Skip to main content



      Home
Home » Eclipse Projects » EclipseLink » Difference between EntityManager and SessionFactory
Difference between EntityManager and SessionFactory [message #726948] Mon, 19 September 2011 21:54 Go to next message
Eclipse UserFriend
Hello All:

I am new to JPA and often while reading documentation, I see different mechanisms to create queries. One with EntityManager and the other mechanism deals with Sessions. Which is the preferred mechanism?


Session example:
---------------
ReadAllQuery query = new ReadAllQuery(Employee.class);
query.setJPQLString("SELECT OBJECT(emp) FROM Employee emp");
...
List employees = (List)session.executeQuery(query);

Entity Manager example:
----------------------
factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
EntityManager em = factory.createEntityManager();
// Read the existing entries and write to console
Query q = em.createQuery("select t from Todo t");
List<Todo> todoList = q.getResultList();
for (Todo todo : todoList) {
System.out.println(todo);
}

What is the preferred mechanism? Can someone throw somelight?

Thanks
Sridhar
Re: Difference between EntityManager and SessionFactory [message #728099 is a reply to message #726948] Thu, 22 September 2011 10:06 Go to previous message
Eclipse UserFriend
JPA defines the EntityManager interface and it should be used with JPA whenever possible.

The Session API is EclipseLink's native API that existed pre-JPA.

Using JPA is recommend, as it is the standard. If required, you can still access the EclipseLink Session from the JPA EntityManager to access advanced functionality.


--
James : http://wiki.eclipse.org/EclipseLink : http://en.wikibooks.org/wiki/Java_Persistence : http://java-persistence-performance.blogspot.com/
Previous Topic:Re: desktop Swing application with EclipseLink
Next Topic:GeneratedValue on SecondaryTable
Goto Forum:
  


Current Time: Thu Jul 24 14:18:46 EDT 2025

Powered by FUDForum. Page generated in 0.03691 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 3.0.2.
Copyright ©2001-2010 FUDforum Bulletin Board Software

Back to the top