Reflexive Relationships

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Multiple objects belonging to the same class may have to communicate with one another. This is shown on the class diagram as a reflexive association or aggregation. Role names rather than association names typically are used for reflexive relationships.

CREATING A REFLEXIVE RELATIONSHIP IN RATIONAL ROSE

1. Select the Association (or Aggregation) icon from the toolbar.

2. Click on the class and drag the association (or aggregation) line outside the class.

3. Release the mouse button.

4. Click and drag the association (or aggregation) line back to the class.

5. Enter the role names and multiplicity for each end of the reflexive association (or aggregation).

A reflexive relationship is shown in Figure 6-8.

Figure 6-8. Reflexive Relationship

The reflexive relationship in Figure 6-8 may be read in the following ways:

• One Course object playing the role of Prerequisite is related to zero or more Course objects.

• One Course object is related to zero or more Course objects playing the role of Prerequisite.

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