In SQL JSON_TABLE, add an option on timestamp columns to take into account or not the timezone offset

In the SQL function JSON_TABLE, when a timestamp value indicated with a time zone offset (e.g.: "yyyy-mm-ddThh:mm:ss.nnnnnn<+/-Offset>") is retrieved to produce a timestamp column, the resulting value is always an UTC value (by adding or subtracting the indicated time zone offset), not a local value (without taking the offset into account).

However, it's often the case that you don't want to transform the local value of a timestamp into a UTC value. For example, web services implemented in LWI automatically convert the value of a timestamp parameter into a value with the time zone offset. So if you expose a web service in LWI and consume it in a SQLRPGLE, the value retrieved will be different from the one in the database if you're not in the UTC time zone.

As with other databases, it would be interesting to have an option on the timestamp column to indicate whether the time zone offset should be taken into account or not:

select * from json_table('{"root" : {"ts1" : "2023-05-31T12:21:57.123456+02:00"}}', 'lax $.root[*]' columns(ts1 timestamp TIMEZONE|NOTIMEZONE PATH 'lax $.ts1'));

Another solution would be to have another type of timestamp column to indicate whether the resulting timestamp should be produced taking into account the time zone offset or not:

select * from json_table('{"root" : {"ts1" : "2023-05-31T12:21:57.123456+02:00"}}', 'lax $.root[*]' columns(ts1 timestamp|timestamp_notimezone PATH 'lax $.ts1'));