MySQL calls with MODx Revolution

<?php
$haku = mysql_query( "SELECT id, pagetitle, parent, description, content FROM `revo_site_content` WHERE `parent`=3 ORDER BY `id` DESC  LIMIT 2");

while ( $tiedot = mysql_fetch_array ( $haku ) )
{

}
?>

<?php
$c = $modx->newQuery('modResource');
$c->select(array('id', 'pagetitle', 'parent', 'description', 'content'));

$c->where(array(
   'published'=>'1',
   'deleted'=>'0',
   'parent'=>'3',
));

$c->sortby('id', 'DESC');

$docs = $modx->getCollection('modResource', $c);

foreach ($docs as $doc) {
    $output .= '<br />Title:' . $doc->get('pagetitle') . ' ID:' . $doc->get('id') .'<br />';
}
return $output;

$c->limit(2);

$c->limit(10,2);