Horton

Re: More new SQL/JSON item methods

Peter Eisentraut <peter@eisentraut.org>

View thread
From: Peter Eisentraut <peter@eisentraut.org>
To: Jeevan Chalke <jeevan.chalke@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-10-06T11:43:44Z
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. Rationalize and improve error messages for some jsonpath items

  2. Clean up a bug in sql/json items commit 66ea94e8e6

  3. Implement various jsonpath methods

  4. Reorganise jsonpath operators and methods

  5. Add numeric_int8_opt_error() to optionally suppress errors

On 29.08.23 09:05, Jeevan Chalke wrote:
> v1-0001-Implement-jsonpath-.bigint-.integer-and-.number-m.patch
> 
> This commit implements jsonpath .bigint(), .integer(), and .number()
> methods.  The JSON string or a numeric value is converted to the
> bigint, int4, and numeric type representation.

A comment that applies to all of these: These add various keywords, 
switch cases, documentation entries in some order.  Are we happy with 
that?  Should we try to reorder all of that for better maintainability 
or readability?

> v1-0002-Implement-.date-.time-.time_tz-.timestamp-and-.ti.patch
> 
> This commit implements jsonpath .date(), .time(), .time_tz(),
> .timestamp(), .timestamp_tz() methods.  The JSON string representing
> a valid date/time is converted to the specific date or time type
> representation.
> 
> The changes use the infrastructure of the .datetime() method and
> perform the datatype conversion as appropriate.  All these methods
> accept no argument and use ISO datetime formats.

These should accept an optional precision argument.  Did you plan to add 
that?

> v1-0003-Implement-jsonpath-.boolean-and-.string-methods.patch
> 
> This commit implements jsonpath .boolean() and .string() methods.

This contains a compiler warning:

../src/backend/utils/adt/jsonpath_exec.c: In function 
'executeItemOptUnwrapTarget':
../src/backend/utils/adt/jsonpath_exec.c:1162:86: error: 'tmp' may be 
used uninitialized [-Werror=maybe-uninitialized]

> v1-0004-Implement-jasonpath-.decimal-precision-scale-meth.patch
> 
> This commit implements jsonpath .decimal() method with optional
> precision and scale.  If precision and scale are provided, then
> it is converted to the equivalent numerictypmod and applied to the
> numeric number.

This also contains compiler warnings:

../src/backend/utils/adt/jsonpath_exec.c: In function 
'executeItemOptUnwrapTarget':
../src/backend/utils/adt/jsonpath_exec.c:1403:53: error: declaration of 
'numstr' shadows a previous local [-Werror=shadow=compatible-local]
../src/backend/utils/adt/jsonpath_exec.c:1442:54: error: declaration of 
'elem' shadows a previous local [-Werror=shadow=compatible-local]

There is a typo in the commit message: "Implement jasonpath"

Any reason this patch is separate from 0002?  Isn't number() and 
decimal() pretty similar?

You could also update src/backend/catalog/sql_features.txt in each patch 
(features T865 through T878).