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From:Tim Bunce Date:June 2 1999 10:04am
Subject:Re: Drivers giving different results
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On Mon, May 31, 1999 at 12:25:49PM +0200, Michael Widenius wrote:
> 
> Hi!
> 
> You can currently get the above behaviour if you add the flag
> CLIENT_FOUND_ROWS to the last argument of mysql_real_connect().
> 
> One problem is that ANY SQL server is allowed to optimize the query:
> 
>	UPDATE foo SET col=col
> to
>	UPDATE foo SET col=col WHERE col<>col
> 
> I think that one should strongly discourage the use of affected rows in the
> above manner as any SQL server may add the above optimisation in any
> updated version!

What makes you say that? Specifically. Is it specified somewhere in
a standards document somewhere? (The word "affected" is, sadly, rather
too ambiguous to be relied upon by itself.)

I know of no other SQL server that does that. Do you?

Tim.
Thread
Re: Drivers giving different resultsJochen Wiedmann25 May
  • Re: Drivers giving different resultsVivek Khera25 May
  • Re: Drivers giving different resultsTim Bunce26 May
  • Re: Drivers giving different resultsDan Busarow29 May
    • Re: Drivers giving different resultsJochen Wiedmann29 May
  • Re: Drivers giving different resultsMichael Widenius2 Jun
    • Re: Drivers giving different resultsTim Bunce2 Jun
      • Re: Drivers giving different resultsMichael Widenius3 Jun
        • Re: Drivers giving different resultsTim Bunce3 Jun
          • Re: Drivers giving different resultsMichael Widenius3 Jun
            • Re: Drivers giving different resultsTim Bunce3 Jun
Re: Drivers giving different resultsJochen Wiedmann26 May