Re: Can any_value be used like first_value in an aggregate? - Mailing list pgsql-general

From Bruno Wolff III
Subject Re: Can any_value be used like first_value in an aggregate?
Date
Msg-id 20240627130629.GA1433@wolff.to
Whole thread Raw
In response to Re: Can any_value be used like first_value in an aggregate?  (Laurenz Albe <laurenz.albe@cybertec.at>)
List pgsql-general
On Wed, Jun 26, 2024 at 09:50:59 +0200,
  Laurenz Albe <laurenz.albe@cybertec.at> wrote:
>On Tue, 2024-06-25 at 14:11 -0500, Bruno Wolff III wrote:
>> The actual
>> use case is a set of tripplets returned from a query, where I want on
>> row for each distinct value in the first column, paired with the value
>> in the second column, for which the third column is the largest. The
>> second and third columns are effectively dependent on each other, so there
>> won't be any ambiguity.
>
>Try
>
>  SELECT DISTINCT ON (first_column)
>         first_column,
>         second_column,
>         third_column
>  FROM the_table
>  ORDER BY first_column, third_column DESC;

That approach worked for that part of the query. Thanks.



pgsql-general by date:

Previous
From: Michael Paquier
Date:
Subject: Re: --frokbackend process
Next
From: "agharta82@gmail.com"
Date:
Subject: A way to optimize sql about the last temporary-related row