Difference

[Kalpesh K Rawal]

Can any give me the difference between HIbernate and EJB?

[Mark Spritzler]

EJB is a specification for distributed enterprise java objects. You have Stateless and Stateful Session Beans and Entity Beans. Hibernate is on Object Relational Mapping tool to map relational database tables to your object model.

Hibernate is a solution to the problems of using Entity Beans. So it is like a replacement for the Entity Bean part of EJBs. However, JBoss's 4.x implementation of EJB 3.0 Entity Beans is in fact Hibernate 3.x

Mark

[Praful Thakare]

Hi Mark,

I have seen one application where stateless sessionbeans are used with hibernate ,but data is not persisted i.e setCacheable is called on query object with false value.

do you think use of hibernate serves any advantage in this case ?

Cheers
-P

[Paul Sturrock]

I have seen one application where stateless sessionbeans are used with hibernate ,but data is not persisted i.e setCacheable is called on query object with false value.

setCacheable() flags a whether a Query can be cached in the second-level cache. Its got nothing to do with persistence.

[Praful Thakare]

setCacheable() flags a whether a Query can be cached in the second-level cache. Its got nothing to do with persistence

gosh...was under very wrong impression,then how to tell hibernate not to persist data.

also my orignal question,is it good to have hibernate in this framework ?

Thanks a lot Paul

Cheers
-P

[Mark Spritzler]

To tell Hibernate not to persist, you just don't flush the Session or commit.

But why would you use Hibernate if you didn't want to store and update data in a database?

Mark

[Praful Thakare]

Hi Mark,

sorry for the confusion with statemen below.

I have seen one application where stateless sessionbeans are used with hibernate ,but data is not persisted i.e setCacheable is called on query object with false value.

I meant there is no caching of data at hibernate layer.


-Praful

[Paul Sturrock]

There is always caching of data in the Hibernate Session (which is why it is also known as the first level cache). That is implicit and unavoidable, unless you constantly flush the Session (which would be a pointless thing to do).

[Praful Thakare]

intresting...Thanks a bunch Paul

Cheers
-Praful

[uma prasath]

Hi paul,
"There is always caching of data in the Hibernate Session (which is why it is also known as the first level cache). That is implicit and unavoidable, unless you constantly flush the Session (which would be a pointless thing to do). "


As per my understanding, how i can visualize caching is hibernate will fetch data from the table and populate it in a database object and store it in memory. Is it right ??

Thanks

[Paul Sturrock]

Exactly right.