What is E-R model, Database Management System

E-R Model

This data model is based on real world that consists of basic objects named entities and of relationship among these objects. Entities are illustrated in a database by a set of attributes. An Entity - Relationship model is an abstract way to define a database. It generally starts with a relational database, which loads data in tables. Some of the data in these tables point to data in other tables - for instance, your entry in the database would point to various entries for each of the phone numbers that are yours. The ER model would define that you are an entity, and each phone number is an entity, and the relationship between the phone numbers and you is 'has a phone number'. Diagrams prepared to design these relationships and entities are called E-R diagrams or entity-relationship diagrams.

 

955_ER Model.png

Posted Date: 7/30/2012 1:46:07 AM | Location : United States







Related Discussions:- What is E-R model, Assignment Help, Ask Question on What is E-R model, Get Answer, Expert's Help, What is E-R model Discussions

Write discussion on What is E-R model
Your posts are moderated
Related Questions

Natural Join : It is the similar like Equi join except one of the duplicate columns is removed in the result table. The natural join is the most usually used form of join operation

gyan gurukul is a software company that provides software related solution.

The cross-section of twisted pair The cross-section of each and every strand of the twisted pair is π/4 square mm. A 10-km length of this type of material, with two strands per

Modify a sequence: ALTER SEQUENCE SEQSS INCREMENT 2 MAXVALUE 3000;   Removing a sequence: DROP SEQUENCE SEQSS;

Control as Concurrent Tasks The expression control as simultaneous task means applying control for those events of object which can happen simultaneously. An object can be imp

What is advantage of two-way association? Two-way association advantages are following: a) Independent of the classes. b) Useful for existing predefined classes that are

HOW TO SOLVE THE LP Problems by simplex method?z=x1+-3x2+2x3


how to write tables and drow E-R diagrams for hosiptal management system and how to normalize and cardinalities?