From: Bruce Momjian <bruce@momjian.us>
To: michal.palenik@freemap.sk
To: pgsql-docs@lists.postgresql.org
Subject: Re: nicer examples for aggregate calls
Date: Wed, 31 Aug 2022 22:21:17 -0400
Message-ID: <YxAXHWujeUGa9WpX@momjian.us> (raw)
In-Reply-To: <Yv0VOqChCHRp1nII@momjian.us>
References: <163499710897.684.7420075366995883688@wrigleys.postgresql.org>
<Yv0VOqChCHRp1nII@momjian.us>
On Wed, Aug 17, 2022 at 12:20:10PM -0400, Bruce Momjian wrote:
> On Sat, Oct 23, 2021 at 01:51:48PM +0000, PG Doc comments form wrote:
> > The following documentation comment has been logged on the website:
> >
> > Page: https://www.postgresql.org/docs/14/tutorial-agg.html
> > Description:
> >
> > currently, all of the examples are very simple, like
> >
> > SELECT city, max(temp_lo)
> > FROM weather
> > WHERE city LIKE 'S%' -- (1)
> > GROUP BY city
> > HAVING max(temp_lo) < 40;
> >
> > this example would be more complex and would allow users to search for
> > clause "filter":
> >
> > Finally, if we only care about cities whose names begin with “S” and we want
> > to calculate the number of observations in each city with temp_lo over 30,
> > we might do:
> >
> > SELECT city, max(temp_lo), count(*) filter (temp_lo>30),
> > FROM weather
> > WHERE city LIKE 'S%' -- (1)
> > GROUP BY city
> > HAVING max(temp_lo) < 40;
>
> Good idea. We didn't support FILTER at the time this query was added.
> Here is a patch which adds it.
Patch applied back to PG 10. Thanks.
--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EDB https://enterprisedb.com
Indecision is a decision. Inaction is an action. Mark Batterson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-docs@postgresql.org
Cc: bruce@momjian.us, michal.palenik@freemap.sk, pgsql-docs@lists.postgresql.org
Subject: Re: nicer examples for aggregate calls
In-Reply-To: <YxAXHWujeUGa9WpX@momjian.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox