Object-Relational Mapper
NHibernate is a port of the Java Hibernate object relational mapper (ORM). ORMs translate your classes and objects into SQL commands for storing those objects and retrieving them from a relational database. Gentle.NET is another such ORM for .NET and Mono.
Code Sample
By Hans-Christian Holm (see this note).
The DLLs from nHibernate and the PostgreSQL .NET provider (Npgsql) are needed to run this sample.
The example uses a PostgreSQL server on localhost with a "person" table in the "test" database, but should work with any common database system.
nHibernate examples often use the mapping files (*.hbm.xml) as embedded resources, typically along with the business objects in a separate DLL, but I haven't figured out how to do that with booc.exe. Specifying the mapping file as a resource does not work with booc.exe.
In nHibernate, there is a contributed library (net2hbm) that allows you to use attributes to declare mappings instead of xml files, but it's rather new and undocumented right now. It's based on the similar attributing technique in (Java) Hibernate.
BooHibTest.boo:
BooHibTest.hbm.xml:
BooHibTest,exe,config:
Compile and run:
booc -r:NHibernate.dll BooHibTest.boo ./BooHibTest.exe
See Also
Gentle.NET ORM and other Database Recipes.