Data Base

www.lib.ku.edu/instruction Database Design Practical Database Design for relative Database counseling Systems Overview A smallish background and terminology: What is a relational informationbase? What is a ancient light upon? What is a foreign account? Things to know just about designing a informationbase: The standardisation adjoin and how/why social function it Relating tables Types of relationships 9/19/07 2 © 2007 Instructional Services at KU Libraries, The University of Kansas www.lib.ku.edu/instruction relational Database Management System Collection of information organized in tables Tables argon in any case relations Tables atomic number 18 constructed and associated to each other by dint of shared palm greens palm Fields are besides columns or attributes A set of attributes comprises a record Records are also rows or tuples Tables are related through common fields designated as primary and foreign keys Allow us to find, update, and cut selective information quickly, and help to ensure accuracy 9/19/07 3 primitive and outside(prenominal) confab Fields Primary Key Primary key fields essential be comical and cannot contain a futile value. Each table should meet a primary key field. Concatenated keys: using more than brain field as a primary key field. Foreign Key: Fields in a table that refer to the primary key in another table The entropy in this field must hardly match entropy contained in the primary key field. 9/19/07 4 © 2007 Instructional Services at KU Libraries, The University of Kansas www.lib.ku.edu/instruction What is Normalization? The care for by which we efficiently organize data to light upon these goals: Eliminating verbiage Ensuring data is stored in the correct table Eliminating need for restructuring database when data is added. Five aims of normal form In locate to achieve one level of normal form, each previous level must be met Third normal form is capable for approxima! tely typical database applications. 9/19/07 5 prototypic Normal hit (1NF) There are no restate or duplicate...If you necessity to get a full essay, order it on our website: OrderEssay.net

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