The basic syntax of the HAVING clause is:
SELECT column1, aggregate_function(column2)
FROM table_name
GROUP BY column1
HAVING condition;
condition: A condition applied to the groups created by the GROUP BY clause.aggregate_function(column2): An aggregate function like SUM(), COUNT(), or AVG().Let’s say we want to find departments where the total salary exceeds $50,000. First, we group the employees by department and then use the HAVING clause to filter the results:
SELECT department, SUM(salary) AS total_salary
FROM employees
GROUP BY department
HAVING SUM(salary) > 50000;
In this example:
department column.SUM() function.HAVING clause filters out departments where the total salary is less than or equal to $50,000.WHERE filters rows before grouping, while HAVING filters after the data is grouped.WHERE for non-aggregated conditions and HAVING for conditions on aggregated data.The HAVING clause is a powerful tool for filtering aggregated data in MySQL. By applying it after grouping with GROUP BY, you can refine your results based on the aggregated values. Understanding how and when to use HAVING alongside GROUP BY helps in advanced data analysis and reporting.