If order number serves as the primary key in the order relation and also appears as a nonkey attribute in the invoice relation, then order number is said to be a:
A) foreign key.
B) candidate key.
C) pointer.
D) relationship key.
E) marker.

Question

Quizplus · Accepted Answer

When a primary key from one relation appears as a nonkey attribute in another relation, it is referred to as a foreign key. In this case, the order number is the primary key in the order relation and appears as a nonkey attribute in the invoice relation, making it a foreign key.

If Order Number Serves as the Primary Key in the Order