[forwarded submission from a non-member address -- rjk]
From: Dave Turner <[EMAIL PROTECTED]>
Date: 27 Mar 2002 19:59:21 -0500
Subject: Re: [Boston.pm] DBI weirdness
To: Matthew Brooks <[EMAIL PROTECTED]>
Cc: Joel Gwynn <[EMAIL PROTECTED]>, [EMAIL PROTECTED]
This is a non-answer to the question. It could well be that in his
particular case, this doesn't matter. Or, maybe it's too expensive. And
checking for existence before doing a delete is totally pointless, as
delete returns the number of rows deleted, and a delete which operates
on no records is (excluding bizarre triggers) a no-op.
Crashing is not acceptable in the presense of perfectly fine SQL.
Anyway, the update statement says something more like "wash each of my
cars", which is a no-op in the case of no cars.
On Wed, 2002-03-27 at 18:29, Matthew Brooks wrote:
>
> MessageChecking for the existence of a particular record in a database
> before performing an UPDATE/DELETE on it is just good programming
> practice. An UPDATE/DELETE by definition, and in comparison to an INSERT,
> assumes that the record already exists.
>
> Think of it this way... If someone asked you to take their car over to
> the car wash for them, but they didn't actually own a car; how likely is
> it that you would be able to get their car washed?
>
> Matthew
>
>
> ----- Original Message -----
> From: Joel Gwynn
> To: [EMAIL PROTECTED]
> Sent: Wednesday, March 27, 2002 12:27 PM
> Subject: [Boston.pm] DBI weirdness
>
>
> This is something bothersome that just started happening, or I just
> began noticing. If I try to update or delete a record, like so:
> "update addresses set first_name='Joel' where user_id=1", and there is
> no record matching user_id=1, my script hangs. If the record exists,
> everything is fine.
>
> I've been working around this by checking for the existence of a record
> before deletion/updating, but it doesn't seem right that I should need
> to do this. What could be the problem?
>
> I'm using DBI 1.14 on WindowsNT with SQL Server.
--
-Dave Turner Stalk Me: 617 441 0668
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