SQL SUM() Function
The 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;
Try it Yourself »
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 number of orders made for the product with ProductID 11:
SELECT SUM(Quantity)
FROM OrderDetails
WHERE ProdictId = 11;
Try it Yourself »
Use an Alias
Give the summarized column a name by using the AS keyword.
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() parenthesis:
SELECT SUM(Quantity * 10)
FROM OrderDetails;
Try it Yourself »
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;
Try it Yourself »
You will learn more about Joins later in this tutorial.
