2015. 6. 20. 17:38
http://www.w3schools.com/sql/sql_func_avg.asp
The AVG() Function
The AVG() function returns the average value of a numeric column.
SQL AVG() Syntax
SELECT AVG(column_name) FROM table_name
Demo Database
In this tutorial we will use the well-known Northwind sample database.
Below is a selection from the "Products" table:
ProductID | ProductName | SupplierID | CategoryID | Unit | Price |
---|---|---|---|---|---|
1 | Chais | 1 | 1 | 10 boxes x 20 bags | 18 |
2 | Chang | 1 | 1 | 24 - 12 oz bottles | 19 |
3 | Aniseed Syrup | 1 | 2 | 12 - 550 ml bottles | 10 |
4 | Chef Anton's Cajun Seasoning | 2 | 2 | 48 - 6 oz jars | 21.35 |
5 | Chef Anton's Gumbo Mix | 2 | 2 | 36 boxes | 25 |
SQL AVG() Example
The following SQL statement gets the average value of the "Price" column from the "Products" table:
The following SQL statement selects the "ProductName" and "Price" records that have an above average price:
Example
SELECT ProductName, Price FROM Products
WHERE Price > (SELECT AVG(Price) FROM Products);
WHERE Price > (SELECT AVG(Price) FROM Products);
Try it yourself »
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