Re: Select first ten of each category?

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От Brent Wood
Тема Re: Select first ten of each category?
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Msg-id 20060413140948.G76831@storm-user.niwa.co.nz
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Ответ на Select first ten of each category?  (Benjamin Smith <lists@benjamindsmith.com>)
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On Wed, 12 Apr 2006, Benjamin Smith wrote:

> I'm stumped on this one...
>
> I have a table defined thusly:
>
> create table items (
> id serial,
> category integer not null references category(id),
> name varchar not null,
> price real,
> unique(category, name));



I think this should work....

select * from items
order by price desc
limit 10;


Cheers,

  Brent Wood

>
> It has a LARGE number of entries. I'd like to grab the 10 most expensive items
> from each category in a single query. How can this be done? Something like
>
> Select items.*
> FROM items
> where id IN (
>     select firstTen(id) FROM items
>     group by category
>     ORDER BY price DESC
>     )
> ORDER BY price desc;
>
> But I've not found any incantation to make this idea work...
>

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