Tomasz Ostrowski wrote:
On 2008-05-12 20:49, Justin wrote:
We take (List Price * discount Percent) * Number of Pieces = net
price.
This is wrong. You should do in Excel:
( price * amount ) * discount
As otherwise any small error in representation of price*discount would
be multiplied by usually high amount.
Your saying in Excel, Multiplication is not Commutativity??? that sends shudders down my back
I'd do this way to get it right:
round( round(price * amount, 2) * discount, 2)
This way every sum should match. There could be errors, but in pennies,
not dollars. These errors will be because Excel does not have a decimal
type.
That makes sense you are keeping the precision the same through the calculation
It is a lost case to break Postgres so it will match Excel. Much easier
would be to correct Excel spreadsheet. And this is a right thing to do.
Regards
Tometzky
