From: Bruno Wolff III <bruno@wolff.to>
To: C F <tacnaboyz@yahoo.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: SQL Help
Date: Fri, 30 May 2003 11:30:40 -0500
Message-ID: <20030530163040.GA22409@wolff.to> (raw)
In-Reply-To: <20030530154703.37238.qmail@web20415.mail.yahoo.com>
References: <20030530154703.37238.qmail@web20415.mail.yahoo.com>
On Fri, May 30, 2003 at 08:47:03 -0700,
C F <tacnaboyz@yahoo.com> wrote:
> Hello,
> I already tried this same basic question with no response.... maybe I was too wordy. So here it is simplified.... what's the best way to write this query? I'm open to using stored procedures, but even then I don't know how I would conditionally populate a resultset (refcursor). Notice that in the first three cases, the expression is the exact same, only the return value is different. This seems inefficient....
>
>
> select
> (case when column1 = column2 then column3 end) as alias1,
> (case when column1 = column2 then column4 end) as alias2,
> (case when column1 = column2 then column5 end) as alias3,
> (case when column6 = column7 then column8 end) as alias4
> from
> mytable
> ;
That seems pretty efficient. I wouldn't expect the repeated column1 = column2
tests to add much overhead. Unless there is more to the story this looks
to be what you want to do.
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To: pgsql-sql@postgresql.org
Cc: bruno@wolff.to, tacnaboyz@yahoo.com
Subject: Re: SQL Help
In-Reply-To: <20030530163040.GA22409@wolff.to>
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