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

Write short notes on tuple relational calculus, Write short notes on tuple ...

Write short notes on tuple relational calculus. The tuple relational calculation is anon procedural query language. It defines the desired information without giving a particul

Problem about data mining for business intelligence, Do the 11.1 11.1 Cre...

Do the 11.1 11.1 Credit Card Use. Consider the following hypothetical bank data on consumers’ use of credit card credit facilities in Table 11.3. Create a small worksheet in Exce

BI, (a) Why did SAP introduce the extended star schema?

(a) Why did SAP introduce the extended star schema?

What are the comparison operator in sql, What are the comparison operator i...

What are the comparison operator in SQL?  Comparison operator in SQL are =, LIKE and BETWEEN

Employee elation with information, Consider a database application that dea...

Consider a database application that deals with an Employee relation with information such as SIN, name, data of birth (DOB), and DID (the ID of the department at which the employe

multiple-mode locks, Multiple-mode locks : It offers two locks: exclusive ...

Multiple-mode locks : It offers two locks: exclusive locks and shared locks. But why do we require these two locks? There are a lot of transactions in the database system that neve

What is the aim of logical schema, What is the aim of logical schema ? ...

What is the aim of logical schema ? The main motive of the logical schema is to ensure the portability of procedures and models on various physical schemas at runtime.

Explain how the binary tree, QUESTION (a) Give two advantages of using ...

QUESTION (a) Give two advantages of using Linked List as compared to arrays. (b) (i) You are working as programmer at the Orange Mauritius branch. You have been asked to cre

Conversion of er diagram to relational database, Conversion of entity sets:...

Conversion of entity sets: I)   For  every  strong  entity  type  E  in  the  ER  diagram,  we  make  a  relation  R containing all the easy attributes of E. The relation R pri

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