Relationships and Domains › Relationships in the Logical Model › Add an Exclusive Subtype Relationship

Add an Exclusive Subtype Relationship

Add an exclusive subtype relationship in a logical model so that an attribute in the subtype entity can derive its value from only one subtype entity.

To add an exclusive subtype relationship

1. Click on the ERwin Toolbox.

   The cursor changes.

2. Click the parent entity in the relationship, then click the first child entity.

   The relationship is created.

3. Click on the ERwin Toolbox, click the symbol, then click a child entity.

   A subtype is added. Repeat for each child entity that you want to add as a subtype.

4. Right-click the symbol, and then click Subtype Properties.

   The Subtype Properties dialog opens.

5. Select the Exclusive option and click OK.

   The exclusive subtype relationship is added and the Subtype Properties dialog closes.