When changing the minimum cardinality on the parent side of the relationship from zero to one,the foreign key ________.
A)must be changed from NULL to NOT NULL
B)must be changed from NOT NULL to NULL
C)must be changed to a composite key
D)must be changed to a surrogate key

Question

Quizplus · Accepted Answer

When the minimum cardinality on the parent side of the relationship is changed from zero to one, it means that each child entity must be associated with a parent entity. Therefore, the foreign key on the child side must have a corresponding value in the parent table. To ensure this, the foreign key must be changed from NULL to NOT NULL.

When Changing the Minimum Cardinality on the Parent Side of the Relationship