create dowload link while retrieving data from mysql

[Helder_1]

I'm coding a simple portal do maintain work history and I'm facing a problem. While php retrieve data from mysql I would like that he create a btn or a link to download a file in a directory (path on mysql).

1- script: http://pastebin.com/mBHCdChK

2- script to retrieve path and print link (get_ra() func): http://pastebin.com/7QEsNywm

3- error on execute: "Notice: Undefined index: in C:\wamp\www\netflow\gestao_trabalhos\scripts\listar_tudo.php on line 46" on every entry on db

Dont worry about security, its a private portal and it will be allocated on a private network.