Do You Know How Hackers Steal Your Credentials? Join us and Skyport Systems to learn how hackers steal your credentials and why Active Directory must be secure to stop them. Thursday, July 13, 2017 10:00 A.M. PDT
Course Of The Month
3 days, 11 hours left to enrollBecome a Premium Member and unlock a new, free course in leading technologies each month.
Solved
I have a question according to the relational model database
Posted on 2011-03-23
In terms of the relations shown below, what is the appearance of the realtion RESULT after executing each of thesre instructions:
X relation Y relation
U V W RS
A Z 5 3 J
B D 3 4 K
C Q 5
RESULT <- PROJECT W from X
X relation Y relation
U V W RS
A Z 5 3 J
B D 3 4 K
C Q 5
RESULT <- PROJECT W from X
[X]
Welcome to Experts Exchange
Add your voice to the tech community where 5M+ people just like you are talking about what matters.
- Help others & share knowledge
- Earn cash & points
- Learn & ask questions
2
5 Comments
Projection is an operation to retrieve some of the relation values.
Project W From X should lead you to get the W column as a result.
...and please try to get your homework done by yourself, as you obviously should have this "Projection" information in some reference books...
Project W From X should lead you to get the W column as a result.
...and please try to get your homework done by yourself, as you obviously should have this "Projection" information in some reference books...
Active today
hi,
BigSchmuh is right. Simply read the basic theory:
http://en.wikipedia.org/wiki/Relational_Database#Relational_operations
"The projection operation extracts only the specified attributes from a tuple or set of tuples."
BigSchmuh is right. Simply read the basic theory:
http://en.wikipedia.org/wiki/Relational_Database#Relational_operations
"The projection operation extracts only the specified attributes from a tuple or set of tuples."
thanks. Of course I am doing my homework myself always and this homework was made by ,yself too!!!:) It's just attemp how site is working as I am new here. Of course in all other my quetsions I will follow main rules and if I'd like to ask something from experts according my homework I will do it just in special events if some qeustions are are really very contradictory, I have doubts and I reallyneedhelp of experts to solve my problem.
Featured Post
![[Webinar] How Hackers Steal Your Credentials](https://filedb.experts-exchange.com/files/public/2017/5/20/3315d9d8-8110-4d52-be94-a5aacdd83e4b.png)
Question has a verified solution.
If you are experiencing a similar issue, please ask a related question
Azure Functions is a solution for easily running small pieces of code, or "functions," in the cloud.
This article shows how to create one of these functions to write directly to Azure Table Storage.
This article shows the steps required to install WordPress on Azure.
Web Apps, Mobile Apps, API Apps, or Functions, in Azure all these run in an App Service plan.
WordPress is no exception and requires an App Service Plan and Database to install
Using examples as well as descriptions, step through each of the common simple join types, explaining differences in syntax, differences in expected outputs and showing how the queries run along with the actual outputs based upon a simple set of dem…
Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…
Suggested Courses
Earn Certification
HTML5 Specialist - Certification
Free withPremium
Course of the Month3 days, 11 hours left to enroll
Earn Certification
Administering Microsoft SQL Server 2012 Databases (Exam 70-462)
$79.00$71.10
630 members asked questions and received personalized solutions in the past 7 days.
Join the community of 500,000 technology professionals and ask your questions.