MS Access - Sub Query with Running Total using DSUM with filter

Question

In order to generate running total of Sales Qty in MS Access, I used below query, it is working as expected

SELECT ID, [Product Line], DSUM(\"[Qty]\",\"[SalesDat         


        

Answer 1

Rather than using domain aggregate functions (such as DSum) which are known to be notoriously slow, I would suggest using a correlated subquery, such as the following:

select q.* from
(
    select t.id, t.[product line], t.qty, 
        (
            select sum(u.qty) 
            from salesdata u 
            where u.[product line] = t.[product line] and u.id <= t.id
        ) as runningtotal
    from salesdata t
    where t.[product line] like "*Electronics*"
) q
where q.runningtotal < 100

EDIT:

select t.*, q.runningtotal from salesdata t inner join
(
    select t.id, 
        (
            select sum(u.qty) 
            from salesdata u 
            where u.[product line] like "*Electronics*" and u.id <= t.id
        ) as runningtotal
    from salesdata t
) q on t.id = q.id
where q.runningtotal < 100 and t.[product line] like "*Electronics*"