Re: [GENERAL] SQL Query

From: A. Kretschmer <andreas.kretschmer(at)schollglas.com>
Date: Wed Dec 05 2007 - 06:15:53 EST

am Wed, dem 05.12.2007, um 10:47:44 +0000 mailte Ashish Karalkar folgendes:
> > X Y
> > ------------
> > 1 ABC
> > 2 PQR
> > 3 XYZ
> > 4 LMN
> > 1 LMN
> > 2 XYZ
> >
> > I want a query that will give me following output
> >
> > 1 ABC:LMN
> > 2 PQR:XYZ
> > 3 XYZ
> > 4 LMN
> >
> > Any help will be really helpful
>
> You need a new aggregate-function. A solution for a similar problem (but
> with comma instead :) can you find here:
> http://www.zigo.dhs.org/postgresql/#comma_aggregate
>
> Thanks Andreas for your replay.
> But i don't have an option two send argument to the store proc nither do i
> know how many multiple records are there for a single X. I want result for
> all rows of table.
>
> I dont thnink that function will give desired output.

test=# create table Ashish ( x int, y text); CREATE TABLE
test=*# copy ashish from stdin;
Enter data to be copied followed by a newline. End with a backslash and a period on a line by itself.

>> 1    abc
>> 2    pqr
>> 3    yxz
>> 4    lmn
>> 1    lmn
>> 2    xyz
>> \.

test=*# CREATE FUNCTION my_aggregate(text,text) RETURNS text AS ' SELECT CASE WHEN $1 <> '''' THEN $1 || '':'' || $2 ELSE $2 END; ' LANGUAGE sql IMMUTABLE STRICT; CREATE AGGREGATE my_comma (basetype=text, sfunc=my_aggregate , stype=text, initcond='' ); CREATE FUNCTION
CREATE AGGREGATE
test=*# select x, my_comma(y) from ashish group by x;  x | my_comma
---+----------

 4 | lmn
 3 | yxz
 2 | pqr:xyz
 1 | abc:lmn

(4 rows)

Okay, i forgot to sort and the chars are in lower case...

Andreas

-- 
Andreas Kretschmer
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Received on Wed Dec 5 06:17:09 2007