Applying Top-Down Approach

In order to apply well-defined O/R Mapping strategies, PowerDesigner provides default transformation rules for model generation. We will introduce these rules in detail in the following sections. You can also customize transformation using persistence settings and generation options.

1. Create the OOM, defining object-oriented model elements, persistent classes, inheritance links and associations etc, to describe the static features of your model domain.
2. Define transformation settings to apply transformation rules. See Basic transformations.
3. Define generation options.
4. On the General tab, specify the DBMS type, the name and code of the generated PDM. You can also click the Update existing Physical Data Model radio button to update the existing PDM. This option allows you to do round trip generation.
   
   
5. On the Detail tab, click the O/R Mapping checkbox, in order for PowerDesigner to automatically generate O/R Mapping between the PDM and the OOM. You can also specify table prefix that will apply to all the generated tables.
   
   
6. Select the OOM objects that you want to transform into PDM objects on the Selection tab.

• Basic Transformation
  There are two types of classes:
• Association Transformation
  Association defined between entity classes will be transformed into reference keys or reference tables. Associations with Value type classes as target or source will be ignored.
• Inheritance Transformation
  PowerDesigner supports three mapping strategies for inheritance persistence:

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Created October 7, 2009. Send feedback on this help topic to Sybase Technical Publications: pubs@sybase.com