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* Random sort with distinct
@ 2010-10-01 20:51 Ozer, Pam <pozer@automotive.com>
0 siblings, 3 replies; 5+ messages in thread
From: Ozer, Pam @ 2010-10-01 20:51 UTC (permalink / raw)
To: pgsql-sql
I have the following query
Select Distinct VehicleMake, VehicleModel
From VehicleYearMakeModelTrim
Order by random()
Limit 10;
I don't want to bring back the random number I just want the sort order
to be random. How can I sort randomly? This query breaks because
random() is not in the select.
Thanks
Pam
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Random sort with distinct
@ 2010-10-02 13:40 Dmitriy Igrishin <dmitigr@gmail.com>
parent: Ozer, Pam <pozer@automotive.com>
2 siblings, 1 reply; 5+ messages in thread
From: Dmitriy Igrishin @ 2010-10-02 13:40 UTC (permalink / raw)
To: Ozer, Pam <pozer@automotive.com>; +Cc: pgsql-sql
Hey Ozer,
How about dynamic queries?
2010/10/2 Ozer, Pam <pozer@automotive.com>
> I have the following query
>
>
>
> Select Distinct VehicleMake, VehicleModel
>
> From VehicleYearMakeModelTrim
>
> Order by random()
>
> Limit 10;
>
>
>
> I don’t want to bring back the random number I just want the sort order to
> be random. How can I sort randomly? This query breaks because random() is
> not in the select.
>
>
>
> Thanks
>
>
>
> Pam
>
>
>
>
--
// Dmitriy.
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Random sort with distinct
@ 2010-10-02 13:42 Lee Hachadoorian <lee.hachadoorian@gmail.com>
parent: Ozer, Pam <pozer@automotive.com>
2 siblings, 0 replies; 5+ messages in thread
From: Lee Hachadoorian @ 2010-10-02 13:42 UTC (permalink / raw)
To: pgsql-sql
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This runs fine on my 8.4 install. What version are you using and what
error message are you getting?<br>
<br>
--Lee<br>
<br>
On 10/01/2010 04:51 PM, Ozer, Pam wrote:
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<p class="MsoNormal">I have the following query<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Select Distinct VehicleMake, VehicleModel<o:p></o:p></p>
<p class="MsoNormal">From VehicleYearMakeModelTrim<o:p></o:p></p>
<p class="MsoNormal">Order by random()<o:p></o:p></p>
<p class="MsoNormal">Limit 10;<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I don’t want to bring back the random number I
just
want the sort order to be random. How can I sort randomly? This query
breaks
because random() is not in the select.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Pam<o:p></o:p></p>
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<br>
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<br>
<pre class="moz-signature" cols="72">--
Lee Hachadoorian
PhD Student, Geography
Program in Earth & Environmental Sciences
CUNY Graduate Center
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^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Random sort with distinct
@ 2010-10-02 13:52 Tom Lane <tgl@sss.pgh.pa.us>
parent: Ozer, Pam <pozer@automotive.com>
2 siblings, 0 replies; 5+ messages in thread
From: Tom Lane @ 2010-10-02 13:52 UTC (permalink / raw)
To: Ozer, Pam <pozer@automotive.com>; +Cc: pgsql-sql
"Ozer, Pam" <pozer@automotive.com> writes:
> Select Distinct VehicleMake, VehicleModel
> From VehicleYearMakeModelTrim
> Order by random()
> Limit 10;
> I don't want to bring back the random number I just want the sort order
> to be random. How can I sort randomly? This query breaks because
> random() is not in the select.
Well, yeah: the implication of the ORDER BY is that a new random value
is to be computed for each row of VehicleYearMakeModelTrim. After you
combine rows with DISTINCT it's not clear which of those values should
be used to sort a grouped row.
You need to put the DISTINCT and the ORDER BY in separate query levels,
like this:
select * from
(Select Distinct VehicleMake, VehicleModel
From VehicleYearMakeModelTrim) ss
Order by random()
Limit 10;
regards, tom lane
^ permalink raw reply [nested|flat] 5+ messages in thread
* Re: Random sort with distinct
@ 2010-10-04 15:40 Ozer, Pam <pozer@automotive.com>
parent: Dmitriy Igrishin <dmitigr@gmail.com>
0 siblings, 0 replies; 5+ messages in thread
From: Ozer, Pam @ 2010-10-04 15:40 UTC (permalink / raw)
To: Dmitriy Igrishin <dmitigr@gmail.com>; +Cc: pgsql-sql
What about dynamic queries?
From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-owner@postgresql.org] On Behalf Of Dmitriy Igrishin
Sent: Saturday, October 02, 2010 6:40 AM
To: Ozer, Pam
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] Random sort with distinct
Hey Ozer,
How about dynamic queries?
2010/10/2 Ozer, Pam <pozer@automotive.com>
I have the following query
Select Distinct VehicleMake, VehicleModel
From VehicleYearMakeModelTrim
Order by random()
Limit 10;
I don’t want to bring back the random number I just want the sort order to be random. How can I sort randomly? This query breaks because random() is not in the select.
Thanks
Pam
--
// Dmitriy.
^ permalink raw reply [nested|flat] 5+ messages in thread
end of thread, other threads:[~2010-10-04 15:40 UTC | newest]
Thread overview: 5+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2010-10-01 20:51 Random sort with distinct Ozer, Pam <pozer@automotive.com>
2010-10-02 13:40 ` Dmitriy Igrishin <dmitigr@gmail.com>
2010-10-04 15:40 ` Ozer, Pam <pozer@automotive.com>
2010-10-02 13:42 ` Lee Hachadoorian <lee.hachadoorian@gmail.com>
2010-10-02 13:52 ` Tom Lane <tgl@sss.pgh.pa.us>
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