B ITM 330 Lecture Notes - Lecture 8: Unified Modeling Language, Subtyping, Associative Entity

• School: SUNY Albany
• Department: Information Technology Management
• Course: B ITM 330
• Professor: Jakov Crnkovic

Document Summary

The diagrams in previous slides are called entity-relationship diagrams. Has-a relationships entity instance: an employee has a badge, a badge has an employee. Information engineering (ie) [james martin 1990] uses crow"s feet to show the many sides of a relationship, and it is sometimes called the crow"s foot model. Integrated definition 1, extended 3 (idef1x) is a version of the e-r model that is a national standard: unified modeling language (uml) is a set of structures and techniques for modeling and designing object-oriented programs (oop) and applications. Associative entities are attributes that are associated with the relationship between two entities rather than with either of the two entities themselves: a new entity is then created to, link the two original entities, hold the attributes. If exclusive, the supertype relates to at most one subtype. If inclusive, the supertype can relate to one or more subtypes.