wordpress sorting using array merge by price in ascending order but price with 0 must be show last

hope this will usefull to some one.

<?php
/* ADDED by for sorting ASCENDING order but call for price (ie price with 0) last */
function my_sort_custom( $orderby, $query ){
    global $wpdb;
    $orderby =  "   case when CAST(meta_value AS SIGNED) = '0' then 1 else 0 end ,CAST(meta_value AS SIGNED)   ";
    return  $orderby;
}
add_filter('posts_orderby','my_sort_custom',10,2);
global $wp_query;
$args = array_merge( $wp_query->query_vars, array('meta_key' => 'price'));

query_posts( $args );
?>