Re: SQL query help - online music shop - labels & styles

> > BUT! How can I achieve the following??
> > --------------------------------
> > label | style1 | style2 | style3
> > -------------------------------
> > Matsuri Productions | House | Techno | Trance
>
>
> Several times I asked if there is a SQL-way to transpone.
> As I didn't get an answer I believe the answer is no.

[...]

> Perhaps it is possible to write a plpgsql-function for it,
> but propably it's not worth the effort.
>

I faced the same problem a few days ago; my case was pretty easy to
solve: first create a function that join the arguments with, say, a
blank space:

create function concat(text,text) returns text as 'select (case when
$1 <> '''' then $1 || '' '' else $1 end) || $2' language 'sql';

create an aggregate function. Something like:

create aggregate concat_agg (
basetype = text,
sfunc = concat,
stype = text,
initcond = ''
);

create a temporal test table and insert some values:

create table tmp(name text, token text);
insert into tmp values ('masm','lola');
insert into tmp values ('masm','dola');
insert into tmp values ('masm','mola');
insert into tmp values ('masm','pola');
insert into tmp values ('jsf','kola');
insert into tmp values ('jsf','dona');
insert into tmp values ('jsf','poca');

and then select and group by according to your needs:

regression=# select name,concat_agg(token) from tmp group by name;
name | concat_agg
------+---------------------
jsf | kola dona poca
masm | lola dola mola pola
(2 rows)
regression=#

HTH,
Manuel.