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

Why dml is used for, Why DML is used for? DML is used to Manipulation and...

Why DML is used for? DML is used to Manipulation and processing of database. DML is provided for manipulation & processing of database. (Data stored in the database is processed

Explain concurrency control, Explain concurrency control? Concurrency ...

Explain concurrency control? Concurrency control Oracles multiversion concurrency control varies from the concurrency mechanism used by some other data base vendors. Read

Describe dynamic model, Describe Dynamic Model. The dynamic model speci...

Describe Dynamic Model. The dynamic model specifies allowable sequences of changes to the objects from an object model. It contains event trace diagrams describing scenarios. A

Describe the statement in sql which allows to change, Describe the statemen...

Describe the statement in SQL which allows to change the definition of a table? In SQL Alter statement is used to allow the changes the definition of a table.

Define dba database administrator, Define DBA database administrator? ...

Define DBA database administrator? DBA : A database administrator (DBA) is a person who is responsible for the environmental aspects of a database. In common, these involves:

Relational algebra, Consider the relation schemas as follows. works (per...

Consider the relation schemas as follows. works (person name, company name, salary); lives (person name, street, city); located in(company name, city); managers (person name

Write short notes on schema diagram, Write short notes on Schema diagram. ...

Write short notes on Schema diagram. A database schema along with primary key and foreign key dependencies can be depicted pictorially by schema diagram. Every relation appears

Conflicting operations in schedule, Conflicting Operations in Schedule: ...

Conflicting Operations in Schedule: The three simple ways of interleaved instruction implement of transactions T1 and T2. Please note that in the following tables the first col

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