Hi! My first contact with an ORM was EOF... an ever since I have felt that nothing compares to it ;-).
The thing is, I have had to work with JPA/Hibernate for a few years now... and I feel it has some weaknesses I really do not like, I am thinking about "switching to cayenne" but first i would like to be sure that Cayenne does not have this weaknesses too. List of weaknesses in JPA/Hibernate: -No way to manage an object that "will be persisted", in JPA/Hibernate if you call entityManager.persist(object) and the database does not support sequences (like MS-Sql) an insert will be triggered, and if any of the non nullable fields of the objects is null, it will crash. If your object has a compound primery key, things get worse, because the entityManager can not deal with it until the compound primary key is set, and if you compound primary key is formed by foreign keys pointing to objects that are new too, that means you will not be able to save stuff with with a simple single call to entityManager.persist to one of the objects, cascading will not help you (I really miss something "magic" like ObjectContext.commitChanges() ) -No easy way to know if "an object is dirty" (if it has changed/deleted since it was read from the database, there is just no API for that), and since you can not know what objects will be persisted, and what object have changed, and what objects will be deleted from database, that means you can not easily create an unified API for centralized polymorphic validation (that is no easy way to create validateForSave, or validateForDelete) -No real equivalent for validateForXXX, JPA lifecycle callbacks are not match for validateForXXX because you can not query the database during the lifecycle callbacks, and if you throw an exception inside a lifecycle callback, the JPA/Hibernate entityManager enters an invalid state, and after that you can not continue to use your POJOs, you have to start over with a fresh entityManager... and without you modifications to the POJOs. Note that Hibernate new validation framework does not offer a real solution for this problem... and AFAIK JSR-000303 will not help with this either. -No support for some kind of temporary id: In JPA/Hibernate, the id for an object is "null" until you flush it to the database, so if you need to reference a particular object instance from the user interface... there is plain no way to do it, you have to "save it first" to get a primary key. Those are my main disagreements with the way I have to work with JPA/Hibernate... will switching to Cayenne help me with those? And if it works... here is a crazy idea... what if you guys developed a wrapper that could work on top of any JPA provider to offer a higher level EOF like API ? Regards, Francisco -- View this message in context: http://www.nabble.com/Coming-from-EOF%3A-Cayenne-vs-Hibernate-tp22463349p22463349.html Sent from the Cayenne - User mailing list archive at Nabble.com.
