Persistence in Java
Over the past years, I have gathered experience in the field of persistence abstraction in Java, using concepts such as EJB 2.0, Hibernate, JPA and home-grown ones. They seemed to me to have a steep learning curve and lots of complexity. In addition, as a big fan of SQL, I also thought that many abstraction models provide too much abstraction over SQL, creating concepts such as "criteria", "predicates", "restrictions" that are very good concepts, but not SQL.
The general idea of persistence abstraction in Java seems to be based on the Object-relational model, where RDBMS are somehow matched with the OO world. The ORM-debate has always been an emotional one, as there does not seem to exist a single solution that suits everyone - if such a solution can even exist.
My personal preference of how to avoid ORM-related problems is to stick to the relational world. Now the choice of data model paradigm should not be the topic of discussion as it is a personal preference, or a matter of what data model best suits a concrete problem. The discussion I would like to start is around my very own persistence tool called jOOQ. I designed jOOQ to provide most of the advantages modern persistence tools have:
- A Domain Specific Language based on SQL
- Source code generation mapping the underlying database schema to Java
- Support for many RDBMS
Adding some features that few modern persistence tools have (correct me if I'm wrong):
- Support for complex SQL - unions, nested selects, self-joins, aliasing, case clauses, arithmetic expressions
- Support for non-standard SQL - stored procedures, UDT's, ENUMS, native functions, analytic functions
Please consider the documentation page for more details: http://www.jooq.org/learn.php. You will see that a very similar approach is implemented in Linq for C#, although Linq is not exclusively designed for SQL.
Now, having said that I'm a big fan of SQL, I wonder whether other developers will share my enthusiasm for jOOQ (or Linq). Is this kind of approach to persistence abstraction a viable one? What are the advantages / disadvantages you might see? How could I improve jOOQ, and what's missing in your opinion? Where did I go wrong, conceptually or practically?
Critical but constructive answers appreciated
I understand that the debate is an emotional one. There are many great tools out there that do similar things already. What I am interested in is critical but constructive feedback, based on your own experience or articles you may have read.