Aggregation Intro

SQL lets you summarize and analyze large datasets using aggregate functions. These functions return a single value calculated from multiple rows of data.

You don’t use them to edit data — instead, they help you answer questions like:

• What's the total revenue?
• How many orders were placed?
• What's the average rating?

Aggregate functions are used in a SELECT statement to return a summary value.

You'll explore each aggregate function in more detail starting with COUNT() and SUM() in the next lesson.