open a file in a folder without knowing the filename

Hi, I'm probably missing something really obvious here but how would I go about opening a file or multiple files in a folder without knowing the filename ahead of time? Loading a file in and sending the contents to a databse I can do but everywhere i've looked all require the filename to be known ahead of time or entered via a form, I'd like to be able to grab a file/all files in a folder and strip them into usable form to insert into a database. Each filename is generated randomly so I need to be able to do it without knowing the filename in advance. Could anybody point me in the right direction? Thanks, Graham