PHP: A clean way of converting an array

What is a clean way to convert an array that looks like this:

[584] => Array ( [link_id] => 1   [site_id] => 5     [COUNT(*)] => 2 )
[585] => Array ( [link_id] => 243 [site_id] => 5     [COUNT(*)] => 2 ) 
[586] => Array ( [link_id] => 522 [site_id] => 89223 [COUNT(*)] => 3 )

To an array where the key is the site_id from above, so for the above example the resulting array would be:

[5] => Array( 1, 2, 243, 2) //Even ones and 0 are link_id, odd ones are count(*)  
[89223] => Array(522, 3)

So, basically, group them by site_id. I still need to keep the relationship between link_id and count(*), in the case above I a开发者_如何学Pythonm doing it by the positions (so 0 and 1 are together, 2 and 3, etc) but I am open to a new structure as well.

Thanks!

---

You mean something like this? (Demo):

$out = array();
foreach($input as $v)
{
    $site_id = $v['site_id'];
    unset($v['site_id']);
    $out[$site_id][] = $v;
}

Or in case you prefer value pairs after each other (Demo):

    ...
    unset($v['site_id']);
    $out[$site_id][] = array_shift($v);
    $out[$site_id][] = array_shift($v);
} ...