Subject Re: [ib-support] Unique key that accepts null
Author Helen Borrie
At 06:53 PM 10-08-01 +0800, you wrote:
>Thanks Helen,
> >Yes; and sometimes barcodes get duplicated (by the manufacturers, in
>error) so a UNIQUE constraint can cause problems even where all items have a
>barcode. Generally I would want to log such cases and flag the row for a
>Do you mean that you would just leave it there and flag it with some sort of
>error code? Why?

Because, in practice, if you have two items having the same barcode, there is a 50% or better chance that a price lookup will return the price for the wrong item. You can't trust external systems!

So I'd have a flag on the record that the system could respond to by sending a message warning the user to check that it is the right item and, if necessary, do a manual lookup, offer all duplicates for selection or whatever.

That's all. It's not an InterBase issue but a matter of the pragmatics of development. <g>


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