The Data in the Repository

The Repository contains data expressed as objects and relationships, along with their respective property values. The following figure shows some typical data for employees, projects, and subprojects.

The preceding figure includes all the typical kinds of data you'll find in the Repository, so you can use it to understand the classes in the Repository's object model. In the figure, you can see instances of the following classes:

• The Repository class

  The Repository class describes the Repository itself. The entire figure represents an instance of the Repository class.

• The RepositoryObject class

  Each instance of the RepositoryObject class describes an object. The figure shows 12 objects, one of which is the root object; each instance is a dot.

• The ReposRoot class

  The ReposRoot class describes the root object. Each Repository includes exactly one root object.

• The Relationship class

  Each instance of the Relationship class describes an association between two objects. The figure shows 15 relationships; each relationship is an arrow.

The figure also includes the following classes:

• The RelationshipCol class

  Each instance of the RelationshipCol class describes a set of similar relationships. The items in a relationship collection must be similar to each other in two ways:

  • First, every item must be a relationship that conforms to the same relationship type as every other item.
    
    
  • Second, there must be one object that is common to all relationships in the collection. That object must play the same role for all relationships in the collection.

  One relationship collection in the figure is the set of Mike's assignments to subprojects. In the figure, this relationship collection appears as a pair of arrows emerging from the dot representing Mike.

• The TargetObjectCol class

  Each instance of the TargetObjectCol class describes a set of objects. For example, one set of objects is the set of subprojects that Mike works on; the set contains two items.