Custom redirects with using SQL

I wrote function for short url. Maybe it will be helpful for someone:

function short_url(){
    global $post;
    if (preg_match('/^http:\/\/example.com\/page\/[0-9]{1,4}$/', "http://".$_SERVER["HTTP_HOST"] . $_SERVER["REQUEST_URI"]))
    { 
        $my_id = intval(preg_replace('/[^0-9]+/', '', $_SERVER["REQUEST_URI"]), 10);
        global $wpdb;
        $myquery = $wpdb->get_row($wpdb->prepare("SELECT * FROM wp_mytable WHERE ID=%d", $my_id));
        $short_url="http://example.com/?page_id=".$myquery->page_id."&user_id=".$myqery->user_id;

        wp_redirect($short_url);
        exit();
    }
}
add_action( 'template_redirect', 'short_url' );