<?php
include 'inc.php';
$timestamp = 10;
$id = 1;
$query1 = $db->query("SELECT distinct(b.from)
FROM msgs b
where b.`to` = 'admin' or b.`from` = 'admin'
GROUP BY b.from
order by b.idz desc");
while($row = $query1->fetch(PDO::FETCH_ASSOC))
{
	$query2 = $db->query("SELECT `idz` from msgs where `from` = '$row[from]' order by `idz` DESC LIMIT 1");
	$row3 = $query2->fetch(PDO::FETCH_ASSOC);
	$array = array(
		
		"$id" => "$row3[idz]"
		
	);
	$id ++;
};
var_dump($array);