Dear All,
  It is well known in every developer that one of the most hard tasks
when working on a large project is the database management. It becomes
even harder when the specifications change from time to time forcing
amendments of the database structure. It is even harder if one decides
to work with prepared statements for increased performance and security
and this is also the case in OpenTox.
  For these reasons, here in NTUA, we decided to tackle the issue of
database creation/management in a more systematic and generic way by
developing an O.R.M. (Object Relational Mapping) Java tool called
DeciBell. In DeciBell, Java classes are related to relational database
entities automatically and in a transparent way as far as the background
operations are concerned. So, on the one hand, non-expert users can work
on Java code exclusively while an expert one will be able to focus on
more algorithmic aspects of the problem they try to solve rather than
with trivial database management issues. In contrast to the existing ORM
programs (Hibernate, Smyle, etc), DeciBell does not require any
configuration files or composite query structures, but only a proper
annotation of certain fields of the classes. This annotation is carried
out by means of the Java Annotations which is a modern trend in Java
programming. Among its supported features, DeciBell supports: 

* Annotation of primary and foreign keys explicitly.
* One-to-many and Many-to-Many relations are automatically produced from
Java Collections, Lists and Sets.
  Relational tables and Auxiliary weak entities are automatically
generated and used.
* Self-referencing Java classes (e.g. a User which has a friend-User)
are automatically correlated to self-referencing tables.
* Objects of unspecified internal structure are serialized as XML and
stored in the database from where they can be easily retrieved.
* Multiple primary keys are supported
* The four essential database operations are supported using prepared
statements (SELECT, INSERT, DELETE, UPDATE).
* There is the ability to work with multiple databases from within the
same project. One can also connect to the same database using two
distinct users.
* Support for the Derby JDBC server but we are also planning to provide
support for the MySQL server.
* DeciBell uses reflection only on startup. All necessary Fields and
Constructors are backed up to be used directly when needed. No
reflective operations are used on runtime.
* DeciBell works exclusively with Prepared Statements for increased
security and performance. 
* The beta version of DeciBell will come with support for Java hierarchy
relational mapping, that is the Java hierarchical structure is reflected
in the database.

   The alpha version (release for testing) of DeciBell is available at
http://github.com/hampos/DeciBell and we would be glad if you try it and
send us some comments. The results from the first 35 JUnit tests and 
all initial small-scale experiments are quite encouraging for us and we
will keep providing more features. These results will be presented in a
workshop which is part of the annual FOSS conference here in Athens.

We have also started using DeciBell in our services and indeed it
simplifies the source code (5000 lines deleted already due to DeciBell)
and facilitates the development!


Best Regards,
Pantelis Sopasakis
Charalampos Chomenides