Modifing Pagination-Sorting Method to Change Rows Per Page - php

Question

Hi i have a PHP based Pagination and Sorting Method which works fine.
I am able to sort and paginate according to any categories, but having problems when it comes to rows per page.
i have used GET Method to fetch information for pagination and sorting as
if (isset($_GET['rpp'])&& is_numeric($_GET['rpp'])) {
$rowsperpage = mysql_real_escape_string($_GET['rpp']);
}else{
$rowsperpage='5';
}
if (isset($_GET['page']) && is_numeric($_GET['page'])) {
$currentpage = (int) mysql_real_escape_string($_GET['page']);
} else {
$currentpage = 1;
}
if (isset($_GET['order']) && in_array($_GET['order'], $order)) {
$orderby = mysql_real_escape_string($_GET['order']);
}else{
$orderby='id';
}
$sortby = '';
if (isset($_GET['sort'])) {
$sortby = mysql_real_escape_string($_GET['sort']);
}else{
$sortby='desc';
}
for pagination i have used following type of url string
echo " <li><a href='$pagename?order=$orderby&sort=$sortby&rpp=$rowsperpage&page=$nextpage'>Next»»</a>
and my mysql query is
$sql2 = "SELECT * FROM internet_security ORDER BY $orderby $sortby LIMIT $rowsperpage OFFSET $offset";
and in html i have used links to sort categories like
id-desc:
id-asc:
title-desc:
title-asc:
**limit rows by**
5
10
20
My question is
every thing is working fine except when i limit row per page via limit rows by - rows get limited to whatever limit(5,10,20) is selected but then if i click pagination every thing goes to its default set value i.e by id and in DESC order with LIMIT of 5.
and if i do it like
id-desc:
id-desc:
id-desc:
then it works but then i must have at least 12 links for full functionality.which is not a standard approach.
what i want is once a limit is set either by default or by sorting options, i shall be able to sort by id title etc.. and paginatin should works along with it.
i hope i made it clear.
please see what i am doing wrong and suggest any possible solution to my approach.

Answer 1

(Upgrading to an answer)
Store $rpp in a $_SESSION variable, updating only if it's present in $_GET:
if ( isset($_GET[ 'rpp'])) $_SESSION['rpp'] = intval($_GET['rpp']);
elseif (!isset($_SESSION['rpp'])) $_SESSION['rpp'] = 5;
Then use $_SESSION['rpp'] in your query:
$sql2 = "
SELECT *
FROM internet_security
ORDER BY $orderby $sortby
LIMIT $_SESSION[rpp] OFFSET $offset
";