Re: Extract numeric filed in JSONB more effectively

Hi jian:

On Thu, Aug 17, 2023 at 12:32 AM jian he <jian.universality@gmail.com>
wrote:

> On Wed, Aug 16, 2023 at 2:28 PM Andy Fan <zhihui.fan1213@gmail.com> wrote:
> >
> > update with the correct patch..
>
> regression=# select proname, pg_catalog.pg_get_function_arguments(oid)
> from pg_proc
> where proname =  'jsonb_extract_path_type';
>          proname         |                     pg_get_function_arguments
>
> -------------------------+--------------------------------------------------------------------
>  jsonb_extract_path_type | from_json jsonb, VARIADIC path_elems
> text[], target_oid anyelement
> (1 row)
>
> VARIADIC should be the last argument?
>

Currently if users call this function directly(usually I don't  think
so), they will get something wrong.   This issue is fixed in the
v9 version.  To keep the consistency among all the functions,
I moved the 'target_type anyelement' to the 1st argument.
Thanks for the report!


> select jsonb_array_element_type(jsonb'[1231]',0, null::int);
> now return null.
> Should it return 1231?
>

No, this is by design. the function is declared as strict, so
any NULL inputs yield a NULL output.  That's just what we
talked above (the markDummyConst section).  I don't
think this should be addressed.


> select jsonb_array_element_type(jsonb'[1231]',0, '1'::jsonb);
> will crash
>

OK,  looks I didn't pay enough attention to the 'user directly call
jsonb_xx_type' function, so I changed the code in v9 based on
your suggestion.

Thanks for the review,  v9 attached!

-- 
Best Regards
Andy Fan