Can I store an equation and/or random number generator inside of a SQL database? If so, how?

I'm still in college and I'm trying my hand at designing my own applications, for practice and also for funsies, but I'm having some big questions.

Currently, I'm attempting to design an application that uses a relational database backend to store records related to a pen-and-paper RPG that a friend and I have been designing. It will need to store characters, weapons, items, etc. Since it's based off of a sci-fi universe, there are guns, etc.

Now, I'm stuck in the conceptual stages here because I'm not sure how I would store some of the weirder to grasp types of information here. Since it's a tabletop RPG, there are dice involved, typically referred to as D4, D6, D10, D20, etc. and a lot of these weapons, for example, have several kinds of attacks each (they're guns, so it's like firing modes, etc.) and a typical attack would be something like "D20 + 20."

Now, I know that I could just store it as a string variable, but I was hoping to design this in such a way that I could actually add some dice-rolling/etc. functionality to it. Is there a simple or effective way of storing a Math.random variable (not the result, mind you, but the actual range number) in a SQL record so that I could just grab it and use it real quick?

For extra context, I was hoping to have one table of the actual weapon templates & stats and another table of just actual instances of those weapons, so I could keep track of ammo in each gun, who owns it, etc.

I'm using Netbeans and a Derby database. Thanks for any help you guys.