Using Multiple Tables

In TopLink, it is possible to spread classes across two or more tables. In the advanced tutorial, the Employee class is stored in multiple tables: although most information is in the EMPLOYEE table, salary information is stored in the SALARY table.

To map the Employee class to multiple tables:

1. Select the Employee descriptor in the Navigator pane.

2. Click the Multi-Table Info tab in the Editor pane.

   If the Multi-Table info tab is not visible, right-click the Employee descriptor and choose Set Advanced Properties >  Multi-Table Info from the pop-up menu.

3. In the Additional Tables pane, click Add and add the SALARY table.

4. In the Associated Via pane select Primary Key and in the Primary Key Table Reference pane, select Primary Keys Have Same Names.

   Figure B-36 Multi-Table Info Tab

   
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5. 
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   Click Save on the toolbar or choose File >  Save Project to save the project.