Re: Emitting JSON to file using COPY TO

On 2024-Jan-23, jian he wrote:

> > +           | FORMAT_LA copy_generic_opt_arg
> > +               {
> > +                   $$ = makeDefElem("format", $2, @1);
> > +               }
> >         ;
> >
> > I think it's not necessary. "format" option is already handled in
> > copy_generic_opt_elem.
> 
> test it, I found out this part is necessary.
> because a query with WITH like `copy (select 1)  to stdout with
> (format json, force_array false); ` will fail.

Right, because "FORMAT JSON" is turned into FORMAT_LA JSON by parser.c
(see base_yylex there).  I'm not really sure but I think it might be
better to make it "| FORMAT_LA JSON" instead of invoking the whole
copy_generic_opt_arg syntax.  Not because of performance, but just
because it's much clearer what's going on.

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/