Wordpress Update Post Function

function update_parent($parent_id, $post_id){
    global $wpdb;

    $parent_id = (string)$parent_id;
    $post_id = (string)$post_id;

    $result = $wpdb->update( $wpdb->posts, array( 'post_parent' => $parent_id ),array( 'ID' => $post_id ));

    if($result === FALSE){
        return false;
    }else{
        return true;
    }
}