Computer Science 101

Database Concepts

Database

• Collection of related data

• Models real world “universe”

• Reflects changes

• Specific purposes and audience

Database Management System

• Complex software system

• General purpose - not specific to one domain

• Commercial product

• Vary from personal database managers (Access) to large, corporate systems (Oracle, SQL Server).

Relational Model

• Used by most popular database systems

• Data is stored in tables consisting of rows and columns.

• Rows correspond to individual entities.

• Columns correspond to properties or attributes of the entities.

Major Components - Definition

• Definition: – Define the tables and the kinds of data in the

tables– Specify constraints on the data– Define relationships that exist between entities– Define indexes to be built for searching, etc.– Can be done with Data Definition Language or

with some kind of “wizard” or “tool”.

Major Components - Tables

Major Components - Queries

• Searching for data that meet specified conditions

• Results can combine data from various tables and contain specified attributes

• Can be done with a Query Language or using special helper tools provided

• Query can be stored for future use

Alsos Browse

for People

People Browse Query

Major Components - Forms

• Create Forms for – Data Entry– Update– Queries

• Can involve multiple related tables

• Can involve “action” buttons, computed values, etc.

Alsos Book Form

Major Components - Reports

• Printable reports

• Related data from various tables

• Sections and subsections

• Summary data based on sections, subsections, etc.

Alsos Book Report