PREPARED BY: PN. SITI HADIJAH BINTI NORSANI
LEARNING OUTCOMES: Upon completion of this course, students should be able to: 1. Understand the structure of relational database. 2. List the advantages of managing data using database software. 3. Identify the basic features of database software. 4. List the difference between database and spreadsheet software.
WHAT IS A DATABASE? Collection of data organized so you can access, retrieve, and use it. Database software also called database management system (DBMS). Many people use databases to store and organized personal information such as addresses, music and video collection – much more efficient than using sheets of paper or index cards.
Database software allows you to Create forms and reports Create database Add, change, and delete data Sort and retrieve data
Basic Concepts of Relational Database Structure Every organization has data that needs to be collected, managed, and analyzed. A relational database fulfills these needs. The relational model is the basis for any relational database management system.
A relational model has three core components: A collection of objects or relations Operators that act on the objects or relations Data integrity methods. In other word, it has a place to store the data, a way to create and retrieve the data, and a way to make sure that the data is logically consistent.
Type of Databases Flat file database: Store information in one large table, and often contain duplicate information. Not flexible or efficient for storing large amounts of information Relational databases: Store information in separate tables, and enable you to use relationships to bring together information from different tables. This type is powerful and flexible, and it effectively stores large amounts of information.
Database Benefits. Databases store and manage collections of information related to a particular subject or purpose. Efficiently add, update, view and organized the information stored in a database. Can instantly locate information in a database. Create a table to hold your data, forms to enter and display the information, queries to ask questions of your data and generate reports that can be printed or distributed electronically. Useful for finding specific data in large collection of information.
Features of Database Software Part of a Database Access databases consist of objects such as tables, queries, form, report, macros, and modules.
Tables: Is a collection of related information about a specific topic. Queries: Enable you to find information of interest in a database. Form: Provide a quick way to view, enter, and modify information in a database by presenting information in an easy-to-use format. Reports: Are professional- looking documents that summarize data from your database. Macro: Saves your time by combining a series of actions into a single action Modules: Are programs created in a programming language called Visual Basic for Application (VBA).
Plan a Database Determine the purpose of the database Determine the Tables that you need Determine the Fields that you need Determine the Relations hip between Tables
Difference between Database and Spreadsheet software Most people are familiar with some kind of spreadsheet, such as Microsoft Excel. Spreadsheet are easy and convenient to use, and they may be employed by an individual much like a database is used in the enterprise. Similar to database, spreadsheets are commonly used to store information in a tabular format.
A spreadsheet can store data in rows and columns, it can link cells on one sheet to those on another sheet, and it can force data to be entered in a specific cell in a specific format. It’s easy to calculate formulas from groups of cells on the spreadsheet, create chart, and work with data in other ways.
But there are many ways in which a spreadsheet is not like a traditional database table: SpreadsheetDatabase More than one datatype can be stored in a spreadsheet column. Usually, only one datatype can be stored in a database table column. Cells in a spreadsheet can be defined as a formula, making the contents variable depending on other cells. Column in a database table have a fixed value. A spreadsheet has only the physical row number to make it unique, and no built-in way to enforce uniqueness of a given spreadsheet row. Single row of a database table are uniquely identified by a unique value. A corrupt spreadsheet cannot usually be repaired. There are many tools for repairing and recovering databases.
To be continue… Next class…