kk Star Ratings Snippet

global $wpdb;
$Posts = $wpdb->get_results("SELECT ID FROM " . $wpdb->posts);
foreach ($Posts as $post)
{
    if(!get_post_meta($post->ID, _kksr_avg, true))
    {
        update_post_meta($post->ID, '_kksr_avg', 0);
    }
}