Counting Rows with COUNT

COUNT is an aggregate function that counts rows. It's one of the most commonly used functions in SQL.

COUNT Syntax

-- Count all rows
SELECT COUNT(*) FROM table_name;

-- Count non-NULL values in a column
SELECT COUNT(column_name) FROM table_name;

New Tables Available

Starting from this lesson, you have access to more tables:

• users - User accounts
• categories - Product categories
• products - Products with prices and stock

Explore the schema panel on the left to see all columns!

Exercises

COUNT(*) vs COUNT(column)

• COUNT(*) counts all rows, including those with NULL values
• COUNT(column) counts only non-NULL values in that column

Free Practice

Try:

• Count products in different categories
• Count products within a price range
• Count products with stock below a threshold