Re: sql/json remaining issue

Hi,

On Sat, Apr 13, 2024 at 11:12 PM jian he <jian.universality@gmail.com> wrote:
> On Fri, Apr 12, 2024 at 5:44 PM Amit Langote <amitlangote09@gmail.com> wrote:
> >
> > > elog(ERROR, "unrecognized json wrapper %d", wrapper);
> > > should be
> > > elog(ERROR, "unrecognized json wrapper %d", (int) wrapper);
> >
> > Fixed in 0003.
> >
> the fix seems not in 0003?
> other than that, everything looks fine.
>
>
> <programlisting>
> SELECT * FROM JSON_TABLE (
> '{"favorites":
>     {"movies":
>       [{"name": "One", "director": "John Doe"},
>        {"name": "Two", "director": "Don Joe"}],
>      "books":
>       [{"name": "Mystery", "authors": [{"name": "Brown Dan"}]},
>        {"name": "Wonder", "authors": [{"name": "Jun Murakami"},
> {"name":"Craig Doe"}]}]
> }}'::json, '$.favs[*]'
> COLUMNS (user_id FOR ORDINALITY,
>   NESTED '$.movies[*]'
>     COLUMNS (
>     movie_id FOR ORDINALITY,
>     mname text PATH '$.name',
>     director text),
>   NESTED '$.books[*]'
>     COLUMNS (
>       book_id FOR ORDINALITY,
>       bname text PATH '$.name',
>       NESTED '$.authors[*]'
>         COLUMNS (
>           author_id FOR ORDINALITY,
>           author_name text PATH '$.name'))));
> </programlisting>
>
> I actually did run the query, it returns null.
> '$.favs[*]'
> should be
> '$.favorites[*]'

Oops, fixed.

I've combined these patches into one -- attached 0001.  Will push tomorrow.

> one more minor thing, I previously mentioned in getJsonPathVariable
> ereport(ERROR,
> (errcode(ERRCODE_UNDEFINED_OBJECT),
> errmsg("could not find jsonpath variable \"%s\"",
> pnstrdup(varName, varNameLength))));
>
> do we need to remove pnstrdup?

Looking at this again, it seems like that's necessary because varName,
being a string extracted from JsonPathItem, is not necessarily
null-terminated.  There are many pndstrdup()s in jsonpath_exec.c
because of that aspect.

Now studying the JsonBehavior DEFAULT expression issue and your patch.

--
Thanks, Amit Langote