Re: Newbie question

From: David Cressey <>
Date: Thu, 23 Jun 2005 10:36:27 GMT
Message-ID: <Lgwue.10487$>

"Paul" <> wrote in message news:42b9b3de$0$30831$

> True. But then many database constraints can be duplicated on the client
> to avoid repeated round-trips to the server. There was a long thread
> here a year or so ago on the desirability of clients being able to read
> the database constraints instead of being redundantly recoded. And then
> risking getting out of sync with each other.

There is value in avoiding round trips to the server.

With regard to keeping the client and the database in synch with regard to data constraints (database constraints?), there is another alternative. Allow both the client and the database to inherit the constraints from a common source. That's why Kenneth Downs' work is so interesting to me.

> True again, there is no guarantee someone won't type in another valid
> key, but it does knock out the vast majority of mistakes. I guess the
> most common error is to make a mistake in a single character (writing a
> 1 as a 7 for example). I think that checksums are specifically designed
> to ensure that changing any one character will invalidate the checksum.
> I could be wrong here but if not, they certainly would take care of most
> cases.

> And to check that the key is valid (i.e. in the database) and not just
> well-formed, you do need a trip to the server. But hopefully not many
> entries will manage to get to that stage.

Maybe "not many erroneous entries". Hopefully, the vast majority of entries will be correct, right? Received on Thu Jun 23 2005 - 12:36:27 CEST

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