Reg algebra girija-projection

100 %
0 %
Information about Reg algebra girija-projection

Published on March 11, 2014

Author: nbgirija



projection, selection, relational algebra, database-all the slides are downloaded from various websites

R1 := πL (R2)  L is a list of attributes from the schema of R2.  R1 is constructed by looking at each tuple of R2, extracting the attributes on list L, in the order specified, and creating from those components a tuple for R1.  Eliminate duplicate tuples, if any. PROJECTION

2 Example: Projection milk milk_type price Al-marai Full_Fat 2.50 Al-marai Refresh 2.75 Lancor Full_Fat 2.50 Lancor Refresh 3.00 Prices := πmilk,price(Sells): milk price Al-marai 2.50 Al-marai 2.75 Lancor 2.50 Lancor 3.00 Sells

Display the name column only Display name column whose salary is greater than 80000 Projection – exercise 1

Projection – exercise 1 solution

PROJECTION-exercise 2 solution

PROJECTION-exercise 3 Display Surname,Firstname Display Department,head

PROJECTION-exercise 3 solution

PROJECTION-exercise 4 Display all the Acc-no, title of the book

PROJECTION-exercise 4 Solution

PROJECTION-exercise 5 Display name, dept of the EMP

PROJECTION-exercise 5 Solution

Display age, weight from person PROJECTION-exercise 6

PROJECTION-exercise 6 solution

Add a comment

Related presentations