我有两个具有相同结构和相同数据的emp表。copy_emp我希望如果发生任何变化都emp应该反映在copy_emp. 因此我创建了一个触发器，如下所示。
create or replace trigger t
after
insert or
update of empno or
delete
on emp
for each row
begin
case
when inserting then
insert into copy_emp(empno,ename,sal) values (:NEW.empno,:NEW.ename,:NEW.sal);
when updating then
if updating('empno') then
update copy_emp set copy_emp.empno=:new.empno where copy_emp.empno=:old.empno;
elsif updating('ename') then
update copy_emp set copy_emp.ename=:new.ename where copy_emp.ename=:old.ename;
elsif updating('sal') then
update copy_emp set copy_emp.sal=:new.sal where copy_emp.sal=:old.sal;
end if;
when deleting then
delete from copy_emp where empno = :old.empno; …