Re: aggregate functions

> is there any easy way to add the string concatenation operator
> as a collating operator? I would like to do something like:

Blimey, I should have looked for "create aggregate".
But to those interested here is my solution.

create function
joinfunc( text, text )
returns text as '
begin
if $1 = '''' then
return $2;
else
return ( $1 || '', '' ) || $2;
end if;
end;
' language 'plpgsql';

create aggregate join (
basetype = text,
sfunc1 = joinfunc,
stype1 = text,
initcond1 = ''
);

Perhaps someone want to put that into the documentation.
By the way, there is still one problem:

select join(col) group by ...
does not work, one has to type
select "join"(col) group by ...

I assume this is bug ...

Regards,
Holger Klawitter
--
Holger Klawitter +49 (0)251 484 0637
holger(at)klawitter(dot)de http://www.klawitter.de/