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

Erd, er diagram on cosmetics.

er diagram on cosmetics.

Explain deadlock detection and recovery, Explain Deadlock detection and rec...

Explain Deadlock detection and recovery Deadlock Detection - A deadlock is said to take place when there is a circular chain of transaction, every waiting for the release of a

Lossless-join decomposition, Lossless-Join Decomposition   Let us sh...

Lossless-Join Decomposition   Let us show an intuitive decomposition of a relation. We require a better basis for deciding decompositions since intuition may not always be r

Why is database redesign necessary, Why is database redesign necessary? ...

Why is database redesign necessary? Database redesign is essential for two reasons. First, redesign is essential both to fix mistakes made during the initial database design. S

Concept of foreign key, Fundamentals of Database Management 1. Explai...

Fundamentals of Database Management 1. Explain the concept of Foreign Key. How a foreign key differs from a Primary Key? Can the Foreign Key accept nulls? 2. With a necess

What is cross product, What is Cross Product? Simply Cross product is B...

What is Cross Product? Simply Cross product is Binary Operator

Explain the advantages of dbms over file oriented system, Explain the main ...

Explain the main advantages of DBMS over File Oriented System ?

ER-diagram, The State of NewYork certifies firefighters throughout state an...

The State of NewYork certifies firefighters throughout state and keep track all of them, as well as of the state’s fire departments. Each fire department has unique department numb

Benefits of using a relational database management system, Question 1: ...

Question 1: a) What is the difference between a non-impact and impact printer? b) Which type of printer is generally used in a supermarket to print your receipt? Describe

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