Trouble making a running sum in Access query - sql

Question

I'm stuck trying to get a running sum to work in an Access query.
I've been playing around with various Dsum expressions, but they all have resulted in errors.
Basically, I have two columns, one with a year, one with a count of parts for that year, and I would like the third to be a running sum of the part count over the years.
My SQL for the first two columns looks like this:
SELECT DatePart("yyyy",[EoL]) AS AYear, Count(EquipmentQuery.Equipment) AS EquipCount
FROM EquipmentQuery
GROUP BY DatePart("yyyy",[EoL])
ORDER BY DatePart("yyyy",[EoL]);
Any suggestions on how to get the third column to work as a running sum?
Thanks for the help!

Answer 1

If you create a report, there is a property to calculate a running sum.
If you prefer a query, you can use a subquery to calculate the running sum:
SELECT DatePart("yyyy",[EoL]) AS AYear
, Count(eq1.Equipment) AS EquipCount
, (
SELECT Count(eq2.Equipment)
FROM EquipmentQuery eq2
WHERE DatePart("yyyy",eq2.[EoL]) <= DatePart("yyyy",eq1.[EoL])
) AS RunningSuma
FROM EquipmentQuery AS eq1
GROUP BY
DatePart("yyyy",[EoL])
ORDER BY
DatePart("yyyy",[EoL]);

Answer 2

try the following code:
SELECT Year([EQ1].[EOL]) AS Yr,
Sum(IIf(Year([EQ2].[eol])=Year([EQ1].[eol]),1,0)) AS [current],
Sum(IIf(Year([EQ2].[eol])<=Year([EQ1].[eol]),1,0)) AS [cumulative]
FROM [equipmentquery] AS EQ1, [equipmentquery] AS [EQ2]
GROUP BY Year([EQ1].[EOL]);
ansd if you want running totals instead of counts:
SELECT Year([EQ1].[EOL]) AS Yr,
Sum(IIf(Year([EQ2].[eol])=Year([EQ1].[eol]),[EQ2].equipment,0)) AS [current],
Sum(IIf(Year([EQ2].[eol])<=Year([EQ1].[eol]),[EQ2].equipment,0)) AS [cumulative]
FROM [equipmentquery] AS EQ1, [equipmentquery] AS [EQ2]
GROUP BY Year([EQ1].[EOL]);