$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';
mysql_connect($dbhost, $dbuser, $dbpass);
mysql_select_db( 'db1' );
$query = mysql_query("SELECT * FROM users");
$array = array();
while($row = mysql_fetch_array($query)) {
    $array[] = $row;
}

$result = array_diff($array,$array);
echo $result;