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Re: SQL/JSON: functions

Erik Rijkers <er@xs4all.nl>

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From: Erik Rijkers <er@xs4all.nl>
To: Nikita Glukhov <n.gluhov@postgrespro.ru>
Cc: Zhihong Yu <zyu@yugabyte.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Michael Paquier <michael@paquier.xyz>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, Justin Pryzby <pryzby@telsasoft.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>, Pavel Stehule <pavel.stehule@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Thomas Munro <thomas.munro@gmail.com>, Andrew Alsup <bluesbreaker@gmail.com>, Andres Freund <andres@anarazel.de>, Dmitry Dolgov <9erthalion6@gmail.com>, Oleg Bartunov <obartunov@postgrespro.ru>, Simon Riggs <simon@2ndquadrant.com>
Date: 2021-01-23T10:37:41Z
Lists: pgsql-hackers

Attachments

On 2021-01-20 03:49, Nikita Glukhov wrote:

> [0001-Add-common-SQL-JSON-clauses-v52.patch.gz]
> [0002-SQL-JSON-constructors-v52.patch.gz]
> [0003-IS-JSON-predicate-v52.patch.gz]
> [0004-SQL-JSON-query-functions-v52.patch.gz]
> [0005-SQL-JSON-functions-for-json-type-v52.patch.gz]
> [0006-GUC-sql_json-v52.patch.gz]

Hi,

I read through the file func.sgml (only that file) and put the 
errors/peculiarities in the attached diff.  (Small stuff; typos really)


Your patch includes a CREATE TABLE my_films + INSERT, to run the 
examples against.  I think this is a great idea and we should do it more 
often.

But, the table has a text-column to contain the subsequently inserted 
json values. The insert runs fine but it turns out that some later 
examples queries only run against a jsonb column.  So I propose to 
change:
   CREATE TABLE my_films (js text);
to:
   CREATE TABLE my_films (js jsonb);

This change is not yet included in the attached file.  An alternative 
would be to cast the text-column in the example queries as js::jsonb


I also noticed that some errors were different in the sgml file than 'in 
the event':


    SELECT JSON_QUERY(js, '$.favorites[*].kind' ERROR ON ERROR) FROM 
my_films_jsonb;
    (table 'my_films_jsonb' is the same as your 'my_films', but with js 
as a jsonb column)

manual says: "ERROR: more than one SQL/JSON item"
  in reality: "ERROR: JSON path expression in JSON_QUERY should return 
singleton item without wrapper"
         and:   "HINT: use WITH WRAPPER clause to wrap SQL/JSON item 
sequence into array"


Thanks,

Erik Rijkers

> 
> --
> Nikita Glukhov
> Postgres Professional: http://www.postgrespro.com
> The Russian Postgres Company

Commits

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

  1. JSON_TABLE: Add support for NESTED paths and columns

  2. Add basic JSON_TABLE() functionality

  3. Add SQL/JSON query functions

  4. Add soft error handling to some expression nodes

  5. Adjust populate_record_field() to handle errors softly

  6. Refactor code used by jsonpath executor to fetch variables

  7. Add more SQL/JSON constructor functions

  8. SQL/JSON: support the IS JSON predicate

  9. SQL/JSON: add standard JSON constructor functions

  10. Improve readability of SQL/JSON documentation.

  11. Documentation for SQL/JSON features

  12. RETURNING clause for JSON() and JSON_SCALAR()

  13. SQL JSON functions

  14. SQL/JSON query functions

  15. IS JSON predicate

  16. SQL/JSON constructors

  17. Common SQL/JSON clauses

  18. Doc: remove obsolete entries in table of BRIN strategy numbers.

  19. Doc: standardize markup a bit more.

  20. Make pg_regress.c unset PGDATABASE during make installcheck.

  21. Fix handling of GENERATED columns in CREATE TABLE LIKE INCLUDING DEFAULTS.