--create or replace trigger起至end ，一套语法结构，创建一个触发器(create or replace触发下面的代码)
create or replace trigger tr_update_employee_salary
instead of update

--触发器以来对象
on vw_employee_salary

begin

--声明变量totalMonth
declare totalMonth number;
begin

--给变量赋值
select count(distinct(month)) into totalMonth from t_salary where employee_id=:old.employee_id;

--更新到另外一张表
update t_salary set salary + (:new.total-:old.total)/totalMonth where employee_id=:old.employee_id;
end;
end;

------解决方案--------------------
--创建一个触发器名字为tr_update_employee_salary,  create or replace trigger是固定创建触发器的语句
create or replace trigger tr_update_employee_salary 
instead of update      --这句是有更新的时候就会触发
on vw_employee_salary     ]--这句是在vw_employee_salary这个对象进行触发


begin                    --开始执行的语句         


declare totalMonth number;        --声明变量为totalMonth number
begin                       --开始执行的语句
--给变量赋值
select count(distinct(month)) into totalMonth from t_salary where employee_id=:old.employee_id;

--更新到另外一张表
update t_salary set salary + (:new.total-:old.total)/totalMonth where employee_id=:old.employee_id;
end;
end;

[/Quote]