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 ∏

(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 .

Posted Date: 3/6/2013 5:52:30 AM | Location : United States

Ask an Expert

Related Discussions:- Project operation, Assignment Help, Ask Question on Project operation, Get Answer, Expert's Help, Project operation Discussions

Write discussion on Project operation
Your posts are moderated

Write your message here..

Related Questions

Determine the types of methods for retrieving rows in python, Describe the ... Describe the two types of methods for retrieving rows in Python? Fetchone()- Returns the next row as a sequence Fetch all()- Returns the entire result set like a strin

Failures and recovery, Failures and Recovery In practice various things... Failures and Recovery In practice various things might occur to prevent a transaction from completing. Recovery methods are used to bring database, which does not satisfy consi

What are wait-for-graphs, What are wait-for-graphs?Give the algorithm to co... What are wait-for-graphs?Give the algorithm to construct a wait-for-graph from a given schedule of transactions? How can deadlocks be detected from wait-for-graphs?   Ans:  The

Balance transfer, Scenario 1: Power goes out after the first instruction. ... Scenario 1: Power goes out after the first instruction. What happens?

Three level architecture of dbms-logical architecture, Three Level Architec... Three Level Architecture of DBMS or Logical DBMS Architecture The logical architecture defines how data in the database is perceived by users. It is not deals with how the da

What is an object design, What is an object design? Object design is a ... What is an object design? Object design is a very interactive method, which decides the relationship among objects, classifies operations on classes, determines overall system

For known, What are the function of DBA? What are the function of DBA?

What is primary index, Primary Index In primary index, there is a one-t... Primary Index In primary index, there is a one-to-one relationship among the entries in the index table and the records in the major table. Primary index can be of two types:

Provide examples of different types of time and date formats, Provide Examp... Provide Examples of different types of Time and Date formats.  It's most common store dates using a dash (-) as a colon (:)and the delimiter as the time delimiter. The given fo

Primary key, The primary key is selected from the The primary key is selected from the