SUM

Aggregate function.

The SUM() function calculates the sum of a set of values.

警告

NULL values are not counted.

Syntax

SUM(<expr>)

Arguments

Arguments	Description
<expr>	Any numerical expression

Return Type

A double if the input type is double, otherwise integer.

Example

Create a Table and Insert Sample Data

CREATE TABLE sales_data (
  id INT,
  product_id INT,
  quantity INT
);

INSERT INTO sales_data (id, product_id, quantity)
VALUES (1, 1, 10),
       (2, 2, 5),
       (3, 3, 8),
       (4, 4, 3),
       (5, 5, 15);

Query Demo: Calculate the Total Quantity of Products Sold

SELECT SUM(quantity) AS total_quantity_sold
FROM sales_data;

Result

| total_quantity_sold |
|---------------------|
|         41          |