行触发器-big.data.analytics.with.spark

21.2、行触发器执行DML操作时，每作用一行就触发一次触发器。 Bofre行触发器例如：确保员工工资不能低于原有工资Create or replace trigger tr_emp_sal before update of sal on emp for each row begin if :new.sal<:old.sal then raise_application_error(-20010,'sal should not be less'); end if; end; / after行触发器例如：统计员工工资变化Create table audit_emp_change( Name varchar2(10), Oldsal number(6,2), Newsal number(6,2), Time date); Create or replace trigger tr_sal after update of sal on emp for each row declare v_temp int;