Update Postgresql table straight from a JSON object

Question

I use

select to_json(host) from host where id=3

to query data from my postgreSQL database the result is like:

{"id":3,"project_id":1,"name":"a","mac":"abc","info":"x"}

after altering the data in my application I want to update the table.

Is there a "json"-way to do this? Not doing a ordinary update like

update host set project_id=1, name='a', mac='abc',info='x' where id=1;

Answer 1

Use jsonb_populate_record in the update from clause

update host
set
    (project_id, name, mac, info) =
    (j.project_id, j.name, j.mac, j.info)
from jsonb_populate_record ( null::host,
    '{"id":1,"project_id":1,"name":"a","mac":"abc","info":"x"}'::jsonb
) j
where host.id = j.id