Understanding Your Data Model › Using Relations › Describing and Using CA 2E Relations › Examples of Using Defined as Relation

Examples of Using Defined as Relation

Example 1: Defining a Single Entity

Let us say that a rose is a rose, declared with the following relations:

FIL         Rose    REF     Known by        FLD     Any other name  CDE

FIL  Rose    REF     Has     FLD     Petals          TXT

FIL  Rose    REF     Has     FLD     Thorns          NBR

FIL  Rose    REF     Has     FLD     Rose Type       STS

This will automatically result in the following additional relation:

FIL        Rose    REF     Defined as      FIL     Rose    REF

Example 2: Defining Several Entities (Top-down)

The Defined as statement constitutes the most basic way of declaring an entity to exist. If you are creating a new model working top down, you may first declare all the entities that you think will be required to define your model. Example:

FIL Company   REF       Defined as      FIL     Company         REF

FIL Division  REF    Defined as      FIL     Division                REF

FIL Product   REF    Defined as      FIL     Product         REF

FIL Customer  REF    Defined as      FIL     Customer                REF

There must be a Defined as relation for every CA 2E file. If you make a reference to a non-existing file, a Defined as statement is created automatically for the file.

In practice, you seldom need to enter a Defined as statement explicitly, unless you choose to define the entities in your model before using them in any other relation.