Access Cumulative Total by Date

问题

I need to show the cumulative power of all our energy projects by their online date.

So, if a project came online in 2016, it was also online in 2017 and 2018 and should be counted in those totals. I basically need a table that answers the questions

      "What was our energy capacity as of 12/31/2016, 12/31/2017,etc"

I can do it by running a simple query over and over with different dates, but ideally I would run just one query and get the table I need.

I don't actually know how to code in SQL, so I just use the Access query designer, which might be making things more difficult.

Simple Query that gets what I want:

SELECT Sum(Projects.[System Size AC]) AS [SumOfSystem Size AC]
FROM Projects
WHERE (((Projects.[Online Date])<#1/1/2018#));

Query that gets an error:

SELECT DSum([Projects]![System Size AC],[Projects],Year([Online Date])<=[Yr]) AS [Run Sum], Year([Online Date]) AS Yr
FROM Projects
GROUP BY Year([Online Date]);

I can do it by running the simple query over and over with different dates, but ideally I would get one table with all the years in the online date column with like a cumulative total of all available project capacity available during that year

回答1:

You can do this using a correlated subquery:

SELECT Year(p.[Online Date]) as yr,
       SUM(p.[System Size AC]) as this_year,
       (SELECT SUM(p2.[System Size AC])
        FROM Projects as p2
        WHERE YEAR(p2.[Online Date]) <= YEAR(p.[Online Date])
       ) as running_sum
FROM Projects as p
GROUP BY Year([Online Date]);

来源：https://stackoverflow.com/questions/57042245/access-cumulative-total-by-date

标签

sql

ms-access