To create User objects:
--for each type, I have two constructors, one with only the basics and one with all info.  Feel free to just choose for now i guess :)

STUDENT:
	public Student(String userName, String password, String email) {
		super(userName, password, email);
		super.setRole("S");
	}

	public Student(String userName, String firstName, String lastName, String email, String password) {
		super(userName, firstName, lastName, email, password);
		super.setRole("S");
	}

TEACHER: 
	public Teacher(String userName, String firstName, String lastName, String email, String password) {
		super(userName, firstName, lastName, email, password);
		super.setRole("T");
	}

	public Teacher(String userName, String password, String email) {
		super(userName, password, email);
		super.setRole("T");
	}

ADMIN:
	public Admin(String userName, String firstName, String lastName, String email, String password) {
		super(userName, firstName, lastName, email, password);
		super.setRole("A");
	}

	public Admin(String userName, String password, String email) {
		super(userName, password, email);
		super.setRole("A");
	}

ADDING TO DB:
		//create AppDAO object
		AppDAO appDAO = new AppDAO();
		
		//pass in User object (any of the three subclasses will work)
		appDAO.insertNewUser(user);

		//profit!!?