I'm making a database program. I want the user to be able to define their own columns, as many as they want. How would I then define each record in its class file?(Since the properties would be different user to user)

EDIT:

It's part of a school assignment-it's going to hold different scores and the likes for the teacher for different students they can add, but they will also be able to add a new assignment, test(a column) .