HAVING Clause

The HAVING clause was added to SQL because the WHERE keyword cannot be used after aggregate functions to group the result-set.

SELECT column_name(s)
FROM table_name
WHERE condition
GROUP BY column_name(s)
HAVING condition
ORDER BY column_name(s);

Difference between ORDER BY, GROUP BY, and HAVING CLAUSE

Clause	Purpose	Aggregate Functions Allowed?	Execution Order	Example Use Case
WHERE	Filters individual rows before aggregation	❌ No	Before GROUP BY	Find employees with salary > 50,000
GROUP BY	Groups rows and applies aggregate functions	✅ Yes	After WHERE, before HAVING	Find the highest salary per department
HAVING	Filters aggregated results after GROUP BY	✅ Yes	After GROUP BY	Find departments where max salary > 80,000