SQL - Calculate Running Total

SQL > Advanced SQL > Running Totals

Displaying running totals is a common request, and there is no straightforward way to do so in SQL. The idea for using SQL to display running totals similar to that for displaying rank: first do a self-join, then, list out the results in order. Where as finding the rank requires doing a count on the number of records that's listed ahead of (and including) the record of interest, finding the running total requires summing the values for the records that's listed ahead of (and including) the record of interest.

Let's use an example to illustrate. Say we have the following table,

Table Total_Sales

Name	Sales
John	10
Jennifer	15
Stella	20
Sophia	40
Greg	50
Jeff	20

we would type,

SELECT a1.Name, a1.Sales, SUM(a2.Sales) Running_Total
FROM Total_Sales a1, Total_Sales a2
WHERE a1.Sales <= a2.sales or (a1.Sales=a2.Sales and a1.Name = a2.Name)
GROUP BY a1.Name, a1.Sales
ORDER BY a1.Sales DESC, a1.Name DESC;

Result:

Name	Sales	Running_Total
Greg	50	50
Sophia	40	90
Stella	20	110
Jeff	20	130
Jennifer	15	145
John	10	155

The combination of the WHERE clause and the ORDER BY clause ensure that the proper running totals are tabulated when there are duplicate values.

List of SQL Complex Operations

Operation	Description
Rank	Calculates the ranking of a series of numbers
Median	Calculates the median of a series of numbers
Running Totals	Calculates the running total for a series of numbers
Percent To Total	Calculates the percent to total for each number in a series
Cumulative Percent To Total	Calculates the cumulative percent to total for each number in a series

Next: SQL Percent To Total

SQL Running Total

List of SQL Complex Operations