Generating NHibernate Persistent Objects

NHibernate is a port of the Hibernate Core for Java to the .NET Framework. It handles persistent POCOs (Plain Old CLR Objects) to and from an underlying relational database.

PowerDesigner supports NHibernate through an extension file that provides enhancements to support all the common .NET idioms, including association, inheritance, polymorphism, composition, and the collections framework are supported. NHibernate allows you to express queries in its own portable SQL extension (HQL), as well as in native SQL, or with Criteria and Example objects.

To enable the NHibernate extensions in your model, select Model > Extensions, click the Attach an Extension tool, select the NHibernate file (on the O/R Mapping tab), and click OK to attach it.

• NHibernate Options
  To set the database connection parameters and other NHibernate options, double-click the model name in the browser to open its property sheet, and click the NHibernate tab.
• Defining Class Mappings
  There are two kinds of classes in NHibernate:
• Defining Association Mappings
  NHibernate supports one-one, one-to-many/many-to-one, and many-to-many association mappings. The mapping modeling is same with standard O/R Mapping Modeling. However, NHibernate provides special options to define its association mappings, which will be saved into <Class>.hbm.xml mapping file. PowerDesigner allows you to define standard association attributes like Container Type class, role navigability, array size and specific extended attributes for NHibernate association mappings.
• Defining Inheritance Mappings
  NHibernate supports the two basic inheritance mapping strategies:
• Generating Code for NHibernate
  Before generating code for NHibernate, you must have NHibernate 1.0.2 or higher installed.