Project operation, Database Management System

Assignment Help:

The PROJECT operation

The project operation is used to choose the records with specified attributes as discarding the others based on some related criteria. This is denotes as ∏

1913_relation.png

(Relation) Example:

Consider the relation PERSON. If you want to display only the names of persons then the project operation will be used as follows:

Π Name (PERSON)

The resultant relation will be as follows:

NAME

Sanjay Prasad

Sharad Gupta

Vibhu Datt

Note: -

1) Π ( Π (R))= Π (R)

As long as have attributes in .


Related Discussions:- Project operation

Define radix conversion method, Define Radix conversion method  One cle...

Define Radix conversion method  One clever way to transform binary numbers to BCD notation (binary-coded decimal) is the "double dabble algorithm". It can be adapted to transfo

What is meant by software and hardware raid systems, What is meant by softw...

What is meant by software and hardware RAID systems? RAID can be executed with no change at the hardware level, using only software modification. Such RAID implementations are

What is a checkpoint, What is a checkpoint? List the operations to be perfo...

What is a checkpoint? List the operations to be performed by the system when a checkpoint is to be taken. What does the recovery system do if there is a crash? There is large n

Give an example of object representation, Give an example of Object Represe...

Give an example of Object Representation  For illustration, consider the implementation of a social security number within an employee object that is shown in Figure. The soci

Assignments, i have assignments I don''t have time to finish because of wo...

i have assignments I don''t have time to finish because of work and other assignments, can you help with this? All are from the book Darabase design, application development and a

What is multiplicity in the associations, What is multiplicity in the assoc...

What is multiplicity in the associations? Give an example to explain multiplicity? Multiplicity in association indicate number of objects participate in any relationship. For

What is dml compiler, What is DML compiler? DML Compiler: Translates DM...

What is DML compiler? DML Compiler: Translates DML statements in a query language within low level instructions understandable through the query evaluation engine. Attempts to

Explain retrieval in qbe, Explain retrieval in QBE? Retrieval in QBE : ...

Explain retrieval in QBE? Retrieval in QBE : A "GUI" for expressing queries. Based on the Domain Relational Calculus (DRC) Actually invented before GUIs. Very co

Explain the structured decomposition, Differentiate between the object orie...

Differentiate between the object oriented decomposition and the structured decomposition? Process-oriented (structural) decomposition divides a complex process, function or tas

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