Example of relational operations, Database Management System

Assignment Help:

Consider the relation PERSON. If you want to display details of persons having age less than or equal to 30 than the select operation will be used as follows:

σ AGE <=30 (PERSON)

The resultant relation will be as shown:

PERSON_ID

NAME

AGE

ADDRESS

2

Sharad Gupta

30

Pocket 2, Mayur

Vihar.

 

 

 

Note:

1)   Select operation is commutative; i.e.,

σ (R)) = σ (R))

Therefore, series of select can be applied in any order

2) More than one condition can be applied using Boolean operators OR & AND etc.


Related Discussions:- Example of relational operations

Discuss the three level architecture of dbms, PRINCIPLES OF DATABASE 1....

PRINCIPLES OF DATABASE 1. State the following terms: a) Database b) Database Management System c) Entity d) Attribute e) Relationship 2. Discuss the Three Level Architecture

What is a relationship called when it is maintained entities, What is a rel...

What is a relationship called when it is maintained between two entities? A relationship is called Binary relationship when it is maintained between two entities.

Develop a database design , A practice called Perfect Pets provides private...

A practice called Perfect Pets provides private health care for domestic pets throughout America. This service is provided through various clinics located in the main cities of Ame

Data warehouse, 1) Define a job scheduling strategy that will meet business...

1) 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 pict

Explain the components of database system in details., Explain the compone...

Explain the components of Database System in details.

What are the uses of odbc, What are the uses of ODBC? Under what circumstan...

What are the uses of ODBC? Under what circumstances we use this technology? ODBC expose database capabilities within a standardized way to the application programmer by an ap

What are the time stamps associated with each data item, What are the time ...

What are the time stamps associated with each data item? W-timestamp (Q) denotes the largest time stamp if any transaction that implemented WRITE (Q) successfully. R-timesta

Advantages of Observation Methods, Advantages of Observation  Methods: ...

Advantages of Observation  Methods: Bailey has pointed  out four  advantages of observation: 1. Superior in Data  Collection  on Non Verbal Behavior: When  a person  a opi

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

What do you understand by raid, What do you understand by RAID? Explain RA...

What do you understand by RAID? Explain RAID Level 4 and Level5? RAID - It is stands for Redundant Array of Inexpensive Disks (as named by the inventor), or alternatively Re

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