Re: shortcut for select * where id in (arrayvar)

[Ivan Sergio Borgonovo <mail(at)webthatworks(dot)it>]

On Sun, 30 Mar 2008 21:40:52 -0400
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Ivan Sergio Borgonovo <mail(at)webthatworks(dot)it> writes:
> > for _row in
> > 	select err, msg from errortable where err in (errcode)
> 
> > where errcode is an array.
> > That syntax doesn't work...

> In recent PG releases it will work as "WHERE err = ANY (errcode)"
> but note that there is *no* guarantee that the select will deliver
> the rows in the same order the array elements are in.


That's exactly what I was looking for.

array_to_string is not as type safe as ANY and I didn't check how it
may behave in a situation similar to:

select * from array_to_string(ARRAY['ciao','pota\'z'],',');

What I came up is

create table errors (errcode int, errmsg varchar(255));
insert into errors values(1,'ciao1');
insert into errors values(2,'ciao2');
insert into errors values(3,'ciao3');
insert into errors values(4,'ciao4');


create or replace function auz(out _errcode int, out _errmsg text)
returns setof record as $$
declare
	__errcode int[];
	_row record;
begin
	-- these should be function calls
	-- eg. __errcode[1]:=somechk(param1, param2);
	__errcode[1]:=1;
	__errcode[2]:=3;
	for _row in
	  select errcode, errmsg
	   from errors where errcode = any (__errcode) loop
		_errcode:=_row.errcode;
		_errmsg:=_row.errmsg;
		return next;
	end loop;
	return;
end;
$$ language plpgsql;

I'm still thinking if this should be the way to report a list of
failed tests.

Maybe I could just hard code the error message in the checking
function.

-- 
Ivan Sergio Borgonovo
http://www.webthatworks.it