Which of the following types of constraints will not allow NULL values?
A) UNIQUE
B) FOREIGN KEY
C) PRIMARY KEY
D) all of the above

Question

Which of the following types of constraints will not allow NULL values?​
A) ​UNIQUE
B) ​FOREIGN KEY
C) ​PRIMARY KEY
D) ​all of the above

Quizplus · Accepted Answer

The PRIMARY KEY constraint does not allow NULL values as it uniquely identifies each record in a table. UNIQUE and FOREIGN KEY constraints also ensure data integrity, but they do allow for NULL values in certain circumstances.

Which of the Following Types of Constraints Will Not Allow