Chapter 4 Building Conceptual Data Models

Making inheritance links mutually exclusive

When an inheritance link is mutually exclusive between children, one occurrence of the parent entity cannot be matched to more than one child entity.

This information is for documentation only and has no impact in generating the PDM.

To make an inheritance link mutually exclusive:

1. Double-click the inheritance link in the diagram to display the inheritance link property sheet.
   
2. Select the Mutually Exclusive Children check box.
3. Click OK.
   
   The mutually exclusive inheritance links display an X on the half-circle symbol.
   

The inheritance link shown above is mutually exclusive. It means that an account is either checking or savings, never both.

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