Binary relationships, Database Management System

Assignment Help:

One-to-one relationship:

For every 1:1 relationship type R in the ER diagram including two entities E1 and E2 we take one of entities (say E1) preferably with total participation and add primary key attribute of one more entity E2 as a foreign key attribute in the table of entity (E1). We will also have all the simple attributes of relationship type R in E1 if any.

For instance, the DEPARTMENT relationship has been extended to contain head-Id and attribute of the relationship. Please note we will maintain information in this table of only present head and Date from which s/he is the head.

There is one Head_of 1:1 relationship among FACULTY and DEPARTMENT. We select DEPARTMENT entity having total participation and add primary key attribute ID of FACULTY entity as a foreign key in DEPARTMENT entity named as Head_ID. Now the DEPARTMENT table will be as follows:

DEPARTMENT

D_NO

D_NAME

Head_ID

Date-from

 

 

 

 

 

 

 

 


Related Discussions:- Binary relationships

Multi-list file organisation, Multi-list file Organisation Multi-list f...

Multi-list file Organisation Multi-list file organisation is a multi-index linked file organisation. A linked file organisation is a logical organisation where physical orderin

ER diagram in database, What is an ER diagram? Why is it used in Database m...

What is an ER diagram? Why is it used in Database management system (DBMS)?

Normalization, in case of functional dependencies how we get the higher nor...

in case of functional dependencies how we get the higher normal form.

Differentiate between pl/sql functions and procedures, Oracle & Distributed...

Oracle & Distributed Databases 1. Differentiate between PL/SQL functions and procedures. 2. Draw the diagram of logical structure of oracle database and explain it in brief.

Failures and recovery, Failures and Recovery In practice various things...

Failures and Recovery In practice various things might occur to prevent a transaction from completing. Recovery methods are used to bring database, which does not satisfy consi

What is null described testing for null in sql?, What is NULL? Give an exa...

What is NULL? Give an example to described testing for NULL in SQL? The NULL SQL keyword is used to represent either a missing value or a value which is not applicable in a re

RDBMS, what is RDBMS? how it works? good example.

what is RDBMS? how it works? good example.

Describe the term- state diagram, Describe the term- State Diagram Sta...

Describe the term- State Diagram State Diagram: An object could receive a sequence of the input instructions. The state of the object can differ depending upon sequence of in

Project, I have a small project that contains 3 deliverable s. I have done ...

I have a small project that contains 3 deliverable s. I have done the first one and I would like you to help me with second one

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