When transforming an E-R diagram into normalized relations, the identifier of the entity type becomes:
A) the primary key of the corresponding relation.
B) the foreign key in the corresponding relation.
C) a nonkey attribute in the corresponding relation.
D) a secondary key in the corresponding relation.
E) a homonym in the corresponding relation.

Question

Quizplus · Accepted Answer

The identifier of an entity type becomes the primary key of the corresponding relation. This is because the primary key is a unique identifier for each row in the table. In the E-R diagram, the identifier of an entity type represents a unique instance of the entity type, so it makes sense for it to become the primary key in the resulting relation.

When Transforming an E-R Diagram into Normalized Relations, the Identifier