SQLDailyDrills

HAVING

Filter groups after they are aggregated. WHERE filters rows before.

Syntax

SELECT … GROUP BY column HAVING condition_on_an_aggregate;

Example

SELECT customer_id, COUNT(*) AS orders FROM orders WHERE customer_id IS NOT NULL GROUP BY customer_id HAVING COUNT(*) >= 2;

Customers who placed at least two orders.

Tables used: orders. Try it in a lesson below.

Common mistakes

  • Put conditions on plain columns in WHERE, which is faster. Use HAVING only for conditions on aggregates.

Practise it