David,

Actually, the "bug" was fixed just by changing OrderItem.unitPrice and InvoiceItem.amount to currency-precise. The truncation vs. rounding behavior differs from database to database, and postgresql truncates.

I'm of course for changing these fields to currency-precise. I was able to get OFBiz to work fine by changing all the named fields and then changing UtilFormatOut.formatCurrency (see http:// issues.apache.org/jira/browse/OFBIZ-490)

What kind of potential bug would OrderItem/InvoiceItem calculated item total fix? Are you thinking something like 999 * 0.4375 = 98.5625, so is that 98.56 or 98.57 kind of a thing?

On Nov 21, 2006, at 8:34 PM, David E Jones wrote:


On Nov 21, 2006, at 9:00 PM, Si Chen wrote:

David,

Yeah, I got quite a surprise when I created products with prices like 0.4375 and they ended up being 0.43 in orders and on the invoices!

This sounds like a bug, like something is truncating instead of rounding...

I'm not sure why OrderItem.unitPrice should be different the Product or SupplierProduct price? If someone wants to use a 3- or 4-digit price, wouldn't they want it to be the unit price on their orders?

There is a pretty big different between OrderItem and the Product and SupplierProduct entities. The ProductPrice records represent an offer from the company to a prospective customer. The OrderItem record represents an offer from a customer to the vendor and if accepted by the vendor becomes an agreement between the two. When such an agreement is made it is for various specific amounts. At this point some companies may still want to have a precise amount.

By the time we get to an invoice we really need to have a fixed amount that won't change by variations in the calculation, and I guess that would be nice on the order as well. This was the reason for having a 2 decimal place amount in these two places.

Also, InvoiceItem.amount is not the line item's total amount. It is equivalent to the unitPrice on OrderItem, so ... that's why I thought they should all be changed to currency-precise

Of course, for people who are using 2-decimal prices, none of this would change things.

Reviewing it again based on the need for more precise prices common in B2B situations where large quantities and very small prices do happen perhaps what we should do is something like:

1. increase the precision of these fields, but after an initial calculation they should be used for information purposes only

2. add a field to the OrderItem and InvoiceItem that represents the calculated item total. This helps the display code so it doesn't have to calculate it over and over, but more importantly we now have a number that represents what the customer and vendor agreed on for the specific quantity, which is what is really important. This would only change if the order/invoice changes. To simplify things, and I think make a more useful number, this should _not_ include adjustments. It should simply represent the total for the quantity and unit price.

Anyone else have any thoughts on this? Implementing this would require a bit of effort so we should certainly discuss it first.

-David


On Nov 21, 2006, at 7:53 PM, David E Jones wrote:


On Nov 21, 2006, at 8:09 PM, Si Chen wrote:

Hi all-

I noticed that while Product.price is currency-precise, certain fields which are related to it are only currency-amount, causing loss of precision when original prices have 3 or 4 decimal places of precision. Specifically, I think the following should all be changed to currency-precise:
SupplierProduct.lastPrice
OrderItem.unitPrice, unitListPrice, unitAverageCost, unitRecurringPrice
InvoiceItem.amount

Is there any reason why these shouldn't be currency-precise?

Most of these look fine, but I'm not sure about OrderItem.unitPrice, and I'm pretty uncomfortable with InvoiceItem.amount.

OrderItem.unitPrice may be arguable because some calculation may be done based on that, but the InvoiceItem.amount should be something that never results in any surprises...

-David

Best Regards,

Si
[EMAIL PROTECTED]




Best Regards,

Si
[EMAIL PROTECTED]



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