Database - The Relational Model and Normalization - Discussion
Discussion Forum : The Relational Model and Normalization - General Questions (Q.No. 1)
1.
Every time attribute A appears, it is matched with the same value of attribute B, but not the same value of attribute C. Therefore, it is true that:
Discussion:
23 comments Page 3 of 3.
Shahin said:
9 years ago
@Emil.
If A -> B holds then it's not necessary the B -> A also hold true.
A B
----------------------------
b 5
b 5
c 5
For every occurrence of b in A there is value 5 in B hence A -> B.
But for every Value of B which is 5 is not same value in A (b,c two values in A).
Hence If A -> B holds then it's not necessary that B -> A also holds true.
If A -> B holds then it's not necessary the B -> A also hold true.
A B
----------------------------
b 5
b 5
c 5
For every occurrence of b in A there is value 5 in B hence A -> B.
But for every Value of B which is 5 is not same value in A (b,c two values in A).
Hence If A -> B holds then it's not necessary that B -> A also holds true.
(2)
Elias joseph said:
8 years ago
Answer is A because in a change of a implies that also b change.
Harsha said:
6 years ago
Because A is functional to B is less than or greater than to it.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers