Horton

Re: remaining sql/json patches

amit <amitlangote09@gmail.com>

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From: Amit Langote <amitlangote09@gmail.com>
To: jian he <jian.universality@gmail.com>
Cc: Erik Rijkers <er@xs4all.nl>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Andrew Dunstan <andrew@dunslane.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2023-09-19T12:00:02Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. SQL/JSON: Various improvements to SQL/JSON query function docs

  2. SQL/JSON: Fix some obsolete comments.

  3. SQL/JSON: Fix issues with DEFAULT .. ON ERROR / EMPTY

  4. JSON_TABLE: Add support for NESTED paths and columns

  5. Fix JsonExpr deparsing to emit QUOTES and WRAPPER correctly

  6. Fix typo introduced in 6185c9737

  7. Add basic JSON_TABLE() functionality

  8. Avoid splitting errmsg string to span multiple lines

  9. Add SQL/JSON query functions

  10. Implement various jsonpath methods

  11. Add soft error handling to some expression nodes

  12. Adjust populate_record_field() to handle errors softly

  13. Refactor code used by jsonpath executor to fetch variables

  14. Test EXPLAIN (FORMAT JSON) ... XMLTABLE

  15. Simplify productions for FORMAT JSON [ ENCODING name ]

  16. Add trailing commas to enum definitions

  17. doc: add missing <returnvalue> and whitespace

  18. Add more SQL/JSON constructor functions

  19. Rename a nonterminal used in SQL/JSON grammar

  20. Some refactoring to export json(b) conversion functions

  21. Don't include CaseTestExpr in JsonValueExpr.formatted_expr

  22. Code review for commit b6e1157e7d

  23. Pass constructName to transformJsonValueExpr()

  24. Unify JSON categorize type API and export for external use

  25. Make some indentation in gram.y consistent

  26. Allow most keywords to be used as column labels without requiring AS.

  27. Reduce size of backend scanner's tables.

  28. Use perfect hashing, instead of binary search, for keyword lookup.

On Tue, Sep 19, 2023 at 7:37 PM jian he <jian.universality@gmail.com> wrote:
> On Mon, Sep 18, 2023 at 7:51 PM Erik Rijkers <er@xs4all.nl> wrote:
> >
> > and FYI: None of these crashes occur when I leave off the 'WITH WRAPPER'
> > clause.
> >
> > >
> > > Erik
> > >
>
> if specify with wrapper, then default behavior is keep quotes, so
> jexpr->omit_quotes will be false, which make val_string NULL.
> in ExecEvalJsonExprCoercion: InputFunctionCallSafe, val_string is
> NULL, flinfo->fn_strict is true, it will return:  *op->resvalue =
> (Datum) 0. but at the same time  *op->resnull is still false!
>
> if not specify with wrapper, then JsonPathQuery will return NULL.
> (because after apply the path_expression, cannot multiple SQL/JSON
> items)
>
> select json_query(jsonb'{"a":[{"a":3},{"a":[4,5]}]}','$.a[*].a?(@<=3)'
>  returning int4range);
> also make server crash, because default is KEEP QUOTES, so in
> ExecEvalJsonExprCoercion jexpr->omit_quotes will be false.
> val_string will be NULL again as mentioned above.

That's right.

> another funny case:
> create domain domain_int4range int4range;
> select json_query(jsonb'{"a":[{"a":[2,3]},{"a":[4,5]}]}','$.a[*].a?(@<=3)'
>  returning domain_int4range with wrapper);
>
> should I expect it to return  [2,4)  ?

This is what you'll get with v16 that I just posted.

>  -------------------
> https://www.postgresql.org/docs/current/extend-type-system.html#EXTEND-TYPES-POLYMORPHIC
> >>  When the return value of a function is declared as a polymorphic type, there must be at least one argument position that is also
> >> polymorphic, and the actual data type(s) supplied for the polymorphic arguments determine the actual result type for that call.
>
> select json_query(jsonb'{"a":[{"a":[2,3]},{"a":[4,5]}]}','$.a[*].a?(@<=3)'
> returning anyrange);
> should fail. Now it returns NULL. Maybe we can validate it in
> transformJsonFuncExpr?
> -------------------

I'm not sure whether we should make the parser complain about the
weird types being specified in RETURNING.  The NULL you get in the
above example is because of the following error:

select json_query(jsonb'{"a":[{"a":[2,3]},{"a":[4,5]}]}','$.a[*].a?(@<=3)'
returning anyrange error on error);
ERROR:  JSON path expression in JSON_QUERY should return singleton
item without wrapper
HINT:  Use WITH WRAPPER clause to wrap SQL/JSON item sequence into array.

-- 
Thanks, Amit Langote
EDB: http://www.enterprisedb.com