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

OLD HOME POLICIES, Write an sql statement to find what is the percentage of...

Write an sql statement to find what is the percentage of home policies which are from the state of Arizona out of all Home policies by Policy Value.

MANAGEMWNT OF PRINCILES AND TECHNIQUES., HOW TO SOLVE THE LP Problems by si...

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

Dataware house(job scheduling strategy), Define a job scheduling strategy t...

Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pictori

Draw entity-relationship diagram of database, Read the description below a...

Read the description below and draw an Entity-Relationship diagram for it. You must use the symbols described in the course materials. This database will help the Parents Assocc

Accessing information permissions users, Accessing information about permis...

Accessing information about permissions to all users- Object level permissions: With the use of data dictionary you can see the permissions to user. Let us get the table name fro

What are the acid properties?, Question 1 What are the advantages of DBMS ...

Question 1 What are the advantages of DBMS approach in managing data? Question 2 What are the services provided by a database system Question 3 List and briefly describe

Draw an e-r diagram and convert it to a relational schema, In an organizati...

In an organization several projects are undertaken. Each project can employ one or more employees. Each employee can work on one or more projects. Each project is undertaken on the

Database errors, Database Errors: An error is said to have occurred if the ...

Database Errors: An error is said to have occurred if the implementation of a command to manipulate the database cannot be successfully finished either due to inconsistent data or

Structure of distributed database, Structure Of Distributed Database: A di...

Structure Of Distributed Database: A distributed database system haves of a collection of sites, each of which keeps a local databases system. Every site is able to process local

What is the initial step for object-oriented designing, What is the initial...

What is the initial step for object-oriented designing The initial step for object-oriented designing is object modeling. Before we go into deep about object modeling first of

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