RE: SQL performance question 1

["Christen, Duane J." <Duane.Christen@xxxxxxxxxxxxx>]

And don't use "If uslessfield = 1" to determine if a record is found use "If sqlcod > 0 and sqlcod <> 100".

Duane Christen

> -----Original Message-----
> From: rpg400-l-bounces@xxxxxxxxxxxx
> [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of
> Tommy.Holden@xxxxxxxxxxxxxxxxxxxxx
> Sent: Thursday, December 18, 2008 8:25 AM
> To: RPG programming on the IBM i / System i
> Subject: Re: SQL performance question 1
>
> SETLL would be better in this case...but if you want to use
> the SQL for this (yuck) i'd use something like this
>
> Exec SQL
> Select 1 into :uselessfield from myfile where key = :hostvar;
>
>
> Thanks,
> Tommy Holden
>
>
>
> From:
> David FOXWELL <David.FOXWELL@xxxxxxxxx>
> To:
> RPG programming on the IBM i / System i <rpg400-l@xxxxxxxxxxxx>
> Date:
> 12/18/2008 08:12 AM
> Subject:
> SQL performance question 1
> Sent by:
> rpg400-l-bounces@xxxxxxxxxxxx
>
>
>
> Hi,
>
> A lot of our developers have recently been introducing SQL
> into their RPG code.
>
> We've had a discussion to see how SQL is being implemented.
>
> A lot have replaced this kind of loop:
>
> SETLL key file
> dou %eof(file)
> READE key file
> if %eof
>    iter
> endif
>
> If condition
>     indicateur = *on
>     leave
> endif
> enddo
>
> to see if a row exists, by this :
>
> Select count(*) from myfile where key = : hostvar
>
> I have advised :
>
> Select key from myfile where key = : hostvar fetch first row only.
>
>
> Is there a better way? Is this a standard way to see if a row
> exists? I know there is EXISTS( ) but that would be the same
> request (according to visual explain).
>
> Does the RPG version still have any advantages?
>
> Thanks.
>
>
>
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