I will agree that the problem that class hierarchies attempt to solve is a problem one usually does not really have, but in your example you have not solved it at all.
It matches a relational database well, but once you have a just a user reference, you can not narrow it down to an employee without out of band information. If a user should be just one type that can be multiple things at once, you can give them a set of roles.
It matches a relational database well, but once you have a just a user reference, you can not narrow it down to an employee without out of band information. If a user should be just one type that can be multiple things at once, you can give them a set of roles.