Example of equijoin, Database Management System

Example:

Consider the following relations:

ROLLNO

NAME

ADDRESS

COURSE_ID

100

Kanupriya

234, Saraswati Vihar.

CS1

101

Rajni Bala

120, Vasant Kunj

CS2

102

Arpita Gupta

75, SRM Apartments.

CS4

STUDENT

Course

COURSE ID

COURSE_NAME

DURATION

CS1

CS1

BCA

3yrs

CS2

MCA

3yrs

CS3

M.Sc.

2yrs

CS4

B.Sc.

3yrs

CS5

MBA

2yrs

 

 

 

If we want to show name of all the students with their course details then natural join is used in the following method:

STUDENT     COURSE

Resultant relation will be as follows:

If R2                    R3= R1 ÷ R2                      If R2                       R3= R1 ÷ R2

Student

ROLLNO

NAME

ADDRESS

COURSE_ID

COURSE_NAME

DURATION

100

Kanupriya

234, Saraswati

Vihar.

CS1

BCA

3yrs

101

Rajni Bala

120, Vasant Kunj

CS2

MCA

3yrs

102

Arpita

Gupta

75, SRM

Apartments.

CS4

B.Sc.

3yrs

 

 

 

 

 

There are some other types of joins like outer joins.

Posted Date: 3/6/2013 5:55:34 AM | Location : United States







Related Discussions:- Example of equijoin, Assignment Help, Ask Question on Example of equijoin, Get Answer, Expert's Help, Example of equijoin Discussions

Write discussion on Example of equijoin
Your posts are moderated
Related Questions
what is entity in database system?

What is the need of a log in a DBMS? Briefly describe the various types of records that are normally present in a log.            Ans:  The system log, which is generally writt

What is multiple relationship ?

Create Student DB and perform delete operation? STUDENT (name, student#, class, major) COURSE (course name, course#, credit hours, department) SECTION (section identifier, co

Project Description: This is going to be a School portal to handle each activities in school such as, School fees payment, online registration and every other payment, course re

Explain the Static or conservative Two Phase Locking: Static (or conservative) Two Phase Locking: In this type of scheme, all the data items are locked earlier than any opera

What is disadvantage of multiple inheritances? There is potential ambiguity if the similar variable or method can be inherited from more than one superclass.eg: student class m

Smart Alex Catering Sevice (SACS) is a company offering top class catering staff  for prestigious events.  The company employs approximately 200 hourly paid contact staff - chefs,


Primary index A primary index is a file that has a sorted series of records having two columns: a block address for that key field in the data file; and the ordering key field.