Inserting NULL wherever possible on Postgres

UUID

To insert null UUIDs, activate the extension

create extension if not exists "uuid-ossp";

then use the function uuid_nil().

JSONB

To insert null JSONB, use the to_jsonb function:

UPDATE
  table_name
SET
  my_jsonb_column = to_jsonb(null)
WHERE
  id = 1;

-- or

UPDATE
  table_name
SET
  my_jsonb_column = 'null'::jsonb
WHERE
  id = '1';

Fair warning: JSONB null is different from SQL null.

SELECT
  pg_typeof(NULL) AS sql_null_type,
  pg_typeof('null'::jsonb) AS jsonb_null_type;

-- "sql_null_type"	"jsonb_null_type"
-- "unknown"	"jsonb"