From: Martin Stöcker <martin.stoecker@stb-datenservice.de>
To: pgsql-sql@lists.postgresql.org
Subject: Re: Group By aggregate string function
Date: Thu, 21 Feb 2019 21:06:15 +0100
Message-ID: <f5280ca9-f039-d7a7-403e-d8b338aa7d5f@stb-datenservice.de> (raw)
In-Reply-To: <730D7ADD-A08D-4EA2-A4B0-7C7EF7ABC4CB@illinois.edu>
References: <04E1F4B6-7092-4338-B97D-EC495C5F1B1E@illinois.edu>
<730D7ADD-A08D-4EA2-A4B0-7C7EF7ABC4CB@illinois.edu>
Hi Lance
first of all you should check your data-model.
If there are different roles or jobs in a certain order, you should
better bring these jobs in theier own table.
So it is easy to have them ordered.
But you can do some tricks to treat them as array elements
Not nice but it works
create table staff(id integer, user text, job text);
insert some data ...
select id, usr, ar[pos] from (select id, usr,
min(array_position(array['admin', 'manager'], job)) as pos,
array['admin', 'manager'] as ar from staff where usr='lance' group by
id, usr, ar)
as test;
id | usr | ar
----+-------+-------
1 | lance | admin
Regards Martin
Am 21.02.2019 um 20:02 schrieb Campbell, Lance:
>
> Correction. I had two typos. I did not want to confuse someone.
>
> PostgreSQL 10.x
>
> Below is my situation. I need some kind of aggregate string function
> that when it finds multiple string values it will order them based on
> a preferred preference. Example: “admin”, then “manager” then “…”.
>
> Table T
>
> fk_id int – foreign key
>
> user_id text
>
> role text - possible values could be “admin” and “manager”
>
> Primary key (fk_id, user_id, role)
>
> Sample data:
>
> 1. lance admin
>
> 1 lance manager
>
> 87 bob manager
>
> 98 tom admin
>
> 104 tom manager
>
> SELECT fk_id, user_id, some-aggregate-string-function(role, “admin”,
> “manager”) FROM T WHERE user_id = ‘lance’ GROUP BY fk_id, user_id;
>
> When selecting data if there are multiple rows within the group by
> then aggregate the result based on a priority for role of “admin”
> first, “manager” second, etc.
>
> Expected Result:
>
> 1 lance admin
>
> Ignores the second record with lance in it because the first record
> contained admin.
>
> THANKS!
>
> *From: *Lance Campbell <lance@illinois.edu>
> *Date: *Thursday, February 21, 2019 at 1:00 PM
> *To: *"pgsql-sql@postgresql.org" <pgsql-sql@postgresql.org>
> *Subject: *Group By aggregate string function
>
> PostgreSQL 10.x
>
> Below is my situation. I need some time of aggregate string function
> that when it finds multiple string values it will order them based on
> a preferred preference. Example: “admin”, then “manager” then “…”.
>
> Table T
>
> fk_id int – foreign key
>
> user_id text
>
> role text - possible values could be “admin” and “manager”
>
> Primary key (fk_id, user_id, role)
>
> Sample data:
>
> 1. lance admin
>
> 1 lance manager
>
> 87 bob manager
>
> 98 tom admin
>
> 104 tom manager
>
> SELECT fk_id, user_id, some-aggregate-string-function(role, “admin”,
> “manager”) FROM T WHERE user_id = ‘lance’ GROUP BY fk_id, user_id;
>
> When selecting data if there are multiple rows within the group by
> then aggregate the result based on a priority for role of “admin”
> first, “manager” second, etc.
>
> Expected Result:
>
> 1 lance admin
>
> Ignores the second record with lance in it because it contains admin.
>
> THANKS!
>
> *LANCE CAMPBELL <https://directory.illinois.edu/person/lance>*
>
> /Software Architect/
>
> Web Services <https://webtools.illinois.edu/;
>
> Public Affairs <https://publicaffairs.illinois.edu/;
>
> Contact the Webtools Team <https://go.illinois.edu/contactUs;
>
> 217.333.0382
>
> lance@illinois.edu <mailto:lance@illinois.edu>
>
> /var/folders/wp/1f6l7hw95y718z976kgnl5f9kr5rtc/T/com.microsoft.Outlook/WebArchiveCopyPasteTempFiles/signature_logo.png
> <http://illinois.edu/;
>
> /Under the Illinois Freedom of Information Act any written
> communication to or from university employees regarding university
> business is a public record and may be subject to public disclosure./
>
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To: pgsql-sql@postgresql.org
Cc: martin.stoecker@stb-datenservice.de, pgsql-sql@lists.postgresql.org
Subject: Re: Group By aggregate string function
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