SQL SUM() Function

The SUM() function returns the total sum of a numeric column.

Example

Return the sum of all Quantity fields in the OrderDetails table:

SELECT SUM(Quantity)  
FROM OrderDetails;

Syntax

SELECT SUM(_column_name_) FROM _table_name_ WHERE _condition_;

Demo Database

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

OrderDetailID	OrderID	ProductID	Quantity
1	10248	11	12
2	10248	42	10
3	10248	72	5
4	10249	14	9
5	10249	51	40

Add a WHERE Clause

You can add a WHERE clause to specify conditions:

Example

Return the sum of the Quantity field for the product with ProductID 11:

SELECT SUM(Quantity)  
FROM OrderDetails  
WHERE ProductId = 11;

Use an Alias

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

Example

Name the column "total":

SELECT SUM(Quantity) AS total  
FROM OrderDetails;

Use SUM() with GROUP BY

Here we use the SUM() function and the GROUP BY clause, to return the Quantity for each OrderID in the OrderDetails table:

Example

SELECT OrderID, SUM(Quantity) AS \[Total Quantity\]  
FROM OrderDetails  
GROUP BY OrderID;

SUM() With an Expression

The parameter inside the SUM() function can also be an expression.

If we assume that each product in the OrderDetails column costs 10 dollars, we can find the total earnings in dollars by multiply each quantity with 10:

Example

Use an expression inside the SUM() function:

SELECT SUM(Quantity \* 10)  
FROM OrderDetails;

We can also join the OrderDetails table to the Products table to find the actual amount, instead of assuming it is 10 dollars:

Example

Join OrderDetails with Products, and use SUM() to find the total amount:

SELECT SUM(Price \* Quantity)  
FROM OrderDetails  
LEFT JOIN Products ON OrderDetails.ProductID = Products.ProductID;