Top-Down: Mapping Classes to Tables

PowerDesigner provides default transformation rules for generating physical data models from object-oriented models. You can customize these rules with persistence settings and generation options.

1. Create your OOM, and populate it with persistent classes (see Entity Class Transformation), inheritance links and associations etc, to define the structure of your model domain.
2. Select Tools > Generate Physical Data Model to open the PDM Generation Options dialog.
3. On the General tab, specify the DBMS type and the name and code of the PDM to generate (or select an existing PDM to update).
4. Click the Detail tab and select the O/R Mapping checkbox. You can optionally also specify a table prefix that will be applied to all generated tables.
   
   
   
5. Click the Selection tab and the select the OOM objects that you want to transform into PDM objects.
6. Click OK to generate (or update) your PDM.

• Entity Class Transformation
  To transform a class into a table, select the Persistent option on the Detail tab of its property sheet and then specify the type in the Persistent groupbox.
• Attribute Transformation
  To transform an attribute into a column, select the Persistent option on the Detail tab of its property sheet.
• Value Type Transformation
  PowerDesigner supports fine-grained persistence model. Multiple classes can be transformed into single table.
• 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 various mapping strategies for inheritance persistence. Each strategy has its pros and cons, and you should select the most appropriate one for your needs. You can also apply mixed strategies, but this may not be well supported by your persistence framework.