Oracle Database SQL — Question 127

Which statement is true about using functions in WHERE and HAVING?

Answer options

• A. Using aggregate functions in the WHERE clause requires a subquery.
• B. Using aggregate functions in the HAVING clause requires a subquery.
• C. Using single-row functions in the WHERE clause requires a subquery.
• D. Using single-row functions in the HAVING clause requires a subquery.

Correct answer: A

Explanation

The correct answer is A because aggregate functions cannot be directly used in the WHERE clause without a subquery, as the WHERE clause operates on individual rows before aggregation. Options B, C, and D are incorrect as aggregate functions can be used in HAVING without a subquery, and single-row functions can be used in both WHERE and HAVING without requiring a subquery.