Postgresql table with auto increment id , created_at, updated_at

user.sql

CREATE OR REPLACE FUNCTION trigger_set_timestamp()
RETURNS TRIGGER AS $$
BEGIN
  NEW.updated_at = NOW();
  RETURN NEW;
END;
$$ LANGUAGE plpgsql;

create table users (
   id SERIAL PRIMARY KEY NOT NULL,
   first_name TEXT NOT NULL,
   last_name TEXT NOT NULL,
   created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
   updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
)

CREATE TRIGGER set_timestamp
BEFORE UPDATE ON users
FOR EACH ROW
EXECUTE PROCEDURE trigger_set_timestamp();


INSERT INTO users (first_name,last_name) 
VALUES ( 'Jayan' , 'Jacob') RETURNING *

SELECT * FROM users

UPDATE users 
   SET last_name = 'JACOB' 
 WHERE id = 1 RETURNING *;

SELECT * FROM users