How to use the Entity Manager correctly?

Hello

I would like to ask a EntityManager related question. From the tutorials I have read I came across two different categories of examples in which EntityManager is used. In the first type it is like:

EntityManager em;

publicvoid addMethod(Object o)

{

em.persist(o);

}

whereas in the second type of examples, it is like:

EntityManager em;

publicvoid addMethod(Object o)

{

em.getTransaction().begin();

em.persist(o);

em.commit();

}

My question is, what is the difference between the two different approaches?

Thanks

[858 byte] By [rabbiaa] at [2007-11-26 16:52:24]