object_relational_mapping.md

Object Relational Mapping (ORM)

An ORM tool simplifies the data creation, data manipulation and data access. It is a programming technique that maps the object to the data stored in the database.

• Products:
  1. Hibernate
  2. Java Persistence API (JPA)
  3. EJB, EntityBean
  4. iBats
  5. TopLink

Hibernate Session vs JPA EntityManager

SQL	HS	EM
insert	save(obj)	persist(obj)
load an obj	load/get(, id)	find(, id)
update	load/get + setter	find + setter
delete	delete(obj)	remove(obj)
select	createQuery(hql)	createQuery(JPAquery)
get a result	query.list()	query.getResultList()