SQL AVG Function - Complete Beginner Tutorial

Using AVG with GROUP BY

AVG is often combined with the GROUP BY clause to calculate averages for each group of rows.

This is useful for finding averages per category, department, or any grouping.

• Syntax: SELECT group_column, AVG(numeric_column) FROM table_name GROUP BY group_column;
• Each group returns its own average value.

Handling NULL Values in AVG

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

This ensures that missing or undefined values do not affect the result.

• If all values are NULL, AVG returns NULL.
• You can use COALESCE to replace NULLs if needed before averaging.

Examples of Using AVG

Let's look at practical examples to understand how AVG works.