suppose i want to edit sale #1.
if i choose onetomany plugin, in the left pane i'll see all the rows from LINES_OF_SALE, which is exactly what i don't want. why should i see the lines of sales of sales #2 and #3. there's another issue: onetomany plugin (as far as i'm concerned) does not allow the user to edit the data.
the custom solution to this issue is to have a subform (sometimes called subfile). when the user adds or edits a sale, you can also add, edit or delete a line of sale (but only those that belongs to the sale).
taking in account that i have a deadline next week, i was wondering if i can find another solution (for example, to put a link in the sale's form to the corresponding lines of sale).