Women in Technology

Article:		Hibernate Your Data
Subject:		Is it the best?
Date:		2004-01-16 04:01:08
From:		fabiolourencetti
Is Hibernate the best free ObjectRelationalMapping tool?

Showing messages 1 through 2 of 2.

• Check out OJB
  2004-01-16 13:53:19  jimothy [View]
  
  
  I prefer OJB, which its authors say stands for ObJectRelationalBridge (you have to use your imagination).
  
  The main reason I prefer OJB is its object-oriented querying mechanism, versus the HQL of Hybernate. If crafting SQL strings is a hassle, why is crafting HQL strings any better?
  
  The example from the article, Find Orders within a price range, would look like this in OJB:
  
  

  
  
  broker = PersistenceBrokerFactory.defaultPersistenceBroker();
  
  broker.beginTransaction();
  
  
  
  Double lowPrice = new Double(args[0]);
  
  Double hiPrice = new Double(args[1]);
  
  
  
  Criteria criteria = new Criteria();
  
  criteria.addGreaterThan("priceTotal", lowPrice);
  
  criteria.addLessThan("priceTotal ", hiPrice);
  
  
  
  QueryByCriteria query = new QueryByCriteria(Order.class, criteria);
  
  Collection results = broker.getCollectionByQuery(query);
  
  
  
  broker.commitTransaction();
  
  

  
  
  Adding additional criteria is simple. For instance, we may also want to query on orders with a certain product name, but only if the user entered such criteria on a form. With HQL, this would involve sometimes akward string concatenation, which is one of the things I like an O/R tool to help me escape! In OJB, you'd just have to write code like:
  
  

  
  
  if (productName != null && productName.length() > 0)
  
  {
  
     criteria.addEqual("product.name", productName);
  
  }
  
  

  
  
  If you're familiar with Enterprise Object Framework (EOF, part of WebObjects), this style will be familiar to you.
  
  OJB also supports ODMG and it's Object Query Language, as well as a reference JDO implementation. Frankly, I wish they'd drop both and focus on just the PersistenceBroker API (used above). A more focused approach would allow them to get OJB out of release candidate status and to a final release.
  
  Check it out!
  
  

• Is it the best?
  2004-01-16 11:29:31  rmcodnough [View]
  
  
  I have worked with Castor, JDO, and Entity beans and so far I have found Hibernate to be the most sttaight forward and well documented project out there. It's also pretty darn snappy too. Combined with XDoclet, things get even better. I pretty much use XDoclet and Ant to generat the Hibernate mapping files and create my SQL Schema. Works like a champ. Highly recommended.