From: | "Harald Armin Massa" <haraldarminmassa(at)gmail(dot)com> |
---|---|
To: | "Kynn Jones" <kynnjo(at)gmail(dot)com> |
Cc: | "pgsql-general General" <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: How to select rows that are the max for each subcategory? |
Date: | 2008-09-25 18:05:49 |
Message-ID: | 7be3f35d0809251105v453e46a3g423f16aae6be59a8@mail.gmail.com |
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Lists: | pgsql-general |
select x,y,z
from
t join (select x, max(y) as my from t group by x) t1 on (t.x=t1.x and t.y=t1.my)
best wishes
Harald
On Thu, Sep 25, 2008 at 20:01, Kynn Jones <kynnjo(at)gmail(dot)com> wrote:
> Suppose I have a table T that has, among its columns, the fields X and Y,
> where Y is an integer, and multiple rows with the same value of X are
> possible. I want to select the rows corresponding to the greatest values of
> Y for each value of X. E.g. suppose that T is
> X Y Z
> a 1 eenie
> a 3 meenie
> a 2 miny
> b 4 moe
> b 0 catch
> ...the result of the desired query would be
> a 3 meenie
> b 4 moe
> TIA!
> Kynnjo
>
>
>
--
GHUM Harald Massa
persuadere et programmare
Harald Armin Massa
Spielberger Straße 49
70435 Stuttgart
0173/9409607
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