persisting rich domain models using nhibernate

PERSISTING RICH DOMAIN MODELS USING NHIBERNATE

IStarShip

• Intro• Unit Of Work• Identity Map• Demos• Basics• cascade & inverse• querying

• Many-to-many• Legacy databases• Performance

Agenda

• Origins in Java (Hiberante 2001)• First release 2004• Last release 2.1.2 (Nov 2009)• Upcoming 3.0 release (Summer 2010)

• http://nhforge.org/

NHibernate

Transparent persistance

MAPPing

Mapping

ISession ISessionFactory

IQuery & ICriteriaITransaction

ISession

Identity Map/L1 Cache

Unit of Work

maintains a list of objects affected by a business transaction and coordinates the writing out of changes and the resolution of concurrency problems.

DEMo

idgenerators

increment

identity

sequence

hiloseqhilo

uuid.hexuuid.string

guid

guid.comb

assignednative

foreign

id generator - identity

id generator - hilo

id generator - hilo

PRoxy

PRoxy

PRoxy

Fetch Select / Lazy / N plus 1

Fetch join

inverse false

• none• save-update• delete• delete-orphan• all• all-delete-orphan

Cascade

value objects

Components

Components

Components

• table per class hierarchy• table per subclass• table per concrete class

inheritance

Model

Table PER CLass

concurrency

Concurrency

Concurrency - version

Concurrency - version

Concurrency - timestamp

• Composite primary keys• Relations on non-primary keys• Join• SQL Queries• DB Generated fields

legacy

Property-ref

Sql queries

generated - insert

• Batching• Eager loading (eliminate N+1)• Query Cache• L2 Cache

performance

Batching

Batching

NHibernate = endless number of features

i could go on an on...

• http://nhforge.org/• http://ayende.com/blog• http://www.codinginstinct.com• http://sharparchitecture.net/

resources

Torkel.odegaard@gmail.com

http://tlo.googlecode.com/svn/trunk/presentations/nhibernate_elevate