SQL: What is an aggregate function?

In a nutshell

An aggregate function performs a calculation on multiple values and returns a single value.

For example, assuming you have the following salaries table:

You can calculate the sum of all salaries.salary values for all records with:

select sum(salary) from salaries;

Examples of aggregate functions

• COUNT()
• SUM()
• AVG()
• MAX()
• MIN()

Sources

• MySQL SUM – mysqltutorial.com