Обсуждение: top?

Just wondering if there was a "TOP" equivilant in Postgres?  
IE 
select top 1 * from froo
(only returns 1 row)

TIA
-- 

_________________________
Richard Rowell
rwrowell@bellsouth.net

If Java had true garbage collection, most programs would delete themselves 
upon execution. - Robert Sewell 

On Thu, 3 Jan 2002, Richard Rowell wrote:

> Just wondering if there was a "TOP" equivilant in Postgres?
> IE
> select top 1 * from froo
> (only returns 1 row)

select * from froo limit 1;

Usually you'll want to order as well so that you get a meaningfully
chosen row rather than whatever row happens to be scanned first.

> On Thu, 3 Jan 2002, Richard Rowell wrote:
>
> > Just wondering if there was a "TOP" equivilant in Postgres?
> > IE
> > select top 1 * from froo
> > (only returns 1 row)
>
> select * from froo limit 1;
>
> Usually you'll want to order as well so that you get a meaningfully
> chosen row rather than whatever row happens to be scanned first.

Actually I think its essential that he orders it.  I think the 'top' thing
is a microsoft-ism that gets the 'top 10 items' say from a column.  I can't
remember if it's the 10 with the highest values or the ten with the most
common values...

Chris

TOP works exactly like LIMIT.  In MS SQL you get whatever the first n rows
are returned (no particular order guaranteed).  So unless you want garbage
you have to order your results.

Mike

-----Original Message-----
From: Christopher Kings-Lynne [mailto:chriskl@familyhealth.com.au]
Sent: Thursday, January 03, 2002 7:00 PM
To: Stephan Szabo; Richard Rowell
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] top?


> On Thu, 3 Jan 2002, Richard Rowell wrote:
>
> > Just wondering if there was a "TOP" equivilant in Postgres?
> > IE
> > select top 1 * from froo
> > (only returns 1 row)
>
> select * from froo limit 1;
>
> Usually you'll want to order as well so that you get a meaningfully
> chosen row rather than whatever row happens to be scanned first.

Actually I think its essential that he orders it.  I think the 'top' thing
is a microsoft-ism that gets the 'top 10 items' say from a column.  I can't
remember if it's the 10 with the highest values or the ten with the most
common values...

Chris


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