UML Data Models From An ORM (Object-Role Modeling) Perspective. Data Modeling at Conceptual Level

摘要

This paper provides an overview of Object-Role Modeling (ORM), a fact-oriented method for performing information analysis at the conceptual level. It provides both a graphical and textual languages and a procedure which guides the use of the languages. The article is structured in two main parts. The first part presents an overview of ORM along a real example, while the second part of the article makes a comparison between ORM and UML from the conceptual data modeling perspective. This paper examining data modeling in the Unified Modeling Language (UML) from the perspective of Object Role Modeling (ORM). It provided some historical background on both approaches, identified design criteria for modeling languages, and discussed how object reference and single-valued attributes are modeled in both. It compared UML multi-valued attributes with ORM relationship types, and discussed basic constraints on both, as well as instantiation using UML object diagrams or ORM fact tables. This third issue compares UML associations and related multiplicity constraints with ORM relationship types and related uniqueness, mandatory role and frequency constraints. It also contrasts instantiation of associations using UML object diagrams and ORM fact tables.