B ITM 330 Study Guide - Midterm Guide: Database, Relational Model, Microsoft Access
19 Oct 2017
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Document Summary
Chapter 1 explains why databases are used, what their components are, and how they are developed. Students will learn the purpose of databases and their applications, as well as how databases differ from and improve on lists in spreadsheets. Database is a collection of related tables and other structures. is used to help people keep track of things. 4 components of database system- users database application dbms database a row with incomplete values, called null values. null value means a missing value. is ambiguous. It can mean that no value is appropriate, that a value is appropriate but has not yet been chosen, or that a value is appropriate and has been chosen but is unknown to the user. Eliminate by requiring attribute values. relational model emerged as the leading solution to solving list problems. A relational database contains a collection of separate tables. A table holds data about one and only one theme in most circumstances.
