MIS 0855 Lecture Notes - Lecture 3: Data Modeling, Peter Chen, Database Design

• School: Temple University
• Department: Management Information Systems
• Course: MIS 0855
• Professor: Joseph C Spagnoletti

Document Summary

Mis notes - week 3, modeling data https://creately. com/blog/diagrams/er-diagrams-tutorial/ Ultimate guide to er diagrams (entity relationship diagrams: what is an er diagram, entity relationship diagram (erd) - visual representation of different entities within a system and how they relate to each other. Aka erd"s or er models: history of er diagrams, data modeling became a necessity around the 1970"s. There is no standard way to model databases or business processes: peter chen. Introduced the widely adopted er model in a paper. Supervised : cardinality and ordinality - defines relationships between entities by placing the relationship in the context of numbers. Example: in an email system, one account can have multiple contacts. There"s a number of notations used to present cardinality in er diagrams: this would be a one to many model, chen, uml, crow"s foot, bachman, how to draw er diagrams, how to create an er diagram.