System.Collections.IDictionary cm = sessionFactory.GetAllClassMetadata();
foreach (Type type in cm.Keys)
{
    NHibernate.Persister.Entity.AbstractEntityPersister persister =
        (NHibernate.Persister.Entity.AbstractEntityPersister)cm[type];

    string[] properties = persister.PropertyNames;
}

SELECT syscolumns.*
FROM sysobjects INNER JOIN syscolumns ON sysobjects.id = syscolumns.id
WHERE sysobjects.name = 'YourTableName'
ORDER BY syscolumns.colid

public void getHeaders(Type type)
{

            NHibernate.Metadata.IClassMetadata cm = SessionProvider.Instance._sessionFac.GetClassMetadata(type);
           
            foreach (string s in cm.PropertyNames)
            {
                    Console.WriteLine(s);
            }
}

public void getHeadersByReflection(Type type)
{

          foreach (PropertyInfo i in type.GetProperties())
         {
              Console.WriteLine(i.Name);
          }

}