We’ve learned how to write queries to retrieve information from the database. Now, we are going to learn how to perform calculations using SQL.

Calculations performed on multiple rows of a table are called aggregates.

In this lesson, we have given you a table named fake_apps which is made up of fake mobile applications data.

Here is a quick preview of some important aggregates that we will cover in the next five exercises:

• COUNT(): count the number of rows
• SUM(): the sum of the values in a column
• MAX()/MIN(): the largest/smallest value
• AVG(): the average of the values in a column
• ROUND(): round the values in the column

Let’s get started!