What is Best way to enforce Primary Keys

I am developing my first Oracle application and it seems like everyday a new issue comes up. There are many things which I am certain that others have already figured out the best approach to.

For example, I am currently trying to figure out the best way to enforce primary keys...particularly when the primary key spans more than one field.

We are also using a numeric backbone for the actual key being used to link tables.

So...The real primary key is this numeric field with a generated number.

But....The next 3 fields contain char,number,date values, the combination of which define a unique record. I need to make sure that the user does not enter duplicates of THAT unique entity.

QUESTION: What is the best way to enforce this multi-field primary key?

Thanks in advance

-- 


------------------------------------------------------------------

Steve Schow    | But you don't have to use the claw, if you
sjs_at_netcom.com | pick the pear with the big paw paw......
               | Have I given you a clue......?
               |                       - Baloo the Bear


------------------------------------------------------------------