SQL
SQL Aggregation with GROUP BY and HAVING
Master SQL aggregation: count, sum, average, min, max, and filter grouped results using GROUP BY and HAVING clauses for powerful data analysis.
SELECT category_id, COUNT(product_id) AS total_products, AVG(price) AS average_price
FROM products
GROUP BY category_id
HAVING COUNT(product_id) > 5
ORDER BY average_price DESC;
How it works: This query aggregates product data by category, counting total products and calculating the average price for each. The GROUP BY clause groups rows with the same category_id. The HAVING clause then filters these groups, showing only categories that contain more than 5 products, allowing for post-aggregation filtering.