Reading pdfs rails

Hi. I am a complete newbie to Ruby - and not even a techie so please be gentle. I have been tasked with writing an internal website that lists the Safe Operating Procedures at our factory. I have knocked out the index, show and edit forms without a problem (by cheating and using RubyMine…no way am I that proficient on my own).
An operator can look up the list of SOPs he needs for his workstation. Ideally he would be able to call up the pdf’s of the actual SOP document by clicking a button in the table adjacent to the ‘show’ and ‘edit’ buttons Rails so magically creates… but nowhere can I find how to do this. Does anybody have a pointer, please? Thanks!
Just to add that the pdf’s already exist. THey have been given the name of the primary key in the SOP table of MySQL. SO pdf 12345.pdf is the SOP 12345 in MySQL