Re: DO ... RETURNING

On Mon, Jun 10, 2013 at 09:23:19PM +0200, Pavel Stehule wrote:
> 2013/6/10 Hannu Krosing <hannu@2ndquadrant.com>:
> > Hallo Everybody
> >
> > As far as I can see, currently you can not return
> > anything out of a DO (anonymous code) block.
> >
> > Something like
> >
> > DO LANGUAGE plpythonu RETURNS TABLE (name text, uid int, gid int) $$
> > with open('/etc/passwd') as f:
> >     fields = f.readline().split(':')
> >     while fields:
> >         name, uid, gid = fields[0], int(fields[2]),int(fields[3])
> >         yield name, uid, gid
> >         fields = f.readline().split(':')
> > $$;
> >
> > As I did not pay attention when DO was introduced,
> > I thought it is faster to ask here than read all possibly
> > relevant mails in archives
> >
> > So: has there been a discussion on extending the DO
> > construct with ability to rturn data out of it, similar
> > to what named functions do.
> >
> > If there was then what were the arguments against doing this ?
> >
> > Or was this just that it was not thought important at that time ?
> 
> I don't like this idea. I know so DO is +/- function, but it is too
> restrict. I hope so we will have a procedures with possibility unbound
> queries.
> 
> and then you can do
> 
> DO $$
>   SELECT * FROM pg_class;
>   SELECT * FROM pg_proc;
>   ...
> $$ LANGUAGE SQL;
> 
> and you don't need to define output structure - what is much more user friendly.

If I understand the proposal correctly, the idea is only to try to
return something when DO is invoked with RETURNING.

1.  Did I understand correctly, Hannu?
2.  If I did, does this alleviate your concerns, Pavel?

Cheers,
David.
-- 
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