Re: remaining sql/json patches

jian he <jian(dot)universality(at)gmail(dot)com> writes:

> On Tue, Mar 5, 2024 at 12:38 PM Andy Fan <zhihuifan1213(at)163(dot)com> wrote:
>>
>>
>> In the commit message of 0001, we have:
>>
>> """
>> Both JSON_VALUE() and JSON_QUERY() functions have options for
>> handling EMPTY and ERROR conditions, which can be used to specify
>> the behavior when no values are matched and when an error occurs
>> during evaluation, respectively.
>>
>> All of these functions only operate on jsonb values. The workaround
>> for now is to cast the argument to jsonb.
>> """
>>
>> which is not clear for me why we introduce JSON_VALUE() function, is it
>> for handling EMPTY or ERROR conditions? I think the existing cast
>> workaround have a similar capacity?
>>
>
> I guess because it's in the standard.
> but I don't see individual sql standard Identifier, JSON_VALUE in
> sql_features.txt
> I do see JSON_QUERY.
> mysql also have JSON_VALUE, [1]
>
> EMPTY, ERROR: there is a standard Identifier: T825: SQL/JSON: ON EMPTY
> and ON ERROR clauses
>
> [1] https://dev.mysql.com/doc/refman/8.0/en/json-search-functions.html#function_json-value

Thank you for this informatoin!

--
Best Regards
Andy Fan