Beginner

61. COUNT Function

Learn how to count rows or non-null values using the COUNT function.

📘 Lesson 61 of 728 ⏱ 7 min 🎯 Beginner

The COUNT function returns the number of rows or non-null values that match a query. COUNT(*) counts rows, while COUNT(column_name) counts non-null values in the specified column.

Counting records is one of the most common analytical tasks. Analysts use COUNT to measure customers, employees, transactions, orders, products, and other business records.

A manager wants to know how many employees are currently stored in the Employees table. COUNT(*) can return the total number of employee records.

SQL 
SELECT
    COUNT(*) AS TotalEmployees
FROM Employees;

COUNT is widely used in customer analysis, transaction reporting, sales analysis, employee reporting, operational dashboards, and business metrics.

  • COUNT is an aggregate function.
  • COUNT(*) counts rows.
  • COUNT(column_name) ignores NULL values.
  • COUNT can be combined with GROUP BY.
  • COUNT is commonly used in business reporting.
What does COUNT(*) return?

COUNT(*) returns the number of rows in the result set.

What is the difference between COUNT(*) and COUNT(column)?

COUNT(*) counts rows, while COUNT(column) counts only non-null values in that column.

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