hi,
could any one pls give the difference between the hql and ejbql in a point wise difference and which among them is better and why ? hope this question is related to this topic

hope that some one can help ans my query

thanks in advance
balabeera

They look very alike. If you know ejbql, you shouldn't have problems learning HQL. In my opinion, HQL is far more elegant and powerful than EJBQL.

A word of caution: you souldn't use HQL all the time... just when things get too hard to do it with other methods. First, you should rely in your domain logic connectors. Then, on the Criteria Object. Only after this, you should use HQL.

Bye

-> means has influenced

EJBQL -> HQL -> EJB3QL

I think you priority list are wrong or at least not precise.

One should use what best fits the job - and the "level of hardness" in a problem doesnt define which query mechanism to use.

Domain level connectors are like navigating a graph and it quickly get to damn slow if you spread out your navigation...(because you are hitting the database multiple times).

Explicitly defining what you want to fetch via HQL *or* Criteria is often the most efficient way to do things....and wether you like HQL before Criteria or the other way around is totally up to the developers style and needed functionallity.

(I prefer HQL over Criteria in H2, but with the new projection API and result transformers in Hibernate 3 i'm starting to use Criteria more - but i still most often use HQL)

could u people be specific and tell me what exactly the difference between the hql and ejbql and pls give me a point wise difference between the two

balabeera:
I think you should see de documentation about HSQL... you'll notice the differences faster than by any other method.

As for the navigation, criteria and HQL, I did not expressed quite clear my thoughs. You're right in that the only involved factor is not the difficulty of the operation. But if you use HQL all the time, you gradually start to lose the advantages that a good graph gives you. Although HQL is great, it still is a SQL-like language. And you always can go back at later time and tweak some precise place where the performance is not all that you want and put some HQL instead of a graph connection. But, most of the time, graph navigation will be fine and it implies no extra programming effort.

Bye !!