Cumulative Sum

Ways to get a Cumulative Sum:

Initial setup:
Creating the table and populating the table.
CREATE TABLE #Sales (DayCount smallint, Sales money, RunningTotal money)


INSERT INTO #Sales (DayCount, Sales, RunningTotal)
SELECT 1, 10, 0
union all
SELECT 2, 7, 0
union all
SELECT 3, 2, 0
union all
SELECT 4, 6, 0

GO

SELECT * FROM #Sales ORDER BY DayCount

GO




Method 1:
DECLARE @RunningTotal money
SET @RunningTotal = 0

UPDATE #Sales
SET @RunningTotal = RunningTotal = @RunningTotal + Sales

GO

SELECT * FROM #Sales ORDER BY DayCount

GO



Method 2:

SELECT
a.DayCount
, a.Sales
, SUM(b.Sales) AS 'Running Total'
FROM
#Sales a
JOIN #Sales b ON b.DayCount <= a.DayCount GROUP BY a.DayCount , a.Sales ORDER BY a.DayCount , a.Sales