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

Explain the difference between drop and delete, Explain the Difference betw...

Explain the Difference between DROP and DELETE DELETE deletes one or more than one tuples of a particular relation from the database. DROP is employed to remove a table from th

Explain the aggregation implies concurrency, Explain the Aggregation implie...

Explain the Aggregation implies concurrency Concurrency actually is: This in objects can be identified by the way they change state. Present objects can change state independen

What is serialization and where it is used, What is serialization? Where it...

What is serialization? Where it is used and why?  Serialization is a basic term used for mechanisms which enable objects and object structures to be converted into portable for

What are the disadvantages of file-processing system, What are the disadvan...

What are the disadvantages of file-processing system?  Ans: The Disadvantages of File-Processing System a. Data redundancy and inconsistency - Data redundancy means not nece

Create a database model, Submit the table creation statements (including co...

Submit the table creation statements (including constraints) for the Database Model. Submit them all in a single script file. Also submit a document explaining what test data yo

What is a view in sql and when can views be updated, What is a view in SQL?...

What is a view in SQL? When can views be updated? A view is a virtual table which consists of columns from one or more tables. Through it is same to a table; it is stored in

Sorting-stacks, 1. Identify the comparisons and exchanges made to sort the ...

1. Identify the comparisons and exchanges made to sort the following array using the selection exchange sort technique. Note: you may not need all columns. Ori

What is called block-level striping, What is called block-level striping? ...

What is called block-level striping? Block level striping stripes blocks across many disks. It treats the array of disks as a large disk, and provides blocks logical numbers

What are the benefits of ooa technology, What are the benefits of OOA techn...

What are the benefits of OOA technology? Using OOA technology can produce many benefits, such as:  i) Reusability of code  ii) Productivity is gained through direct mappi

Relationship, What is multiple relationship ?

What is multiple relationship ?

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