I have a Cold Fusion web site working with MySQL database that has only around 100 records. Each record has project information and customer info.

Now the customer wants me to link one of my fields which is an id number and is not a primary or foreign key to another application which uses an Oracle database all of which was developed by someone else. Basically tie the two applications together linking this id number. Is this something that is normal and what info do I need to get from the the other application to make this work? I assume he has to allow me to login to his database and allow me to view his tables etc... Please advise.