Which one of the following is correct?
A. Each candidate key is a primary key
B. Each primary key is a foreign key
C. Each foreign key must refer a primary key of a relation.
D. Each foreign key refers a candidate key in a relation.
Answer:D
Which one of the following is correct?
A. Each candidate key is a primary key B. Each primary key is a foreign key C. Each foreign key must refer a primary key of a relation. D. Each foreign key refers a candidate key in a relation.