Is there a way to create an entity that does not map to a table?

What I am trying to do is create a Company domain object. This will contain departments, etc that are mapped to the company entity logically. We do not have a company entity in our database however, the database as a whole is logically within the context of the company.

Does anyone know how I would define the mappings for a Company entity that does not have a corresponding mapping table? I can't figure out how I would load it since there is no table to query against.

you might be able to create a view to mimic the virtual table