BBG 101 Lecture Notes - Lecture 17: Data Management, Database, Relational Model
13 Aug 2020
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Document Summary
To build a history of business events. To keep track of customers, sales, orders, payment receipts, suppliers, tax information, transaction data, general company knowledge, employees, external information (government, industry, research) A collection of data organised to meet users" needs. Comprised of database, dbms, and application programs. Field (smallest: name, number, or combination of characters that describes some aspect of an object. Record (bigger: collection of related fields. File (larger: collection of related records. Database (largest: collection of integrated and related files. Generalised class of people, places, or things for which data is collected, stored, and maintained. For example, employee number or last name. Field in a record used to identify the record. In the relational model, all data elements are placed in two-dimensional tables or relations. As long as tables share at least one common element, those relations can be linked to produce useful information. Projecting (to be what you want only) Joining (to process data into useful information)
