SQL HAVING Keyword

The HAVING clause in SQL is used to filter the results of a GROUP BY query. It's similar to the WHERE clause, but it operates *after* the grouping has taken place.

HAVING: Definition and Usage

You use HAVING to specify conditions based on aggregate functions (like COUNT(), SUM(), AVG(), MAX(), MIN()). WHERE can't be used directly with aggregate functions because it filters *before* grouping occurs; HAVING filters *after* grouping.

Syntax

SELECT aggregate_function(column_name), ...
FROM table_name
WHERE condition
GROUP BY column_name
HAVING condition;
      

Examples

Filtering Groups

This query counts customers per country and only includes countries with more than 5 customers.

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5;
      

COUNT(CustomerID) | Country
--------------------------
7                 | USA       (Example output; adapt to your data)
      

Filtering and Sorting Groups

This query does the same as above but also sorts the results in descending order based on the customer count.

SELECT COUNT(CustomerID), Country
FROM Customers
GROUP BY Country
HAVING COUNT(CustomerID) > 5
ORDER BY COUNT(CustomerID) DESC;
      

COUNT(CustomerID) | Country
--------------------------
7                 | USA       (Example output; adapt to your data)