3.1 CSC 102 Introduction to Information Systems Databases

3.2 Data & Information Data –a single piece of information –text, numbers, images, sounds that don’t have mean much Information –meaning given to data, interpreted data Programs –collections of instructions for manipulating data

3.3 Data & Information (cont) Data: –Bill –15000 –10 Information: –Bill makes $15,000 per year and only works 10 months per year

3.4 Database A structured collection of related data about one or more subjects An information set with a structure Refers to computerized systems

3.5 Database Basic Concepts Files –A collection of records related to a subject –E.g.: customer list, product list, price list Record –Information about a single item –E.g.: the product XYZ Field –The individual data item held for each record –E.g.: the product number, name

3.6 Models/Types of Databases Flat files –Simple database structure –all the information is stored in plain text files –one database record per line Relational model –the first formal database model –Data is held in many cross-referenced files –Reduces duplication –Relational database management system (RDBMS)

3.7 Relationships Relations between the entities of the database One-to-many One-to-one Many-to-many (not allowed in Access)

3.8 One-to-many

3.9 Many-to-many

3.10 Benefits of Databases Speed Easiness of use Can store and manipulated lots of data Easy sorting, searching and selecting data Formatting options Sharing of information with others Reduce duplication

3.11 Benefits of Access Works well with other MS products (Excel, Word, PowerPoint, Visio) Easy for beginners –Can start developing db immediately –Familiar look and feel as other MS-windows applications

3.12 Main Components - Access Tables –collect and store data Queries –questions you ask about your data Forms –method of input, edit or view information – record by record Reports –method for viewing and printing information – multiple records (Use Access help for definitions)