Relationships are reasons of relevance to the business for associating two entities from one or two entity types. In the following example, we have Care Providers and Patients. Is there a reason why the business wants to associate specific entities from Care Provider with specific entities of Patient? If the business wanted to know that Dr. Smith treated John Doe, then we would need a relationship to depict this business relevance.
Relationships have two memberships, one each from the point of view of the participating entity types. From the point of view of the Care Provider, Each Care Provider treats Patient. From the point of view of the Patient, Each Patient is treated by Care Provider. To read a relationship, start with either of the two entities and proceed clockwise around the diagram.
The diagramming convention for relationships is a line between the associated entity types. The naming convention for relationship memberships is typically the active and passive forms of a verb.
What is the relationship between entity type Golfer and entity type Scoring Record?
|
Copyright © 2013 CA.
All rights reserved.
|
|