MySql or mapper for java, mysql mapper, GNA JORM Java Object Relational Mapper OR mapper, Java,java, or-mapper, object relational mapper, object bridge, Open source, Andreas Marochow, sourceforge, java database,java persistence layer, object database

Java Object Relational Mapper for MySQL

GNA - JORM Java Object Relational Mapper is another OR-Mapper for Java Pojos (Plain Old Java Objects).

Why another OR-Mapper ?
It is different to other OR-Mappers, because it is:

fast it is very fast (without using caches), because it's simple (see PolePosition benchmark ).

save it don't uses any caches, if you commit, everything is written to the database, immediately !
it is designed for multy-threaded environments ( it is thread-save ).
it can handle recursive linked object-graphs correctly.

lightweight the main functionality is kept in 15 Java-Classes ( the whole jar is about 100k ).
at runtime no additional jars are needed (ok, you need a jdbc-driver).

simple to use there is no mapping description needed.
it handles whole object-graphs. You only have to attach/detach the root-object to the session.
it supports transactions so you can commit() or rollback() whole units of work.

easy to understand every class (even a derivate) is mapped to one table in the database, you see your objects.
as rows and your attributes as columns. Inheritance is not spread over many tables.

economically it supports lazy loading , by using Hollowobjects (you work with your classes, no proxys !)
it has build in session pooling.
it is free under license GPL .

flexible you can provide a dedicated mapping description (a single mapping.xml).
it supports linked objects via Java-Interfaces transparently.
use embeded Objects to melt smaler objects into the parent-tables.

convenient OO-Path-Querys like getObjects( new Query(Address.class, "country->currency->isoCode", Query.LIKE, "EUR") .
the schema-checker tool will help you keep your database compatible to your classes .

fast	it is very fast (without using caches), because it's simple (see PolePosition benchmark ).
save	it don't uses any caches, if you commit, everything is written to the database, immediately ! it is designed for multy-threaded environments ( it is thread-save ). it can handle recursive linked object-graphs correctly.
lightweight	the main functionality is kept in 15 Java-Classes ( the whole jar is about 100k ). at runtime no additional jars are needed (ok, you need a jdbc-driver).
simple to use	there is no mapping description needed. it handles whole object-graphs. You only have to attach/detach the root-object to the session. it supports transactions so you can commit() or rollback() whole units of work.
easy to understand	every class (even a derivate) is mapped to one table in the database, you see your objects. as rows and your attributes as columns. Inheritance is not spread over many tables.
economically	it supports lazy loading , by using Hollowobjects (you work with your classes, no proxys !) it has build in session pooling. it is free under license GPL .
flexible	you can provide a dedicated mapping description (a single mapping.xml). it supports linked objects via Java-Interfaces transparently. use embeded Objects to melt smaler objects into the parent-tables.
convenient	OO-Path-Querys like getObjects( new Query(Address.class, "country->currency->isoCode", Query.LIKE, "EUR") . the schema-checker tool will help you keep your database compatible to your classes .