group by having

The GROUP BY clause is used in SQL to group rows based on a specified column or expression. The HAVING clause is used in conjunction with the GROUP BY clause to filter the results based on a condition.

For example, suppose we have a table called "sales" with columns "region", "product", and "sales_amount". We can use the GROUP BY clause to group the sales by region and product:

SELECT region, product, SUM(sales_amount)
FROM sales
GROUP BY region, product;

This query will return the total sales amount for each combination of region and product. We can use the HAVING clause to filter the results to only show regions with total sales amounts greater than a certain amount:

SELECT region, product, SUM(sales_amount)
FROM sales
GROUP BY region, product
HAVING SUM(sales_amount) > 10000;

This query will return only the regions and products with total sales amounts greater than 10,000.