Re: shortcut for select * where id in (arrayvar) - Mailing list pgsql-general

From Ivan Sergio Borgonovo
Subject Re: shortcut for select * where id in (arrayvar)
Date
Msg-id 20080331092833.35bb1e1f@webthatworks.it
Whole thread Raw
In response to Re: shortcut for select * where id in (arrayvar)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
On Sun, 30 Mar 2008 21:40:52 -0400
Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Ivan Sergio Borgonovo <mail@webthatworks.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


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