On Mar 13, 2013, at 10:59 AM, Andrew Dunstan <andrew@dunslane.net> wrote:
>> And my first cut at it won’t descend into sub-objects.
>
>
> The you wouldn't be doing it right. The whole thing about a recursive descent parser is that it's, well, recursive.
Right, but it would serve my immediate needs. I have a column that just stores key/value pairs with no nesting. So I
knowI can write something like this and have it be good enough:
create or replace function json_smash( json ) RETURNS JSON language SQL STRICT IMMUTABLE AS $$ SELECT
format('{%s}',array_to_string(ARRAY( SELECT format('%s: %s', to_json(key), value) FROM (
SELECT key, value, row_number() OVER ( partition by key order by rnum desc
) AS rnum FROM ( SELECT key, value, row_number() OVER (
partition by key ) AS rnum FROM json_each($1)
) a ) b WHERE rnum = 1 ), ','))::json; $$;
And do you really want to see that unloosed on the world? :-P (Yes, I know there is no guarantee on the order of rows
returnedby json_each()).
Best,
David