SELECT SUM

It is also known as SQL SUM() function. It is used in a SQL query to return summed value of an expression.

Let’s see the Syntax for the select sum function:

 SELECT SUM (expression)  

FROM tables  

WHERE conditions; 

expression may be numeric field or formula.

This would produce the following result.

ID	EMPLOYEE_NAME	SALARY
1	JACK REACHER	32000
2	PADMA MAHESHWARI	22000
3	JOE PETRA	41000
4	AMBUJ AGRAWAL	21000

After using this SQL SELECT SUM example, it will produce the result containing the sum of the salary greater than 20000.

Total salary: 116,000

SQL SUM EXAMPLE with single field:

If you want to know how the combined total salary of all employee whose salary is above 20000 per month.

SELECT SUM (salary) AS "Total Salary"  

FROM employees  

WHERE salary > 20000;

In this example, you will find the expression as “Total Salary” when the result set is returned.

SQL SUM EXAMPLE with SQL DISTINCT:

You can also use SQL DISTINCT clause with SQL SUM function.

SELECT SUM (DISTINCT salary) AS "Total Salary"  

FROM employees  

WHERE salary > 20000;

SQL SUM EXAMPLE with SQL GROUP BY:

Sometimes there is a need to use the SQL GROUP BY statement with the SQL SUM function.

For example, we could also use the SQL SUM function to return the name of department and the total sales related to department.

SELECT department, SUM (sales) AS "Total Sales"  

FROM order_details  

GROUP BY department;

Let us take a table named order_details

ID	DEPARTMENT	DATE	DAILY SALES
1	Mechanical	2012-08-13	360
2	Electrical	2012-08-13	100
2	Electrical	2012-08-14	110
3	Electronics	2012-08-13	150
3	Electronics	2012-08-14	170

After using the SQL GROUP BY statement with SUM, you will find the following result.

DEPARTMENT	SUM(DAILY SALES)
Mechanical	360
Electrical	210
electronics	320