Database Management Systems

Concept: In SQL, aggregate functions such as:

• SUM()
• COUNT()
• AVG()
• MAX()
• MIN()

are used to perform calculations on a set of rows and return a single result.

To filter results based on aggregate values, SQL uses the HAVING clause.

Step 1: Understand the WHERE clause.
The WHERE clause filters rows before grouping takes place.

Example:

SELECT * FROM Employees WHERE Salary > 50000;

It cannot be used with aggregate functions directly.

Step 2: Understand the HAVING clause.
The HAVING clause is used to filter results after aggregation.

Example:

SELECT Department, COUNT(*)
FROM Employees
GROUP BY Department
HAVING COUNT(*) > 5;

This query returns only those departments having more than 5 employees.

Step 3: Conclusion.
Since filtering conditions applied to aggregate functions are handled using the HAVING clause, the correct answer is:

HAVING