ICT 301- Midterm Exam Guide - Comprehensive Notes for the exam ( 20 pages long!)

• School: University of Kentucky
• Department: Information Communication Technology
• Course: ICT 301
• Professor: joekratzat

Document Summary

The entity relationship model helps transform the requirements into a formal description of the entities and relationships that appear in the database. Ex: a university database may store information about students, courses and enrollment; the student and the course are entities, while an enrollment is a relationship between a student and a course. Databases are typically used to store certain characteristics, or attributes, of the entities. An attribute may be formed from smaller parts. Ex: a postal address is composed of a street number, city, zip code, and country. Attributes are classified as composite if they"re composed of smaller parts in this way. Some attributes can have multiple values for a given entity. Ex: a customer could provide several telephone numbers, so the telephone number attribute is multivalued. Attributes help distinguish one entity from other entities of the same type. An attribute or set of attributes that uniquely identifies a particular entity is a key.