</a>";



        if ($lastpage < 7 + ($adjacents * 2))   
        {   
            for ($counter = 1; $counter <= $lastpage; $counter++)
            {
                if ($counter == $page)
                    $pagination.= "<a href='/id".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$counter' class='current'>$counter</a>";
                else
                    $pagination.= "<a href=\"".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$counter\">$counter</a>";                   
            }
        }
        elseif($lastpage > 5 + ($adjacents * 2))    
        {

            if($page < 1 + ($adjacents * 2))        
            {
                for ($counter = 1; $counter < 4 + ($adjacents * 2); $counter++)
                {
                    if ($counter == $page)
                        $pagination.= "<a href='/id".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$counter' class='current'>$counter</a>";
                    else
                        $pagination.= "<a href=\"".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$counter\">$counter</a>";                   
                }

            }
            //in middle; hide some front and some back
            elseif($lastpage - ($adjacents * 2) > $page && $page > ($adjacents * 2))
            {

                for ($counter = $page - $adjacents; $counter <= $page + $adjacents; $counter++)
                {
                    if ($counter == $page)
                        $pagination.= "<a href='/id".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$counter' class='current'>$counter</a>";
                    else
                        $pagination.= "<a href=\"".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$counter\">$counter</a>";                   
                }

            }

            else
            {

                for ($counter = $lastpage - (2 + ($adjacents * 2)); $counter <= $lastpage; $counter++)
                {
                    if ($counter == $page)
                        $pagination.= "<a href='/id".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$counter' class='current'>$counter</a>";
                    else
                        $pagination.= "<a href=\"".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$counter\">$counter</a>";                   
                }
            }
        }


        if ($page < $counter - 1) 
            $pagination.= "<a href=\"".$_SERVER['PHP_SELF']."?search=$search&submit=search&page=$next\">Next</a>";

        $pagination.= "</div>\n";       
    }

    echo $pagination;

echo '</center>';
} 

?>

Peringatan: Pembagian dengan nol di home/search.php online 348

baris 348

$halaman terakhir = ceil($total_pages/$batas);

Dan hal lain yang ingin saya ketahui adalah apakah skrip ini cukup aman?

Bantuan apa pun dihargai. Terima kasih sebelumnya