database - NHibernate on a table with two "primary" keys -

i'm learning nhibernate in order layer on rather peculiar legacy database. other applications use same live database, can't make changes affect them.

i've run problem because 1 table, represents hardware devices, has 2 columns used de facto primary keys. 1 real primary key, auto-generated row id. other unique , non-null hardware serial number.

many other tables in database have foreign-key relationship table. however, of them use real primary key - integer row id - foreign key, , use hardware id of device instead.

note in practice hardware id , row id, once paired, remain paired.

will able create mappings deal in nhibernate, or need create views give me more standardized schema, , use instead of triggers make them updatable?

the db in use mssql 2000, in case makes difference.

in situation following:

public class hardwaredevice{     public virtual int id {get; set;}     public virtual string serialnumber {get; set;}     //other stuff }  public class domainthinga {     public virtual int id {get; set;}     public virtual hardwaredevice device {get; set;}     //other stuff }  public class domainthingb {     public virtual int id {get; set;}     public virtual hardwaredevice device {get; set;}     //other stuff } 

map out hardwaredevice class using autogenerated id primary key. examples use fluentnhibernate class maps.

public class hardwaredevicemap : classmap<hardwaredevice> {     public hardwaredevicemap(){         id(x=>x.id).generatedby.native().column("id"); //uses auto number         map(x=>x.serialnumber).column("serialnumber");         //other mappings     } } 

now mapping out other 2 classes:

public class domainthingamap : classmap<domainthinga> {     public domainthingamap(){         id(x=>x.id).generatedby.native(); //uses auto number         references(x=>x.device)           .column("deviceid"); //joins on id in hardwaredevice table default         //other mappings     } }  public class domainthingbmap : classmap<domainthingb> {     public domainthingbmap(){         id(x=>x.id).generatedby.native(); //uses auto number         references(x=>x.device)            .column("serialnumber") //column in domainthingb table            .propertyref("serialnumber"); //joins using serialnumber column (hardware device table)         //other mappings     } } 

the property-ref feature of class maps allows join on columns not primary key these types of legacy database purposes.