SQL • LESSON 09

COUNT, SUM, AVG

Learn how SQL aggregate functions summarize data across rows.

🟡 Intermediate⏱ 2 Minutes⭐ 170 XP

🤔 THE QUESTION

How can we calculate the total number of employees?

💡 WHAT IS IT?

COUNT() is an aggregate function that counts rows or non-null values in a result.

🎯 WHAT IS IT USED FOR?

It is useful for measuring record counts, monitoring data volume, creating reports, and answering questions such as 'How many records do we have?'

💻 EXAMPLE

SELECT COUNT(*) AS employee_count
FROM employees;

Practice using COUNT, SUM, and AVG to calculate useful statistics from employee data.