SELECT name
FROM
(SELECT (a->'component_id')::text::int as id FROM machines m, json_array_elements(m.reminders::json) as a) as component_id
JOIN components c ON c.id = component_id.id

SELECT
    r.machine_id,
    json_build_array(
        json_build_object('full', r.full),
        json_build_object('treshold', r.treshold),
        json_build_object('remainder', r.remainder),
        json_build_object('component_id', r.component_id),
        json_build_object('component_name', c.name),
        json_build_object('component_measure', c.measure)
    )::jsonb
FROM
    (SELECT m.id as machine_id, (a->'component_id')::text::int as component_id,
     (a->'full')::text::double precision as full,
     (a->'treshold')::text::double precision as treshold,
     (a->'remainder')::text::double precision as remainder
     FROM machines m, json_array_elements(m.reminders::json) as a) as r
JOIN components c ON c.id = r.component_id

SELECT
    r.machine_id,
    json_agg(
        json_build_object('full', r.full,
        'treshold', r.treshold,
        'remainder', r.remainder,
        'component_id', r.component_id,
        'component_name', c.name,
        'component_measure', c.measure) )
FROM
    (SELECT m.id as machine_id, (a->'component_id')::text::int as component_id,
     (a->'full')::text::double precision as full,
     (a->'treshold')::text::double precision as treshold,
     (a->'remainder')::text::double precision as remainder
     FROM machines m, json_array_elements(m.reminders::json) as a) as r
JOIN components c ON c.id = r.component_id
GROUP BY machine_id