COIS 1010H Lecture Notes - Lecture 4: Database, Management System, Data Type
Document Summary
Datum: is a single piece of information, represents an attribute of an object. So we know which hockey cards, stamps, movies we own. Maybe we make lists of what we are looking for. Applications which are designed to store information in a format which facilitates asking questions about the data: these are called database management systems (electronic format) Database: a collection of related data stored in a manner so it can be retrieved as needed. Database management system: used to create, maintain, and access databases. Fields (columns: single category of data to be stored in a database (name, tele number) Records (rows): collection of related fiends in a database. Primary key: specific field that uniquely identifies the records in that table ( sin, email address,) Entities can be thought of as nouns. Attributes: characteristics of an entity (typically become fields in the entity s database table) Entity relationships: describe an association between instances in two or more entities.
