This topic contains a solution. Click here to go to the answer

Author Question: What are the roles of aggregation and association in relational database? What will be an ideal ... (Read 54 times)

notis

  • Hero Member
  • *****
  • Posts: 596
What are the roles of aggregation and association in relational database?
 
  What will be an ideal response?

Question 2

Design patterns are usually classified based on the type of the problems that they address.
 
  Indicate whether the statement is true or false



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

fraziera112

  • Sr. Member
  • ****
  • Posts: 356
Answer to Question 1

To map to a relational database, aggregation must be flattened into association; that is, the relational model is flat: tables do not own each other and are not composed of each other. This means that aggregation and composition relationships must be changed to association to map to tables. The task is not complicated: the table for the aggregate class provides the primary key, the tables for aggregating classes implement the foreign keys, and the multiplicity stays the same.

Answer to Question 2

TRUE




notis

  • Member
  • Posts: 596
Reply 2 on: Jul 7, 2018
Wow, this really help


nothere

  • Member
  • Posts: 324
Reply 3 on: Yesterday
Excellent

 

Did you know?

Amphetamine poisoning can cause intravascular coagulation, circulatory collapse, rhabdomyolysis, ischemic colitis, acute psychosis, hyperthermia, respiratory distress syndrome, and pericarditis.

Did you know?

The term bacteria was devised in the 19th century by German biologist Ferdinand Cohn. He based it on the Greek word "bakterion" meaning a small rod or staff. Cohn is considered to be the father of modern bacteriology.

Did you know?

Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.

Did you know?

Multiple sclerosis is a condition wherein the body's nervous system is weakened by an autoimmune reaction that attacks the myelin sheaths of neurons.

Did you know?

Patients who cannot swallow may receive nutrition via a parenteral route—usually, a catheter is inserted through the chest into a large vein going into the heart.

For a complete list of videos, visit our video library