Como editar meu código para salvar no mySQL desde o início do XML?

<?php

$xml = simplexml_load_file('test.xml');

foreach($xml->products->product as $product)
{
    $columns = array();
    $data = array();
    foreach($product->children() as $child)
    {
        echo $child->getName() . ": " . $child . "<br />";
        $columns[] = $child->getName();
        $data[] = mysql_real_escape_string((string)$child);
    }
    $col = '`'. implode('`,`',$columns) .'`';
    $val = "'". implode("','",$data)."'";
    $query = "INSERT INTO XML_FEED ($col) VALUES ($val)";
    echo $query;

    mysql_query($query);
}
?>