Extended price = Unit_Price X Quantity
Now you add a new discount amount.
( Unit_Price X Quantity ) -dDiscount_amount
In a straight calc every existing line item has been changed. But the old invoices did not get the discount. And you've just changed the amounts used for Invoice total and for taxes too.
If it is an "AEC - Do not Modify" then adding the discount doesn't change existing invoices.
For the sake of discussion let's use something really simple like Extended Price
UnitPrice x Qty
Would there be any benefit from setting this up instead as an Auto-enter calc using the "prohibit modfication" option.
Using your example, I don't think so. Consider, however, a case where the calculation's result needs to be validated as unique.
Thanks ch0c0halic and Michael!
Michael: I can understand that a field may have a uniqueness requirement.
I can't quite picture an AEC no-mod calc that might produce such a result.
Have you got an example?
Not sure where your difficulty lies. Suppose you want the combination of FirstName & LastName to be validated as unique. A calculation field =
FirstName & " " & LastName
cannot be validated. A text field, auto-entering the same formula, can.
Prohibit modification is intended for serial numbers that have to act as primary keys (always auto-generated, unique and not reusable).
Eg.: Customer_ID should be auto-entered and modification prohibited.
A good example would be an audit log field. This allows the field to be indexed , stops people from modifying the field contents and allows people to copy the contents of the field if required.
"Prohibit modification is intended for serial numbers..."
Well no; as we have seen in the discussion it is intended for/useful for other purposes besides that.
I should have add "amongst other uses" or "for example".
I Apologize for my dreadful English