gtpa3m0kApplication Requester User's Guide

A Few Words about Relational Databases

Relational databases consist of a set of related tables. The tables are made up of rows and columns. In a table, a column is a vertical arrangement of information, and a row is a horizontal arrangement of information. Table 1 contains an example of a corporate telephone directory. Each row contains phone information about an employee. This information is arranged by columns. Each column is a different part of the employee information. In our example, the employee record is broken up into last name, first name, middle initial, country code, city code, phone number, employee number, and an internal time stamp value. In our example, the time stamp indicates the last time the record was updated.

Table 1. Example of a Corporate Telephone Directory

Last Name First Name Middle Initial Country Code City Code Phone Employee Number Time Stamp
Villard Jean E 33 6 555-2342 4 1991-05-04-10.30.30.123423
Martinez Juan C 52 748 555-1923 2 1991-05-04-12.30.30.345452
Durr Robert
1 914 555-1272 1 1991-05-04-16.00.12.324567
Chiba Takao
81 3 555-1625 6 1991-02-01-19.32.13.432342
Johnson Hans
49 89 555-1625 5 1990-11-21-22.45.32.875643
Stewart Mary L 44 1 555-2323 3 1991-08-08-14.14.08.847372
Stewart James J 44 1 555-2324 7 1991-03-23-15.39.59.948373