JPA, Hibernate, EclipseLink, ...

The following articles are available:

• JPA Gotchas

  A list of pitfalls to watch out for when starting out with JPA.

• JPA Composite Key Variants

  The JPA 2.0 specification allows a number of different variants to specify composite primary keys. Each one has advantages and disadvantages as well as limitations which are detailed in this article.

• Relationships to Non-Primary Key Columns

  The JPA specification doesn't support relationships to non-primary key columns. At the same time however, it doesn't disallow them, effectively making them a non-portable, optional feature. The details are laid out in this article along with a test case using Hibernate 3.6 and EclipseLink 2.2.

• JPA Provider Bug Parade

  A list of potential and factual bugs I reported to Hibernate and EclipseLink. I also keep this list to track their progress.