<?xml version="1.0" ?>
<hibernate-mapping xlmns="urn::nhibernate-mapping-2.2" namespace="Classes" assembly="Classes" auto-import="true">
<class name="Classes.Artist, MusicStore" table="Artists">
<id name="ArtistID" >
<column name="ArtistID" not-null="true"/>
<generator class="native"/>
</id>
<property name="ArtistName" column="ArtistName"/>
</class>
</hibernate-mapping>

Конфиг
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-configuration>
<session-factory xmlns="urn:nhibernate-configuration-2.2">

<property name="connection.provider"> NHIbernate.Connection.DriverConnectionProvider </property>
<property name="connection.driver_class"> NHibernate.Driver.SqlClientDriver </property>
<property name="dialect">NHibernate.Dialect.MsSql2005Dialect</property>
<property name="connection.connection_string">Server=(local)//SQLEXPRESS;Initial Catalog=MusicStore;Integrated Security=SSPI;</property>
<property name="show_sql">true</property>

<mapping resource="Classes.Artist.hbm.xml" assembly="Classes.Program" />

</session-factory>
</hibernate-configuration>

И далее все классы
using System;
using System.Collections.Generic;
using System.Text;

namespace Classes
{
public class Artist
{
private int artistID;
private string artistName;

public virtual int ArtistID
{
get { return artistID; }
set { artistID = value; }
}

public virtual string ArtistName
{
get { return artistName; }
set { artistName = value; }
}

public Artist()
{
}

public Artist(int idOfArtist, string nameOfArtist)
{
artistID = idOfArtist;
artistName = nameOfArtist;
}
}
}


using System;
using System.Collections.Generic;
using NHibernate;
using NHibernate.Cfg;
using Classes;

namespace Classes
{
class Program
{
static void Main()
{
Configuration config = new Configuration();
config.AddFile("Artist.hbm.xml");

ISessionFactory factory = config.Configure("NHibernate.cfg.xml").BuildSessionFactory();
ISession session = factory.OpenSession();

ITransaction transaction = session.BeginTransaction();

Artist artist = new Artist(1, "Oasis");

session.Save(artist);
transaction.Commit();
int artistID = artist.ArtistID;

session.Flush();

Artist artist1 = session.Get<Artist>(artistID);

if (artist == artist1)
Console.WriteLine("Done!!!");

session.Close();
Console.ReadKey();
}
}
}