Message-ID: <9be7b272-aca6-485b-bec7-386997c7970c@dunslane.net>
Date: Thu, 26 Sep 2024 13:16:38 -0400
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Subject: Re: SQL:2023 JSON simplified accessor support
To: Alexandra Wang <alexandra.wang.oss@gmail.com>,
 Peter Eisentraut <peter@eisentraut.org>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
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From: Andrew Dunstan <andrew@dunslane.net>
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On 2024-09-26 Th 11:45 AM, Alexandra Wang wrote:
> Hi,
>
> I didn’t run pgindent earlier, so here’s the updated version with the
> correct indentation. Hope this helps!


This is a really nice feature, and provides a lot of expressive power 
for such a small piece of code.

I notice this doesn't seem to work for domains over json and jsonb.


andrew@~=# create domain json_d as json;
CREATE DOMAIN
andrew@~=# create table test_json_dot(id int, test_json json_d);
CREATE TABLE
andrew@~=# insert into test_json_dot select 1, '{"a": 1, "b": 42}'::json;
INSERT 0 1      |          |
andrew@~=# select (test_json_dot.test_json).b, json_query(test_json, 
'lax $.b' WITH CONDITIONAL WRAPPER NULL ON EMPTY NULL ON ERROR) as 
expected from test_json_dot;
ERROR:  column notation .b applied to type json_d, which is not a 
composite type
LINE 1: select (test_json_dot.test_json).b, json_query(test_json, 'l...


I'm not sure that's a terribly important use case, but we should 
probably make it work. If it's a domain we should get the basetype of 
the domain. There's some example code in src/backend/utils/adt/jsonfuncs.c


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com