How to get the filename from file system and create a download link?

as per chat discussion, once you get the attachment ID you can get the url using

 wp_get_attachment_url($attachment_resume_id) 

so in your case you have to

 wp_get_attachment_url($record_s->attachment_resume_id) 

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)