A relationship connects two associated data entities. The relationship between two entities can often be expressed with a verb. For example, the relationship between the DEPARTMENT entity and the EMPLOYEE entity might be expressed with the verb phrase BELONGS TO, since an employee belongs to a department in an organization.
Representing the relationship between two entities
The relationship between two entities is shown with a diamond. The name of the relationship is specified inside the diamond.
No hard-and-fast rule exists for determining data relationships for an organization. Data relationships depend on the requirements of the organization. The concept of marriage, for example, could be viewed as an entity type or a relationship between two people, depending on how the data was viewed.
|
Copyright © 2014 CA.
All rights reserved.
|
|