Object Relationship Notation (orn) is simply a more precise notation to define the relationship with multiplicities combining UML with a unique referential action is defined. Object Relationship Notation (orn) for Database Applications: Improving the Modeling and Implementation of the Association shows how orn can be used in UML class diagrams and database definition languages (DDLs) to better model and apply the relationship & making it more productive to develop database applications. For database developers, presents many examples of the relationship was modeled using class diagrams orn-extended and show how this relationship is easily mapped to SQL orn-extended or object DDL.