SQL HAVING Function
Quick summary: The SQL HAVING clause filters aggregated results after GROUP BY.
SQL HAVING Syntax
SELECT column, aggregate_function(column) FROM table_name GROUP BY column HAVING aggregate_function(column) conditionSQL
SQL HAVING Basic examples
SELECT status, COUNT(*) FROM orders GROUP BY status HAVING COUNT(*) > 10;SQL
Output:
Statuses with more than 10 ordersFilters groups based on aggregate conditions.
SQL HAVING Real-world usage
SELECT user_id, SUM(total) AS revenue FROM orders GROUP BY user_id HAVING SUM(total) > 1000;SQL
Output:
High-value usersFinds users exceeding a revenue threshold.
SQL HAVING Edge cases
SELECT COUNT(*) FROM orders HAVING COUNT(*) > 0;SQL
Output:
1 rowHAVING can be used without GROUP BY in some databases.
SQL HAVING Common mistakes
Using WHERE instead of HAVING
WHERE cannot filter aggregated values.
Incorrect
WHERE COUNT(*) > 10Correct
HAVING COUNT(*) > 10Use HAVING for aggregate filters.
SQL HAVING Frequently Asked Questions
What does HAVING do in SQL?
Filters grouped results.
Difference between WHERE and HAVING?
WHERE filters rows, HAVING filters groups.
Use case of HAVING?
Filtering aggregates.
Syntax?
HAVING condition.
Common mistake?
Using HAVING instead of WHERE.
Used with GROUP BY?
Yes.
Supports aggregates?
Yes.
Performance?
Slower than WHERE.
Handles NULL?
Yes.
Used in reports?
Yes.
Alternative?
Subqueries.
Best practice?
Use WHERE before grouping.