If it is possible for a subquery to return a NULL value to the outer query for comparison,the ____ function should be used to substitute an actual value for the NULL.
A) IS NULL
B) NVL
C) !NVL
D) NVLS

Question

​If it is possible for a subquery to return a NULL value to the outer query for comparison,the ____ function should be used to substitute an actual value for the NULL.
A) ​IS NULL
B) ​NVL
C) ​!NVL
D) ​NVLS

Quizplus · Accepted Answer

The NVL function can be used to substitute an actual value for a NULL value returned by a subquery. The IS NULL function is used to determine if a value is NULL, not to substitute a value for NULL. The other answer choices, !NVL and NVLS, are not valid Oracle functions.

​If It Is Possible for a Subquery to Return a NULL

If It Is Possible for a Subquery to Return a NULL