Register

ISRO2015-16

• edited by
5,701 views
8 votes
8 votes

Consider the following Relationship Entity Diagram(ERP)

Which of the following possible relations will not hold if the above ERD is mapped into a relation model?

  1. Person (NID, Name)
  2. Qualification (NID, ExamID, QualifiedDate)
  3. Exam (ExamID, NID, ExamName)
  4. Exam (ExamID, ExamName)
• edited by
User Avatar

3 Answers

Best answer
15 votes
15 votes

If we have to convert an ER -Diagram into Relational model then 

we can create one table for each entity .In this way we are going to get one table for Entity Person and one table for Entity Exam.we can't avoid these 2 Tables .

Now problem is with relationship Entity on which side should we add it unfortunately we can't add it on either side so we have to create a new table in which we are going to take Primary key of Entity Person and Primary key of Entity Exam .So in this way we can represents the relationship .

So option A ,B and D seems okay but Option C does not make any sense .Why do we need this if we have already represented all our Entity . 

• selected by
User Avatar
2 votes
2 votes
Correct answer is C. As exam is strong entity by itself, it doesn’t requires any primary key of any other attribute.
User Avatar
Voting & Accepting an answer helps improve the community
Answer:
← PreviousNext →
← Previous in categoryNext in category →

Related questions

7 votes
7 votes
3 answers
1
go_editor asked Jun 19, 2016
3,816 views
ISRO2015-39
If a node has $K$ children in $B$ tree, then the node contains exactly _____ keys. $K^2$ $K-1$ $K+1$ $\sqrt{K}$
If a node has $K$ children in $B$ tree, then the node contains exactly _____ keys.$K^2$$K-1$$K+1$$\sqrt{K}$
User Avatar
8 votes
8 votes
2 answers
4
go_editor asked Jun 17, 2016
3,900 views
ISRO2015-20
Let $\text{R = (A, B, C, D, E, F)}$ be a relation scheme with the following dependencies $\text{C} \rightarrow \text{F, E} \rightarrow \text{A}, \text{EC} \rightarrow \text{D, A} \rightarrow \text{B}$. Which of the following is a key of $\text{R}?$ $\text{CD}$ $\text{EC}$ $\text{AE}$ $\text{AC}$
Let $\text{R = (A, B, C, D, E, F)}$ be a relation scheme with the following dependencies $\text{C} \rightarrow \text{F, E} \rightarrow \text{A}, \text{EC} \rightarrow \te...
User Avatar
Link Copied!