SUM returns the total value in a column of all selected records or all the DISTINCT (unique) values selected by the query. : SUM « Aggregate Functions « SQL Server / T-SQL Tutorial

1. SQL Server / T-SQL Tutorial
2. Aggregate Functions
3. SUM

This function is used for only number datatypes.
All NULL values are ignored.

5>
6>
7> CREATE TABLE sales(
8>    stor_id        char(4)           NOT NULL,
9>    ord_num        varchar(20)       NOT NULL,
10>    ord_date       datetime          NOT NULL,
11>    qty            smallint          NOT NULL,
12>    payterms       varchar(12)       NOT NULL,
13>    title_id       varchar(80)
14> )
15> GO
1> insert sales values('1', 'QA7442.3', '09/13/94', 75, 'ON Billing','1')
2> insert sales values('2', 'D4482',    '09/14/94', 10, 'Net 60',    '1')
3> insert sales values('3', 'N914008',  '09/14/94', 20, 'Net 30',    '2')
4> insert sales values('4', 'N914014',  '09/14/94', 25, 'Net 30',    '3')
5> insert sales values('5', '423LL922', '09/14/94', 15, 'ON Billing','3')
6> insert sales values('6', '423LL930', '09/14/94', 10, 'ON Billing','2')
7> GO

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)
1>
2>
3> select SUM(qty) from sales;
4> GO

-----------
        155

(1 rows affected)
1>
2> drop table sales;
3>
4> GO