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/