Explain algorithm of er to relational mapping, Database Management System

Assignment Help:

Explain algorithm of ER To Relational Mapping ?

ER-to-Relational Mapping Algorithm:

1) Step 1: Mapping of regular entity types: For each strong entity type E, form a relation T which involves all the easy attributes of a composite attribute.

2) Step2: Mapping of weak entity types: For each weak entity type W along with owner entity type E, create relation R and involve all easy attributes (or simple components of composite attributes) of W as attributed of R. In addition, involves as foreign key attributes of R, the primary key attribute (s) of relation(s) which correspond to the owner(s) and the partial key of the weak entity type W, if any.

3) Mapping of relationship types: form a relation R, for relationship along with primary keys of participating relations A and B as foreign keys in R. Further to this, any attributes of relationship become an attribute of R also.

4) Mapping of multivalued attributes: For every multilvalued attribute A, form a new relation R. This relation R will involve an attribute corresponding to A, plus primary key attribute K-as a foreign key in R-of the relation which represents the entity category or relationship type that has A as an attribute.


Related Discussions:- Explain algorithm of er to relational mapping

Differentiate between primary and secondary storage, Differentiate between ...

Differentiate between Primary and secondary storage? Primary and secondary storage - Primary storage device stores the data temporarily. Primary storage is commonly used thro

Illustrate the collaboration and relationship diagram, Illustrate the colla...

Illustrate the collaboration and relationship diagram A collaboration is the society of interfaces, classes and other elements which work together to provide some cooperative b

Processing arrays, 1. A company wants a report containing a breakdown of pa...

1. A company wants a report containing a breakdown of payroll by department. Input, which should be stored in 3 parallel arrays, includes each employee's department number, hourly

Why were functional methods fashionable in early days, Why were functional ...

Why were functional methods fashionable in early days? These are inspired directly by computer architecture and thus popular among computer scientist in early days. The divisio

Database for online assignment system, i want to database for online assign...

i want to database for online assignment submission system

Create records in a table - data structures, In this exercise you will crea...

In this exercise you will create ten records, each containing the following fields: student name, class:  Freshman, Sophomore, Junior or Senior, Major:  Liberal Arts or General Sci

What is a database, What is a database? Database - Basically in simpl...

What is a database? Database - Basically in simple terms A database is a collection of inter related data and/or information stored so which it is available to several users

Pl/SQL, I need solution of the question posted at http://www.expertsmind.c...

I need solution of the question posted at http://www.expertsmind.com/questions/sql-query-for-testing-triggers-and-stored-procedures-30140149.aspx

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd