Re: reuse RECORD in function 'select into'?

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От Rory Campbell-Lange
Тема Re: reuse RECORD in function 'select into'?
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Msg-id 20030527164225.GA2445@campbell-lange.net
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Ответ на Re: reuse RECORD in function 'select into'?  (Josh Berkus <josh@agliodbs.com>)
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Thanks again for your help, Josh.

On 27/05/03, Josh Berkus (josh@agliodbs.com) wrote:
> > In the function below I do four "select into" actions to check if
> > particular values already exist in any one of several tables.
> >
> > Can I reuse the RECORD for each 'select into'? The RECORDs are
> > presumably empty after each select into, as the function needs FOUND to
> > be false to continue.
>
> You certainly can, technically.  In fact, you don't even need the RECORD to be
> empty.

That makes sense, although my "Postgresql Essential Reference" book
selects into an "EmpRec" record. FOUND eq true if one (or more) rows
returned, I see.

> But you want to be *real* careful doing this.  Re-using variables for
> different purposes (in procedural languages), in general, is a very bad idea
> unless you are desperately shourt of memory.   It's far too easy to lose
> track of a re-used variable and waste hours debugging.
>
> O'Reilly's "PL/SQL Programming"  has an excellent chapter on good programming
> practives for SQL-procedural languages that I would love to razor out and
> distribute as a pamphlet.   It would be worth a gander the next time you have
> a long lunch in your local tech book store.

Is this the Oracle PL/SQL book?

--
Rory Campbell-Lange
<rory@campbell-lange.net>
<www.campbell-lange.net>

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