Using NHibernate with lookup tables

Question

If you have a set of tables in the database that strictly consist of a string description and an ID, what is the best way to load these via NHibernate?

So suppose I have a Sandwich class, and a sandwich has a meat, a cheese, and a vegetable, where those three things are lookup tables in the DB. It seems to be the most conformant to NHibernate philosophy to have

public class Meat { string name; int id; }
public class Cheese { string name; int id; }
public class Vegetable { string name; int id; }
public class Sandwich { Meat meat; Cheese cheese; Vegetable vegetable; }

But with a few dozen tables like this in the database, classes seem to proliferate quickly. Suppose I set it up like this:

public class NameAndID { string name; int id; }
public class Sandwich { NameAndID meat; NameAndID cheese; NameAndID vegetable; }

Is this feasible? How would it be implemented in Fluent NHibernate?

Answer 1

You'd need another column to determine the type. You could use an enum for that. Then all your lookups need to include that restriction....

CreateCriteria<NameAndID>.Add(Restrictions.Eq("ntype", E.Meat)

However, I'd prefer separate tables so you can have better foreign keys. Otherwise there is nothing in database constraints to stop you from making a sandwich that is simply 3 pieces of cheese.