Question

In relation to data modeling and ERD design, explain comprehensively what is meant by the term...

In relation to data modeling and ERD design, explain comprehensively what is meant by the term cardinality (1 mark). In relation to this same issue, how do we represent in our ERD the minimum cardinality? (1 mark)   How do we represent the maximum cardinality? (1 mark). Consider the two relationships: “a student can enrol in either 1, 2, 3, or 4 courses each semester AND a course can have student enrolments from zero to 500”. How would we represent the modality of the “student can enrol in either 1, 2, 3, or 4 courses” relationship? (1 mark). These relationships as they are described cannot be implemented in a relational database – explain why? (1 mark)

Homework Answers

Answer #1

explain comprehensively what is meant by the term cardinality (1 mark)

In respect to the ERD the terms cardinality refers to the relationship between a row of one table with an another the row of another table.

Cardinality can be one-to-one or one-to-many or many-to-many

For example : Suppose there are two tables : Student and Course

Now if a student from student table can only be enrolled in one course form the course table , it is the one-on-one cardinality.

However if the student from the student table can enroll in more than one course in the course table it is referred to as the one-to-many cardinality.

If n students from student table can apply to m number of courses from the m table , it is referred to as many-to-many cardinality

how do we represent in our ERD the minimum cardinality? (1 mark)  

The minimum carindality refers to the minimum number of the "entity-instances" that must be present in the given relationship.

It is represented as :

Zero [0] ---> Optional

One [1]----> Mandatory

The relationships are represented as :

How do we represent the maximum cardinality? (1 mark).

The maximum cardinality refers to the maximum number fo entity instances that can exist in a relationship.

They are represented as :

Consider the two relationships: “a student can enrol in either 1, 2, 3, or 4 courses each semester AND a course can have student enrolments from zero to 500”. How would we represent the modality of the “student can enrol in either 1, 2, 3, or 4 courses” relationship? (1 mark).

The modality or the minimum cardinality representation in this case will be :

Optional to Mandatory

These relationships as they are described cannot be implemented in a relational database – explain why? (1 mark)

A M:N or a one to many relationship is not supported in relational databases.

In a relational database, the ideal mode is 1:N or 1-to many and all the relationships have to be changed to the given 1:M ideal.

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Question 2 (5 Marks) What can you say about the relationships between Courses and Subject, and...
Question 2 What can you say about the relationships between Courses and Subject, and Courses and Students? Will there be any problems in creating a Relational Database from your ER diagram? If there is, then describe how you will address this and re-draw the ER diagram. Question 3 Create the DDL statements to create the tables described in your modifies ER diagram in Question 2. Question 4 In your Database you created in Question 3, assume there is a student...
Draw the Crow’s Foot database notation entity-relationship diagrams (ERD) to represent the databases, based on the...
Draw the Crow’s Foot database notation entity-relationship diagrams (ERD) to represent the databases, based on the three narratives below. Use Lucid Chart or another ERD diagramming tool to create your diagram. You do not need to create the databases, but to design it using applicable business rules according to your judgment. Submit a PDF of the Entity Relationship Diagram for each database. Remember to identify in your diagrams: All the main entities and the main attributes for each entity The...
Consumerization of Technology at IFG3 “There’s good news and bad news,” Josh Novak reported to the...
Consumerization of Technology at IFG3 “There’s good news and bad news,” Josh Novak reported to the assembled IT management team at their monthly status meeting. “The good news is that our social media traffic is up 3000% in the past two years. Our new interactive website, Facebook presence, and our U-Tube and couponing promotions have been highly successful in driving awareness of our ‘Nature’s Glow’ brand and are very popular with our target demographic—the under-30s. Unfortunately, the bad news is...
1. Vim commands: a. How do you auto indent your program? b. Explain what the following...
1. Vim commands: a. How do you auto indent your program? b. Explain what the following commands do: dd, y3, p, :set cindent (1 pt) VIM exercises These exercises on the computer need to be repeated by each student in the pair. This is to ensure that both students understand how to get around in Linux!!! For this part of the lab, you will create a .vimrc file that will help you develop your C++ programs using VIM. First, we...
3 SECURING THE WORKFORCE Diversity management in X-tech, a Japanese organisation This case is intended to...
3 SECURING THE WORKFORCE Diversity management in X-tech, a Japanese organisation This case is intended to be used as a basis for class discussion rather than as an illustration of the effective or ineffective handling of an administrative situation. The name of the company is disguised. INTRODUCTION In light of demographic concerns, in 2012, the Japanese government initiated an effort to change the work environment in order to secure the workforce of the future. Japan is world renowned for its...
2. SECURING THE WORKFORCE Diversity management in X-tech, a Japanese organisation This case is intended to...
2. SECURING THE WORKFORCE Diversity management in X-tech, a Japanese organisation This case is intended to be used as a basis for class discussion rather than as an illustration of the effective or ineffective handling of an administrative situation. The name of the company is disguised. INTRODUCTION In light of demographic concerns, in 2012, the Japanese government initiated an effort to change the work environment in order to secure the workforce of the future. Japan is world renowned for its...
What tools could AA leaders have used to increase their awareness of internal and external issues?...
What tools could AA leaders have used to increase their awareness of internal and external issues? ???ALASKA AIRLINES: NAVIGATING CHANGE In the autumn of 2007, Alaska Airlines executives adjourned at the end of a long and stressful day in the midst of a multi-day strategic planning session. Most headed outside to relax, unwind and enjoy a bonfire on the shore of Semiahmoo Spit, outside the meeting venue in Blaine, a seaport town in northwest Washington state. Meanwhile, several members of...
Please read the article and answear about questions. Determining the Value of the Business After you...
Please read the article and answear about questions. Determining the Value of the Business After you have completed a thorough and exacting investigation, you need to analyze all the infor- mation you have gathered. This is the time to consult with your business, financial, and legal advis- ers to arrive at an estimate of the value of the business. Outside advisers are impartial and are more likely to see the bad things about the business than are you. You should...
In February 2012, the Pepsi Next product was launched into the US market. This case study...
In February 2012, the Pepsi Next product was launched into the US market. This case study provides students with an interesting insight into PepsiCo’s new product process and some of the challenging decisions that they faced along the way. Pepsi Next Case Study Introduction Pepsi Next was launched by PepsiCo into the US market in February 2012, and has since been rolled out to various international markets (for instance, it was launched in Australia in September 2012). The new product...
Mattel Responds to Ethical Challenges Business Ethics This case was written by Debbie Thorne, John Fraedrich,...
Mattel Responds to Ethical Challenges Business Ethics This case was written by Debbie Thorne, John Fraedrich, O. C. Ferrell, and Jennifer Jackson, with the editorial assistance of Jennifer Sawayda. This case was developed for classroom discussion rather than to illustrate either effective or ineffective handling of an administrative, ethical, or legal discussion by management. All sources used for this case were obtained through publicly available material. Mattel, Inc. is a world leader in the design, manufacture, and marketing of family...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT