NHibernate includes a number of identity generation strategies and includes an extension mechanism for custom through NHibernate.Id.IIdentifierGenerator.
, insert, . <generator class="trigger-identity" />.
IIdentifierGenerator <generator class="My.Namespace.MyIdentifierGenerator" />.
, :
Id( x => x.Id ).GeneratedBy.Custom<NHibernate.Id.TriggerIdentityGenerator>();
Id( x => x.Id ).GeneratedBy.Custom<My.Namespace.MyIdentifierGenerator>();