Sum grand totals of a selection of invoices between two dates
I like to sum the grand totals of a selection of invoices between two dates. I can make the selection through a portal with this formulain the filter: Invoices2::date ≥ Invoices::gDateStart and Invoices2::date ≤ Invoices::gDateEnd
Invoices is a TO and Invoices2 is a self-join relationship of Invoices.
From the invoices that are filtered I would like to sum the grand totals. I seem not to be able to find the right formula, nor I'm able to find a similar thread on this forum. Any help or direction to a similar thread is appreciated! Thanks in advance.