7.4 Relationships and Entities
Relationship rules are defined based on entity type. Remember, entities are defined before relationships. The Logical Modeler only allows meaningful relationships to be defined for a given entity type as the logical model can be built into a physical database. For example, a Parent/Child relationship can be defined only between Data, Variant and External entities.
These are the default relationship rules:
|
Relationship Type |
Source Entity Type |
Target Entity Type |
|
Parent/Child |
Data, Variant or External |
Data |
|
Join |
Data or Variant |
Data, Variant or External |
|
Variation |
Data |
Variant |
|
Include |
Data |
Conceptual |
For more information about how to define Source and Target entities, refer to 7.3 Source and Target Entities and 7.7.1 Create a Relationship.
Also see 7.2 Relationship Rules.
Note: Abstractions are not entities. They are objects used to group entities. Abstraction cannot be used in relationships.