Aggregate Functions

Introduction

SQL is very often used for gathering and expressing the data in a summary form. This process is known as data aggregation and is conducted with the help of several aggregate functions. In short, an SQL aggregate function outputs a single value by computing some calculations on a given set of input values. These functions perform the operations over entire columns and, in most cases, ignore null values (not applicable only for the COUNT() function). Since these functions are used all the time in SQL, it’s extremely important and beneficial to become as familiar with them as possible. In this tutorial, we will go over five aggregate functions: AVG(), COUNT(), MIN(), MAX(), and SUM().