I have a master table with many clients' transactions per date. What I would like is to have the sum of their transaction per date but for every day that goes by I want to have the total sum of the previous dates.
How could I do that?
Looks like you want a running sum per client. The only way I know of how this could be done is with a report. A report can give you a running sum over a field, but a form cannot. Your report would have to group detail records by client and the running sum would have to be applied over the group(s). Pretty sure you could not do that if you group by date or any other field. Maybe research "MS Access report running sum over group" and see if that applies or helps.