Most SLRs, even entry-level ones, have a remote shutter release socket so you can shoot pictures without actually touching the camera body.The remote trigger is used often in long-exposure photography, where even a small amount of vibration can intr
--行级触发器 create or replace trigger insert_person after insert on person for each row begin insert into person2 values(:new.id,:new.name,:new.password); end; create or replace trigger update_person after update on person for each row begin update pers
本文介绍了oracle触发器的概念和类型,create or replace trigger bj_customer before update on customer for each row begin update order set cu_no=:new.cu_no， cu_name=:new.cu_name， cu_address=:new.cu_addess， where cu_no=:old.cu_
