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Computer Fundamentals 2
Computer Fundamentals
Introducing
Computer Architecture and
Databases
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Computer Fundamentals 2
Aims of this course
• To give students an understanding of
basic computer architecture.
• To introduce the student to database
technology
• To provide students with the skills
needed to create personal web pages
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Computer Fundamentals 2
Learning Outcomes
• At the end of this course you will:
• Be conversant with basic database concepts
• Have a good, practical understanding of
Personal Computer Architecture
• Be able to create your own personal World Wide
Web site
• Be able to create simple web based multimedia
effects
• Be proficient in the use of simple web authoring
tools
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Computer Fundamentals 2
Introduction to
Computer Architecture
Bits and Bytes
• The bit (binary digit) is the smallest unit of
information on a computer
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Term
bit
byte
kilobyte
megabyte
gigabyte
terabyte
Symbol
b
B
KB
MB
GB
TB
Value
0 or 1
8 bits
1,024 bytes
1,024 kilobytes
1,024 megabytes
1,024 gigabytes
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Computer Fundamentals 2
Classes of Computers
• Mainframe
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Extremely powerful
Centralised
Expensive
e.g. servers
• Minicomputers
• Smaller than mainframe
• Still very powerful
• e.g. used in research, computer laboratories
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Computer Fundamentals 2
Elements of a Computer
Hardware
Operating System
Applications
Software
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Computer Fundamentals 2
Hardware vs. Software
• Hardware - The physical parts that make
up a computer
• Refers to objects that you can actually touch,
like disks, disk drives, display screens,
keyboards, printers, boards, and chips
• Software - Programs that run on a
computer
• Software exists as ideas, concepts, and
symbols, but it has no physical existence
substance
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Computer Fundamentals 2
General Applications
• Word processors (e.g. MS Word)
• Text manipulation, page/document layout
• Spreadsheets (e.g. MS Excel)
• Numeric data in rows/columns, calculation
• Databases (e.g. Access)
• Records in tables
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Computer Fundamentals 2
Operating Systems
• The basic control system for the
computer
• The most important program that
runs on a computer
• Perform basic tasks, such as:
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User
Application
Operating System
recognizing input from the keyboard,
Hardware
sending output to the display screen,
keeping track of files and directories on the disk,
controlling peripheral devices such as disk drives
and printers
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Computer Fundamentals 2
Databases
• Definition:
“A collection of logically related data and
a description of this data designed to
meet the information needs of an
organisation”
Connolly
• Does it need to be for an organisation?
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Computer Fundamentals 2
Common Uses of Databases
• Supermarket
• Bar codes on goods link to products
database. Program automatically maintains
stock levels and calculates customer’s bill
• Library
• Bar codes on books link to underlying
database
• Database can be searched by title, author
subject …
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Computer Fundamentals 2
Common Uses of Databases
• University
• Student, course and program information is
stored in a database
• Different programs handle different parts of
the system, for example - admissions, and
recording of examination results
• Different departments can share information
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Computer Fundamentals 2
File Approach
• Data collected in separate files
• Data structures dependent on particular
applications
• Duplication of data
• Multiple entry
• Different formats
• Data integrity problems
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Computer Fundamentals 2
Database Approach
• Data stored once only, minimising
duplication and inconsistency
• Data stored separately and
independently from application
programs
• Users have individualised ‘views’ of the
data
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Computer Fundamentals 2
Database Processing
Data entry
and reports
Sales
Sales application
programs
DBMS
Database
Data entry
and reports
Contracts
Database Management
System
Contracts applications
programs
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Computer Fundamentals 2
Database Management System
• DBMS: Database Management System
• A multifaceted piece of software which
constructs, expands and maintains the database
• Provides controlled access to the database
• Enables the user to:
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Create and define the database
Retrieve sets of data
Manipulate / change data
Maintain the database
• Examples:
• MS Access, SQL Server, Oracle
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Computer Fundamentals 2
Microsoft Access
• Relational Database Management
Software
• Most popular microcomputer DBMS
• Published by Microsoft
• Part of Microsoft Office Suite
• Uses the “.mdb” or “.accdb”
file extension
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Computer Fundamentals 2
Advantages of MS Access
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Easy to use
Graphical User Interface
Object Linking and Embedding
Visual Relational Tools
Extendible (Macros, Visual Basic)
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Computer Fundamentals 2
Relational Database
• Stores data in the form of related tables
• Provides a lot of flexibility and
independence
• Can be viewed in many different ways
• Easily extendible
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Computer Fundamentals 2
Database components
• Data
• description of data
• includes tables
(entities)
• fields (attributes)
• relationships between
the tables
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Computer Fundamentals 2
Database components
Tables – grids of rows
and columns which hold
the data
Queries – manipulate the
data (sorting / calculating
/ selecting)
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Computer Fundamentals 2
Access Database Components
Forms – enter / view /edit the
data (User Interface)
Reports – present the
information
VB Code – automate /
extend the application
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Computer Fundamentals 2
Naming Conventions
• In Access prefixes should be used to
distinguish between different objects
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Tables – tbl (e.g. tblCustomer)
Queries – qry (e.g. qryTotalCost)
Forms – frm (e.g. frmMenu)
Reports – rpt (e.g. rptInvoice)
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Computer Fundamentals 2
Any Questions?
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