Horton

Re: remaining sql/json patches

jian he <jian.universality@gmail.com>

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From: jian he <jian.universality@gmail.com>
To: Amit Langote <amitlangote09@gmail.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Himanshu Upadhyaya <upadhyaya.himanshu@gmail.com>, Erik Rijkers <er@xs4all.nl>, Andres Freund <andres@anarazel.de>, Andrew Dunstan <andrew@dunslane.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2024-04-06T03:31:22Z
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 Fri, Apr 5, 2024 at 8:35 PM Amit Langote <amitlangote09@gmail.com> wrote:
> Here's one.  Main changes:
>
> * Fixed a bug in get_table_json_columns() which caused nested columns
> to be deparsed incorrectly, something Jian reported upthread.
> * Simplified the algorithm in JsonTablePlanNextRow()
>
> I'll post another revision or two maybe tomorrow, but posting what I
> have now in case Jian wants to do more testing.

i am using the upthread view validation function.
by comparing `execute the view definition` and `select * from the_view`,
I did find 2 issues.

* problem in transformJsonBehavior, JSON_BEHAVIOR_DEFAULT branch.
I think we can fix this problem later, since sql/json query function
already committed?

CREATE DOMAIN jsonb_test_domain AS text CHECK (value <> 'foo');
normally, we do:
SELECT JSON_VALUE(jsonb '{"d1": "H"}', '$.a2' returning
jsonb_test_domain DEFAULT 'foo' ON ERROR);

but parsing back view def, we do:
SELECT JSON_VALUE(jsonb '{"d1": "H"}', '$.a2' returning
jsonb_test_domain DEFAULT 'foo'::text::jsonb_test_domain ON ERROR);

then I found the following two queries should not be error out.
SELECT JSON_VALUE(jsonb '{"d1": "H"}', '$.a2' returning
jsonb_test_domain DEFAULT 'foo1'::text::jsonb_test_domain ON ERROR);
SELECT JSON_VALUE(jsonb '{"d1": "H"}', '$.a2' returning
jsonb_test_domain DEFAULT 'foo1'::jsonb_test_domain ON ERROR);
--------------------------------------------------------------------------------------------------------------------

* problem with type "char". the view def  output is not the same as
the select * from v1.

create or replace view v1 as
SELECT col FROM s,
JSON_TABLE(jsonb '{"d": ["hello", "hello1"]}', '$' as c1
COLUMNS(col "char" path '$.d' without wrapper keep quotes))sub;

\sv v1
CREATE OR REPLACE VIEW public.v1 AS
 SELECT sub.col
   FROM s,
    JSON_TABLE(
            '{"d": ["hello", "hello1"]}'::jsonb, '$' AS c1
            COLUMNS (
                col "char" PATH '$."d"'
            )
        ) sub
one under the hood called JSON_QUERY_OP, another called JSON_VALUE_OP.

I will do extensive checking for other types later, so far, other than
these two issues,
get_json_table_columns is pretty solid, I've tried nested columns with
nested columns, it just works.