Which of the following is not true about a NULL attribute?
A)On insertion,entering the data for that field is optional.
B)It is an important property of an attribute.
C)It must have a default value specified.
D)A primary key can't be NULL.

Question

Quizplus · Accepted Answer

C) is not true because a NULL attribute does not require a default value to be specified. NULL is used to represent missing or unknown data, and it is perfectly acceptable for a column to allow NULLs without having a default value.

Which of the Following Is Not True About a NULL