Re: Selecting a JSON object of arrays from a PostgreSQL table

Also got this nice suggestion at https://stackoverflow.com/q/48050127/165071
-

SELECT COALESCE(
json_object_agg(
gid, array_to_json(y)
), '{}'::json)
FROM (
SELECT gid,
array_agg(
json_build_object(
'uid', uid,
'created', EXTRACT(EPOCH FROM created)::int,
'msg', msg)
) AS y
FROM chat /* WHERE gid = 0 */
GROUP BY gid
) x;