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Computer Fundamentals 2 Computer Fundamentals Introducing Computer Architecture and Databases 1 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 2 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 3 Computer Fundamentals 2 Introduction to Computer Architecture Bits and Bytes • The bit (binary digit) is the smallest unit of information on a computer • • • • • • • 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 4 Computer Fundamentals 2 Classes of Computers • Mainframe • • • • Extremely powerful Centralised Expensive e.g. servers • Minicomputers • Smaller than mainframe • Still very powerful • e.g. used in research, computer laboratories 5 Computer Fundamentals 2 Elements of a Computer Hardware Operating System Applications Software 6 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 7 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 8 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: • • • • 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 9 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? 10 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 … 11 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 12 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 13 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 14 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 15 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: • • • • Create and define the database Retrieve sets of data Manipulate / change data Maintain the database • Examples: • MS Access, SQL Server, Oracle 16 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 17 Computer Fundamentals 2 Advantages of MS Access • • • • • Easy to use Graphical User Interface Object Linking and Embedding Visual Relational Tools Extendible (Macros, Visual Basic) 18 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 19 Computer Fundamentals 2 Database components • Data • description of data • includes tables (entities) • fields (attributes) • relationships between the tables 20 Computer Fundamentals 2 Database components Tables – grids of rows and columns which hold the data Queries – manipulate the data (sorting / calculating / selecting) 21 Computer Fundamentals 2 Access Database Components Forms – enter / view /edit the data (User Interface) Reports – present the information VB Code – automate / extend the application 22 Computer Fundamentals 2 Naming Conventions • In Access prefixes should be used to distinguish between different objects • • • • Tables – tbl (e.g. tblCustomer) Queries – qry (e.g. qryTotalCost) Forms – frm (e.g. frmMenu) Reports – rpt (e.g. rptInvoice) 23 Computer Fundamentals 2 Any Questions? 24