Test Series

Question

Let A and B be two entities in an E-R diagram with simple single-valued attributes. R1 and R2 are two relationships between A and B, where R1 is one to many and R2 is many to many. R1 has 2 attributes and R2 has 3 attributes. What is the minimum number of tables required to represent this situation in the relational model?

Comments

I think 3 is enough...?

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3..?

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HOWWWW?

3 is correct.

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1 for A,1 for B and 1 for R2 (many to many relationship)

Answer 1

Total 3 tables will be required.

 

1 Relation will be required for representing A. 1 will be required for B. Now since R1 is a one-to-many relationship, its attributes can be shifted to the many side(i.e. entity having total participation in this relationship).

And for many-to-many, always remember that we need another relation to represent it. This relation will consist of (primary key of A, primary key of B, attributes of R2).