Data Base

www.lib.ku.edu/instruction Database Design Practical Database Design for relative Database counsel Systems Overview A smallish background and terminology: What is a comparative informationbase? What is a ancient light upon? What is a foreign appoint? Things to know just about designing a entropybase: 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 relative Database Management System Collection of information organized in tables Tables argon in any case relations Tables argon constructed and associated to each other by dint of shared palm viridity 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 c ut selective information quickly, and help to ensure accuracy 9/19/07 3 primitive and strange list Fields Primary Key Primary key fields essential be queer and cannot contain a futile value. Each table should rescue a primary key field. Concatenated keys: using more than angiotensin-converting enzyme field as a primary key field.

Foreign Key: Fields in a table that extend to to the primary key in another table The data in this field must hardly match data 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 attend by which we efficiently organize data to get hold of these goals: ! Eliminating tautology Ensuring data is stored in the correct table Eliminating need for restructuring database when data is added. Five trains of normal form In frame to achieve one level of normal form, each previous level must be met Third normal form is ample for approximately typical database applications. 9/19/07 5 scratch line Normal hit (1NF) There are no reiterate or duplicate...If you necessity to get a full essay, order it on our website: OrderEssay.net

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