Databases


 * 3.7 Databases**


 * Introduction**

Databases lie **//at the heart of most IT systems//** whether in businesses, organizations or other institutions. Databases **//enable organizations to maintain accurate and comprehensive records//**. In order to appreciate the role that databases play, the ITGS student must //**h****ave an understanding of how they work**//, which can only be gained from the //**design and creation**// of basic relational databases as well as by //**examining how databases**// //**are used in specified scenarios**// (for instance, schools, retail stores, online shopping, online reservations). The increasing use of databases **//raises a range of social impacts and ethical issues//** such as the rights of individuals with respect to the storage and potential sale of their personal data or the ease of data mining and data matching. Students are expected to discuss these issues and, where appropriate, __//evaluate possible//__ __//solutions.//__ **Possible scenario** A vet requires information about pet owners and their pets. The ITGS student must be able to develop an original IT solution to meet the vet’s needs. This knowledge should be acquired through a practical activity where the student creates a (minimum) three-table relational database (first normal form only) that uses queries to interrogate the data, forms to enable the easy input printed information as required.

A **database** consists of an organized collection of data for one or more uses, typically in digital form. One way of classifying databases involves the type of their contents, for example: bibliographic, document-text, statistical. Digital databases are managed using database management systems, which store database contents, allowing data creation and maintenance, and search and other access.
 * WHAT IS A DATABASE?**

- A short video to show how information is stored in a database - Fields and Records - Relational Database. media type="youtube" key="7rSJbe2cWY4?fs=1" height="268" width="336"
 * WHAT DOES A DATABASE LOOK LIKE?**

A database management system (DBMS) consists of [|software] that operates databases, providing storage, access, security, backup and other facilities. Database management systems can be categorized according to the [|database model] that they support, such as [|relational] or [|XML], the type(s) of computer they support, such as a server cluster or a mobile phone.
 * WHAT DO YOU USE TO CREATE DATABASES?**

Examples of DBMS include -
 * MySQL,
 * PostgreSQL,
 * [|Microsoft Access,]
 * SQL Server,
 * [|FileMaker,]
 * Oracle,
 * RDBMS,
 * dBASE,
 * Clipper,
 * FoxPro

**IT concepts to address in this topic** • Table • Field, data types, key field/primary key, secondary key • Record • Flat-file database, relational database, normalization • Database management system • Specialized databases: for example, web databases, online encyclopedias
 * Database organization**

• Data validation: data types, range check, check digit, field size, input mask, drop-down list • Queries: for example, searching, sorting, filtering, use of Boolean operators (AND, NOT, OR) • Data entry form • Report generation • Macros • Transfer of data between databases and other applications
 * Functions**

**Data storage and access** • Data integrity, reliability, redundancy • Data matching, data mining • Database security

//• Table // //• Field, data types, key field/primary key, secondary key // //• Record // //• Linking tables to create a relational database // //• Data maintenance: changing, editing, deleting records // //• Queries: for example, searching, sorting, filtering, use of Boolean operators (AND, NOT, OR) // //• Data entry form // //• Report generation // //• Creating and editing simple macros // //• Mail merge //
 * Practical database techniques (see above for definition)**

Social and ethical issues related to information systems and databases
Articles related to Databases
 * acknowledgment of data sources - //RELIABILITY//
 * the freedom of information act - //PRIVACY//
 * privacy principles - //PRIVACY//
 * accuracy of data and the reliability of data sources - //ACCURACY and RELIABILITY//
 * access to data, ownership and control of data - //AUTHORIZATION and AUTHENTICATION//
 * new trends in the organisation, processing, storage and retrieval of data such as data warehousing and data-mining - //DIGITAL DIVIDE//
 * //[|2010, the year that privacy died?]// - An article talking about the privacy issue regarding databases.
 * //[|US Embassy cables: Browse the database]// - Use our interactive guide to discover what has been revealed in the leak of 250,000 US diplomatic cables.