When do you use HAVING clause in an SQL query code example

Example 1: sql count having

SELECT COUNT( * ) 
FROM agents 
HAVING COUNT(*)>1; --count is greater than 1

Example 2: having in mysql

SELECT 
    ordernumber,
    SUM(quantityOrdered) AS itemsCount,
    SUM(priceeach*quantityOrdered) AS total
FROM
    orderdetails
GROUP BY 
   ordernumber
HAVING 
   total > 1000;