Relational model: Difference between revisions

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The '''relational model''' ('''RM''') for [[database]] management is an approach to managing data using a structure and language consistent with [[first-order logic|first-order predicate logic]], '''first described in 1969''' '''by [[Edgar F. Codd]]'''.<ref>{{Citation | title = Derivability, Redundancy, and Consistency of Relations Stored in Large Data Banks | first = E.F | last = Codd | publisher = IBM | series = Research Report | year = 1969}}.</ref><ref name= "codd1970">{{cite journal|last= Codd |first= E.F |year=1970|title=A Relational Model of Data for Large Shared Data Banks | series = Classics | url= http://www.acm.org/classics/nov95/toc.html |journal=[[Communications of the ACM]] |volume= 13 |issue= 6 |pages= 377–87 |doi= 10.1145/362384.362685}}</ref> In the relational model of a database, all data is represented in terms of [[tuple]]s, grouped into [[relation (database) |relation]]s. A database organized in terms of the relational model is a [[relational database]].

[[File:Relational Model.svg|thumb|280px|Diagram of an example database according to the relational model<ref name="USDT01">{{Citation | format = [[Portable document format |PDF]] | url = http://knowledge.fhwa.dot.gov/tam/aashto.nsf/All+Documents/4825476B2B5C687285256B1F00544258/$FILE/DIGloss.pdf | title = Data Integration Glossary | place = [[United States of America |US]] | publisher = Department of Transportation | date = August 2001}}.</ref>]]