Extending Uml Class Diagrams to Capture Additional Association Semantics

The Unified Modeling Language (UML) has gained much popularity in recent years. In UML, class diagrams provide notations for modeling the semantics of the structural relationships, or associations, that occur between objects. Object Relationship Notation (ORN) provides another declarative scheme that permits the semantics of such associations to be modeled and then defined to a Database Management System (DBMS). ORN has been incorporated into entity-relationship diagrams, a prototype object DBMS, and a database modeling tool called the ORN Simulator. Both ORN and UML allow for cardinality constraints to be defined for both ends of an association using compatible notations; however, only ORN allows the relative bindings between related objects to be specified based on these constraints. Bindings provide important semantics relevant to the deletion of related objects within a complex object and the destruction and modification of internal linkages. Here, we explain the binding notations of ORN and show how they can be added to UML class diagrams in order to capture additional association semantics.