create table note_book (
    old_job varchar(100),
    new_job varchar(100),
    set_job_time timestamp
);

CREATE OR REPLACE FUNCTION process_set_job() RETURNS TRIGGER AS $new_emp$
    BEGIN
        if(TG_OP = 'UPDATE') THEN
            INSERT INTO note_book(old_job, new_job, set_job_time)  VALUES(OLD.job, NEW.job, now());
        ELSIF (TG_OP = 'DELETE') THEN
            INSERT INTO note_book(old_job, new_job, set_job_time) VALUES(OlD.job, 'fired', now());
        ELSIF (TG_OP = 'INSERT') THEN
            INSERT INTO note_book(old_job, new_job, set_job_time) VALUES('accepted', NEW.job, now());
        END IF;
        RETURN NULL;
    END;
$new_emp$ LANGUAGE plpgsql;

CREATE TRIGGER chek_set_job
AFTER INSERT OR UPDATE OR DELETE ON new_emp
    FOR EACH ROW EXECUTE FUNCTION process_set_job();

DELETE from new_emp where empno = 0;

INSERT INTO new_Emp VALUES (0,'BRIAN MOORE','JUNIOR DEVELOPER',null,TO_DATE('2017-07-10', 'YYYY-MM-DD'),7040,null,78);