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

File handling and classes, Write the C++ program having class name studenti...

Write the C++ program having class name studentinfo, that is used to store the VU student information: This class should store your VUID, campus id, name and father name in the fol

Outer join, Outer Join: The use of Outer Join is that it still joins those...

Outer Join: The use of Outer Join is that it still joins those tuples that do not have matching values in common columns are also contained in the result table. Outer join places

#cursor, #what is cursor its uses ? Explain it

#what is cursor its uses ? Explain it

List the reg-no of vehicles owned in relational algebra, Given the followin...

Given the following relations Vehicle (Reg_no, make, colour) Person(eno, name, address) Owner(eno, reg_no) Write expressions in the relational algebra to answer the following

Primary and foreign key, Primary Key The primary key is the candidate k...

Primary Key The primary key is the candidate key that is selected by the database designer as the principal denotes of identifying entities within an entity set. The left candi

Design a query plan for distributed query, (a) Design a query plan for the ...

(a) Design a query plan for the following distributed query: An application at site B wants to compute a join of STUDENT ? Id=StudId TRANSCRIPT where STUDENT (Id,Major) is at site

Explain what is aggregation, Explain what is Aggregation ? Aggregation...

Explain what is Aggregation ? Aggregation: This is used whenever we intend to show a relationship between an entity and the relationship. There is no provision for this in th

What do you mean by atomicity and aggregation, What do you mean by atomicit...

What do you mean by atomicity and aggregation? Atomicity : Either all actions are carried out or none are. Users should not have to worry about the effect of incomplete trans

#title., WHY SHOULD NULL IN A RELATION BE AVOID AS possible?

WHY SHOULD NULL IN A RELATION BE AVOID AS possible?

Describe the major steps in the implementation process, Question: (a) ...

Question: (a) One of the steps in the five-step problem-solving model is implementation. Implementation is considered a key step in the problem-solving model. A problem may be

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