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:
- Expand the Data section of the palette
in the diagram editor.
- Add a new generalization to an existing entity:
- 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.
- 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.
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.