« previous next »

Author Question: Which of the following is not true about representing subtypes in a relational database design? ... (Read 19 times)

craiczarry

  • Hero Member
  • *****
  • Posts: 527
on: Jul 7, 2018
Which of the following is not true about representing subtypes in a relational database design?
 
  A) One table is created for the supertype and one for each subtype.
  B) All of the attributes of the supertype are added to the subtype relations.
  C) The key of the supertype is made the key of the subtypes.
  D) An instance of the supertype may be related to one instance each of several subtypes.

Question 2

When running an SQL query that uses NOT EXISTS, the NOT EXISTS keyword will be true if ________.
 
  A) any row in the subquery meets the condition
  B) all rows in the subquery meet the condition
  C) no row in the subquery meets the condition
  D) any row in the subquery fails to meet the condition


Jody Vaughn

  • Sr. Member
  • ****
  • Posts: 344
Reply #1 on: Jul 7, 2018
Answer to Question 1

B

Answer to Question 2

C


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

Walt Disney helped combat malaria by making an animated film in 1943 called The Winged Scourge. This short film starred the seven dwarfs and taught children that mosquitos transmit malaria, which is a very bad disease. It advocated the killing of mosquitos to stop the disease.

Did you know?

Each year in the United States, there are approximately six million pregnancies. This means that at any one time, about 4% of women in the United States are pregnant.

Did you know?

The term pharmacology is derived from the Greek words pharmakon("claim, medicine, poison, or remedy") and logos ("study").

Did you know?

Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.

Did you know?

When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).

An activation barrier, representing the transition state An activation barrier, representing the transition state
Masamichi Udagawa and Sigi Moeslinger, Antenna Design, Knoll Toboggan Chair. Masamichi Udagawa and Sigi Moeslinger, Antenna Design, Knoll Toboggan Chair.
Java Software Solutions: Foundations of Program Design Java Software Solutions: Foundations of Program Design
Starting Out with Programming Logic and Design Starting Out with Programming Logic and Design
Importance of Considering Gestalt Principles in Product Design (1 of 2) Importance of Considering Gestalt Principles in Product Design (1 of 2)
Midsagittal section indicating locations of true and false pelves Midsagittal section indicating locations of true and false pelves
Video: Coronary Heart Disease Animation

For a complete list of videos, visit our video library