Given the basic ER and relational models, which of the following is INCORRECT?

Correct choice (the incorrect statement): In a row of a relational table, an attribute can have more than one value

Why this is incorrect:

• The basic relational model (and First Normal Form) requires each attribute in a tuple to hold a single (atomic) value or NULL.

• The ER model does allow multivalued and composite attributes; when mapping an ER schema to relations you must convert multivalued attributes into separate relations or columns.

• Typical representation: if an entity has multiple phone numbers, create a separate relation such as Phone(student_id, phone_number) so each row stores one atomic phone_number value.

Takeaway: The statement claiming that a relational table attribute can hold more than one value contradicts the atomic-value requirement of the basic relational model, so that statement is incorrect.