Question

For a binary one to one relationship, the ________ of the participating entity sets becomes the prime attribute

(a) Intersection of primary keys

(b) Primary key of either one

(c) Union of primary keys

(d) Primary key on the many side

I have been asked this question in class test.

I would like to ask this question from Reduction to Relational Schema in portion Database Design and the ER Model of RDBMS

Answer 1

Right choice is (b) Primary key of either one

Easiest explanation: For a binary one to one relationship, the primary key of either one of the participating entity sets becomes the prime attribute.