Tutorial for Designer/2000
and Developer/2000

Lesson 5, page 4

  1. The next step will be to create the attributes for the various entities. In order to do that:

  2. The attributes will be shown on the entity. (See Figure 5.15). (The # sign to the left of an attribute indicates that the attribute is the identifier/key for the entity).

    Figure 5.15

    Figure 5.15: The completed E-R diagram

    You have now successfully created your first simple E-R diagram.

  3. Save your work by File -> Save Diagram As ERDSRS . DO NOT EXIT OUT OF THE E-R DIAGRAMMER.

Some Additional Conventions in Oracle Designer/2000

  1. Attributes do not appear as ellipses connected to the entity by a line but appear as text within the rounded rectangle representing the entity (see below).

  2. Relationships are not represented using a diamond.

  3. Subtypes are not represented using the ISA relationship but by creating entities that are subtypes within the box representing the supertype.

Additional Conventions

Lesson Summary:

In this lesson you learned:

Next we will learn how to convert this E-R model to a physical database design. For this, proceed to lesson 6.

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