Explode the results to add a nested tree to a database in PHP and order it

I'm using a nestedsortable jQuery plugin that gives me the order/sort of the elements serialized.

And example of this serialitzation (root means parent开发者_C百科_id=0):

id[1]=root&id[5]=1&id[2]=1&id[3]=1&id[4]=3

First thing I'll do is explode by &:

$serialized = "id[1]=root&id[5]=1&id[2]=1&id[3]=1&id[4]=3";

$exploded = explode("&", $serialized);

But I don't know then how to manage a id[1]=root or id[3]=1. How I can do it?

And another question. In this way I don't know which is how to store the order. When I've the exploded with in array like array("id"=>1, "parent"=>"root"); I've to store the order. I will do it with an index, but how I recognise nested levels?

An example:

$i = 0;

foreach($exploded as $explode)
{
    //update every id in MySQL and set parent=$explode["parent"] and order=$i
    $i++;
}

But if I've N levels, how I can have a index $i for every one of them?

Thank you in advance!

Rather than exploding, you could try parse_str()

<?php
parse_str("id[1]=root&id[5]=1&id[2]=1&id[3]=1&id[4]=3",$result);
print_r($result);
?>

From there you can work with the array.