Bryn Llewellyn schrieb am 04.06.2022 um 03:41:
Am I missing a use case where an object with a key-value pair with a
JSON null value is meaningfully different from one where the key is
simply absent?
It seems the JSON specification doesn't actually define equality.
But the JSON patch RFC 6902[1] defines the equality of two objects
as:
objects: are considered equal if they contain the same number of
members, and if each member can be considered equal to a member in
the other object, by comparing their keys (as strings) and their
values (using this list of type-specific rules).
As {"x": 42, "y": null} and {"x": 42} do not contain the same number
of members, I think Postgres' behaviour is correct.
Thomas
[1] https://www.rfc-editor.org/rfc/rfc6902#section-4.6
