Chapter 8 O/R Mapping Modeling

Overview

PowerDesigner not only supports object-oriented modeling and data modeling, but also supports O/R Mapping modeling between OOM and PDM objects.

The following table lists object mappings in these two model types:

OOM Element	PDM Element
Domain	Domain
Class (only if the Persistent and Generate checkboxes are selected in the class property sheet)	Table
Attribute Column (only if the Persistent checkbox is selected in the attribute property sheet)	Column
Identifier	Identifier
Association	Reference or table
Association class	Table with two associations between the end points of the association class
Generalization	Reference

You can define mappings between these two model types in any of the following ways:

Top-down approach – define classes, generate database schema and O/R mapping
Bottom-up approach – reverse engineer a database or define new database schema, generate classes and O/R mapping
Meet-in-the-middle – manually define O/R mapping using the visual mapping editor