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Re: SQL:2023 JSON simplified accessor support

David G. Johnston <david.g.johnston@gmail.com>

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From: "David G. Johnston" <david.g.johnston@gmail.com>
To: Chao Li <li.evan.chao@gmail.com>
Cc: Alexandra Wang <alexandra.wang.oss@gmail.com>, Nikita Glukhov <glukhov.n.a@gmail.com>, jian he <jian.universality@gmail.com>, Nikita Malakhov <hukutoc@gmail.com>, Vik Fearing <vik@postgresfriends.org>, Mark Dilger <mark.dilger@enterprisedb.com>, Matheus Alcantara <matheusssilv97@gmail.com>, Peter Eisentraut <peter@eisentraut.org>, Andrew Dunstan <andrew@dunslane.net>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, "David E. Wheeler" <david@justatheory.com>
Date: 2025-09-02T03:53:34Z
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. Add test coverage for indirection transformation

  2. Fix typo in comment

  3. Implementation of subscripting for jsonb

On Monday, September 1, 2025, Chao Li <li.evan.chao@gmail.com> wrote:

>
> The last comment is about error message:
>
> ```
> evantest=# select data.a from test_jsonb_types;
> ERROR:  missing FROM-clause entry for table "data"
> LINE 1: select data.a from test_jsonb_types;
> ```
>
> “Missing FROM-clause entry” is quite confusing and not providing much
> useful hint to resolve the problem. When I first saw this error, I was
> stuck. Only after read through the commit comments, I figured out the
> problem. For end users, we should provide some more meaningful error
> messages.
>
>
I don’t think it’s fair to blame this patch set for this.  If you want to
reference a component of a composite column you need to write
([tbl.]col).field otherwise the parser gets confused because it wants the
thing prior to “field” to be a table name if you don’t use the
parentheses.  This comes up all the time if one uses composite typed
columns.  I’ll agree this isn’t the greatest error message but I’d suggest
starting a new thread if you want to see about improving it.

David J.