Which of the following statements about a PRIMARY KEY is incorrect?
A) It identifies which column(s)uniquely identify each record.
B) It can be NULL,as long as the FOREIGN KEY contains a value.
C) Each data value must be unique.
D) none of the above

Question

Which of the following statements about a PRIMARY KEY is incorrect?​
A) ​It identifies which column(s)uniquely identify each record.
B) ​It can be NULL,as long as the FOREIGN KEY contains a value.
C) ​Each data value must be unique.
D) ​none of the above

Quizplus · Accepted Answer

A primary key cannot be NULL, as its purpose is to uniquely identify each record in the table. The foreign key may contain a NULL value, but not the primary key.

Which of the Following Statements About a PRIMARY KEY Is