fluent nhibernate table column type mapping

hi there, i've been working with fluent nhibernate for a couple of months and i think it's a very flexible tool (even if 'tool' is maybe incorrect term) :)

i've to work on a new project and i'm still considering using fluent nhibernate solution to map my db on a repository layer. The matter is that, for some reason i really don't understand, the db is not 'standard' structured.

I mean that tables are not referenced by foreign key, but i do know that there are cases where :

TABLE X: column A type nvarchar TABLE Y: column A type int

X is the table that contains datas (in the form of codes), while Y is the table that contains X.A description.

As if it's an absurd situation!!! but i can't do anything on the db. So the question is: can i map these tables in fluent nhibernate, referencing them even if columns are of different types?

thx in advance