Oracle trigger example change timestamp

create or replace trigger SYNC_ 表名_UPDATETIME_TRIGGER
before update on 表名
for each row
begin
select (SELECT (SYSDATE - TO_DATE(‘1970-1-1 8’, ‘YYYY-MM-DD HH24’)) * 86400000 + TO_NUMBER(TO_CHAR(SYSTIMESTAMP(3), ‘FF’)) AS MILLIONS FROM DUAL) into :NEW.UPDATETIME from dual ;
end;