how can i get excel pivot tables to have a row with zero counts?
 

what i'm trying to do is kind of like an sql outer join.
if i have a table of product, month, sales, where if there are zero sales
for that product for that month, there are no sales; if i do a pivot table,
then that has no line for that month/product, and when i do a pivot chart,
there is no point for that month for that product, which screws up the chart.
i'd like a line with count of zero to appear in the pivot table so that the
month appears on the chart with zero.