> On 04.06.2024, at 07:00, jian he <jian.universal...@gmail.com> wrote:
>
> On Tue, May 28, 2024 at 5:29 PM Markus Winand <markus.win...@winand.at> wrote:
>
>> 2. EMPTY [ARRAY|OBJECT] ON ERROR implies ERROR ON EMPTY
>>
>> 17beta1=# SELECT JSON_QUERY('[]', '$[*]' EMPTY ARRAY ON ERROR) a;
>> a
>> ----
>> []
>> (1 row)
>>
>> As NULL ON EMPTY is implied, it should give the same result as
>> explicitly adding NULL ON EMPTY:
>>
>
> I vaguely remember, we stumbled on ON ERROR, ON EMPTY several times.
> i don't have a standard,
In my understanding of the standard is that there is no distinction
between an explicit and implicit ON EMPTY clause.
E.g. clause 6.35 (json_query) Syntax Rule 4:
• If <JSON query empty behavior> is not specified, then NULL ON EMPTY is
implicit.
General Rule 5ai then covers the NULL ON EMPTY case:
• i) If the length of SEQ2 is 0 (zero) and ONEMPTY is NULL, then
let JV be the null value.
Neither of these make the ON EMPTY handling dependent on the presence of ON
ERROR.
-markus
