From: Joe Conway <mail@joeconway.com>
To: Elizabeth O'Neill's Office Mail <elizabeth.oneill@abcmail.co.uk>
Cc: pgsql-sql@postgresql.org
Subject: Re: SQL syntax for concating values in different rows together
Date: Tue, 10 Dec 2002 10:31:41 -0800
Message-ID: <3DF6330D.1090900@joeconway.com> (raw)
In-Reply-To: <BA1B8E36.1C25%elizabeth.oneill@abcmail.co.uk>
References: <BA1B8E36.1C25%elizabeth.oneill@abcmail.co.uk>
Elizabeth O'Neill's Office Mail wrote:
> I have two tables in my database a complaint table and a resolution table.
> One complaint may have several resolutions. I am trying to build a report
> that will give me the complaint details and all the resolution descriptions
> for a complaint in one text area/row (concated together).
>
> At the moment it is repeating the complaint details for each resolution.
As someone else mentioned I think, you can use a plpgsql function. Here is a
contrived example:
create table complaint(cid int, descr text);
insert into complaint values(1,'my #1 complaint');
insert into complaint values(2,'my #2 complaint');
create table resolution(rid int, cid int, res text);
insert into resolution values (1,1,'fixed it');
insert into resolution values (2,1,'really fixed it!');
insert into resolution values (3,2,'pbkbac again');
create or replace function my_concat(int) returns text as'
declare
ret text;
comp text;
rec record;
cntr int = 0;
begin
select into comp descr from complaint where cid = $1;
ret := ''Comp = '' || comp;
for rec in select res from resolution where cid = $1 loop
cntr := cntr + 1;
ret := ret || '': Res# '' || cntr::text || '' = '' || rec.res;
end loop;
return ret;
end;
' language 'plpgsql';
regression=# select my_concat(cid) from complaint;
my_concat
----------------------------------------------------------------------
Comp = my #1 complaint: Res# 1 = fixed it: Res# 2 = really fixed it!
Comp = my #2 complaint: Res# 1 = pbkbac again
(2 rows)
In the past I think I remember someone trying to solve this kind of problem
with a custom aggregate, but the plpgsql approach is probably simpler.
HTH,
Joe
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-sql@postgresql.org
Cc: mail@joeconway.com, elizabeth.oneill@abcmail.co.uk
Subject: Re: SQL syntax for concating values in different rows together
In-Reply-To: <3DF6330D.1090900@joeconway.com>
* 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