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>, Andres Freund <andres@anarazel.de>, Andrew Dunstan <andrew@dunslane.net>, Erik Rijkers <er@xs4all.nl>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Tomas Vondra <tomas.vondra@enterprisedb.com>
Date: 2024-03-11T03:30:09Z
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 Sun, Mar 10, 2024 at 10:57 PM jian he <jian.universality@gmail.com> wrote:
>
> one more issue.

Hi
one more documentation issue.
after applied V42, 0001 to 0003,
there are 11 appearance of `FORMAT JSON` in functions-json.html
still not a single place explained what it is for.

json_query ( context_item, path_expression [ PASSING { value AS
varname } [, ...]] [ RETURNING data_type [ FORMAT JSON [ ENCODING UTF8
] ] ] [ { WITHOUT | WITH { CONDITIONAL | [UNCONDITIONAL] } } [ ARRAY ]
WRAPPER ] [ { KEEP | OMIT } QUOTES [ ON SCALAR STRING ] ] [ { ERROR |
NULL | EMPTY { [ ARRAY ] | OBJECT } | DEFAULT expression } ON EMPTY ]
[ { ERROR | NULL | EMPTY { [ ARRAY ] | OBJECT } | DEFAULT expression }
ON ERROR ])

FORMAT JSON seems just a syntax sugar or for compatibility in json_query.
but it returns an error when the returning type category is not
TYPCATEGORY_STRING.

for example, even the following will return an error.
`
CREATE TYPE regtest_comptype AS (b text);
SELECT JSON_QUERY(jsonb '{"a":{"b":"c"}}', '$.a' RETURNING
regtest_comptype format json);
`

seems only types in[0] will not generate an error, when specifying
FORMAT JSON in JSON_QUERY.

so it actually does something, not a syntax sugar?

[0] https://www.postgresql.org/docs/current/datatype-character.html