I'm using wp_get_attachment_image_src to retrieve image URL.
Codex is simple for this function and starting from an ID on my database I used
wp_get_attachment_image_src in this way:
$image_url = wp_get_attachment_image_src(2447); echo $image_url;
where 2447 is an ID of an attachment in my wp_posts db table (already checked).
Everything seems correct, but trying to execute the code the
wp_get_attachment_image_src returns always