[Postgres][jsonb_set][jsonb_insert] nested field

gistfile1.txt

INSERT - jsonb_insert
update my_table 
set my_column = jsonb_insert(my_column, '{field1, field2, newkey}', '"hello insert"')
where id = 1;
// SELECT result: {"field1": {"field2": {"newvalue": "hello insert"}}}

SET - jsonb_set
update my_table 
set my_column = jsonb_set(my_column, '{field1, field2}', '{"existingKey":"bye hello value"}')
where id = 1;
// SELECT result: {"field1": {"field2": {"existingKey": "bye hello value"}}}