RE: Embedded SQL update a field based on difference of totals in2otherfiles

It doesn't work.

2 problems that I see right off:

1) On vendors with at least 1 open invoice and no unmatched payments,
nothing is done to the AMDUE field.

2) Only 1 vendor actually has an unmatched payment.  This vendor has 2 open
invoices.  The AMDUE field has been set to (the sum of the 2 invoices) less
(The unmatched payment amount * 2).  Ie, each open invoice is $3.75, for a
total of $7.50.  The unmatched payment amount is $3.00.  AMDUE s/b set to
$4.50, but was actually set to $1.50.  The payment amount was subtracted
twice, probably related to the fact there are _2_ open invoices.  To confirm
this, I slammed in a 3rd invoice, and then the payment amount was subtracted
3 times.

I may have to give up and use record I/O.  I think I've already spent too
much time starting last week, but this seems like such a proper fit for SQL.