Introduction to SQL HAVING Clause

Having clause is used with SQL Queries to give more precise condition for a statement. It is used to mention condition in Group by based SQL queries, just like WHERE clause is used with SELECT query.

Syntax for HAVING clause is,

SELECT column_name, function(column_name)
FROM table_name
WHERE column_name condition
GROUP BY column_name
HAVING function(column_name) condition

Example of SQL Statement using HAVING

Consider the following Sale table.

Suppose we want to find the customer whose previous_balance sum is more than 3000.

We will use the below SQL query,

SELECT *
FROM sale GROUP BY customer
HAVING sum(previous_balance) > 3000

Result will be,

The main objective of the above SQL query was to find out the name of the customer who has had a previous_balance more than 3000, based on all the previous sales made to the customer, hence we get the first row in the table for customer Alex.