Creating generalization sets in a diagram

Use the diagram editor in the workbench to create generalization sets.

Before you begin

Before you can create a generalization set, you must create a new diagram or open an existing diagram. The diagram must contain at least one entity that you want to use to define a generalization set.

About this task

By default, when you create a generalization, the generalization is added to the generalization set under the supertype entity. If the generalization that you draw is the first generalization for the entity, a new generalization set is added to the entity.
Note: If you want to assign the generalization to a different generalization, you must ensure that the Enable generalization set prompt option is selected on the Logical Data Model page of the Preferences window.

The best way to understand generalization sets and generalizations is to use the diagram editor. Use the diagram editor to create and define generalization sets and generalizations.

Procedure

To create a generalization set:

  1. Expand the Data section of the palette in the diagram editor.
  2. Add a new generalization to an existing entity:
    1. Select the Generalization object. The Generalization object is highlighted in the palette, and the icon changes as shown in the following figure:
      Figure 1. The function is disabled as you mouse over blank diagram areas or non-entity objects in the diagram editor.The function is disabled
    2. Select the subtype entity of the generalization set on the diagram, then drag the cursor to a blank space in the diagram to create a new supertype entity. You can also drag the cursor to an existing entity that you want to be the supertype entity. When you mouse over an entity, the arrow changes as shown in the following figure:
      Figure 2. The function is enabled as you mouse over an entity.The function is enabled

Results

The supertype entity is created, or an existing entity is updated to be considered a supertype entity. The generalization set is created in the Data Project Explorer under the supertype entity. The generalization is created in the Data Project Explorer under the subtype entity.

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