As architects, we often need to decide on what OR mapping tool to use. I came across this article on JavaLobby that compares iBatis, Hibernate and JPA.
Snippets from the article:
iBATIS is best used when you need complete control of the SQL. It is also useful when the SQL queries need to be fine-tuned. iBATIS should not be used when you have full control over both the application and the database design, because in such cases the application could be modified to suit the database, or vice versa. In such situations, you could build a fully object-relational application, and other ORM tools are preferable. As iBATIS is more SQL-centric, it is generally referred to as inverted -- fully ORM tools generate SQL, whereas iBATIS uses SQL directly. iBATIS is also inappropriate for non-relational databases, because such databases do not support transactions and other key features that iBATIS uses.
Hibernate is best used to leverage end-to-end OR mapping. It provides a complete ORM solution, but leaves you no control over queries. Hibernate is an ideal solution for situations where you have complete control over both the application and the database design. In such cases you may modify the application to suit the database, or vice versa. In these cases you could use Hibernate to build a fully object-relational application. Hibernate is the best option for object-oriented programmers who are less familiar with SQL.
JPA should be used when you need a standard Java-based persistence solution. JPA supports inheritance and polymorphism, both features of object-oriented programming. The downside of JPA is that it requires a provider that implements it. These vendor-specific tools also provide certain other features that are not defined as part of the JPA specification. One such feature is support for caching, which is not clearly defined in JPA but is well supported by Hibernate, one of the most popular frameworks that implements JPA. Also, JPA is defined to work with relational databases only. If your persistence solution needs to be extended to other types of data stores, like XML databases, then JPA is not the answer to your persistence problem.
iBATIS does not provide a complete ORM solution, and does not provide any direct mapping of objects and relational models. However, iBATIS provides you with complete control over queries. Hibernate provides a complete ORM solution, but offers you no control over the queries. Hibernate is very popular and a large and active community provides support for new users. JPA also provides a complete ORM solution, and provides support for object-oriented programming features like inheritance and polymorphism, but its performance depends on the persistence provider.