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The SQL AVG() Function

The AVG() function returns the average value of a numeric column.

The AVG() function ignores NULL values in the column.

Example

  SELECT AVG(Price)
FROM Products;

Note

NULL values are ignored.

SELECT AVG( column_name ) FROM table_name WHERE condition ;

Below is a selection from the Products table used in the examples:

ProductID	ProductName	SupplierID	CategoryID	Unit	Price
1	Chais	1	1	10 boxes x 20 bags	18.00
2	Chang	1	1	24 - 12 oz bottles	19.00
3	Aniseed Syrup	1	2	12 - 550 ml bottles	10.00
4	Chef Anton's Cajun Seasoning	2	2	48 - 6 oz jars	22.00
5	Chef Anton's Gumbo Mix	2	2	36 boxes	21.35

You can add a WHERE clause to specify conditions:

Example

  SELECT AVG(Price)
FROM Products
WHERE CategoryID = 1;

Give the AVG column a name by using the AS keyword.

Example

SELECT AVG(Price) AS [average price]
FROM Products;

To list all records with a higher price than average, we can use the AVG() function in a sub query:

Example

  SELECT * FROM Products
WHERE price >
  (SELECT AVG(price) FROM Products);

Here we use the AVG() function and the GROUP BY clause, to return the average price for EACH category in the "Products" table:

Example

  SELECT AVG(Price) AS AveragePrice, CategoryID
FROM Products
GROUP BY CategoryID;

You will learn more about the GROUP BY clause later in this tutorial.