MySQL AVG Function - Complete Tutorial

Understanding the AVG Function

The AVG function calculates the mean value of a numeric column across rows in a query result.

It ignores NULL values, so only rows with actual numeric data are considered in the calculation.

• Syntax: AVG(column_name)
• Returns a floating-point number representing the average.
• Works only on numeric data types.

Using AVG in Basic Queries

You can use AVG to calculate the average of a column for the entire table.

For example, to find the average price of products in a products table:

Using AVG with GROUP BY

AVG is often combined with GROUP BY to calculate averages per category or group.

For example, to find the average salary per department in an employees table:

Handling NULL Values in AVG

The AVG function automatically ignores NULL values in the column when calculating the average.

This behavior ensures that missing or undefined values do not skew the average.

• If all values are NULL, AVG returns NULL.
• You do not need to filter out NULLs manually before using AVG.

Combining AVG with Other Aggregate Functions

AVG can be used alongside other aggregate functions like COUNT, SUM, MIN, and MAX for comprehensive data analysis.

For example, to get the average, minimum, and maximum prices of products: