Andrew Dunstan <andrew@dunslane.net> writes:
> On 08/29/2015 08:47 AM, Shulgin, Oleksandr wrote:
>> Given there were no loud complaints about this, the current behavior
>> is appropriate for most users, the rest can still work around using
>> coalesce(to_json(...), json 'null').
> I don't think it's necessarily more correct. But I do agree that it's
> not a good idea to change the behaviour unless there is major
> unhappiness with it.
I'm not entirely convinced that JSON NULL and SQL NULL should be treated
as the same concept, so I would say that the current behavior is fine ---
at least when you think about it in isolation. However, haven't we
already bought into that equivalence in these examples?
regression=# select row_to_json(row(1,null,2)); row_to_json
---------------------------{"f1":1,"f2":null,"f3":2}
(1 row)
regression=# select array_to_json(array[1,null,2]);array_to_json
---------------[1,null,2]
(1 row)
or even in to_json itself:
regression=# select to_json(array[1,null,2]); to_json
------------[1,null,2]
(1 row)
The scalar case is definitely failing to be consistent with these.
Is consistency a sufficient reason to change it?
regards, tom lane
