SUM usage and examples

Overview

SUM adds numeric values across all selected rows or within each GROUP BY group. It ignores NULL, while a group containing only NULL values returns NULL. For monetary data, choose an exact numeric type with suitable precision.

Basic syntax

SELECT SUM(amount) AS total_amount FROM orders;

Examples

SUM example

Sum the amount column in orders and verify it equals the four sample amounts combined.

Sample table

Table：orders

orders
amount
1200
900
1500
700

Run result

result
total_amount
4300

Common issues

Does SUM ignore NULL?

Yes. SUM normally ignores NULL; if every input is NULL, the result may also be NULL.

Can SUM be used with GROUP BY?

Yes. It commonly totals amounts or quantities by customer, department, or date.

Should SUM be used to count rows?

COUNT(*) is the usual row-count function; SUM is for numeric columns or conditional expressions.

Keep reading

COUNT AVG GROUP BY HAVING MAX MIN COUNT DISTINCT GROUP_CONCAT

SUM