1、编写一个过程
暂时在想
2、SELECT lpad(empno,' ',LEVEL*length(empno))
FROM emp
CONNECT BY PRIOR empno = mgr;
3、
create trigger emp_tri
before insert or update on emp
for each row
declare
num number;
begin
select sum(Sal) into num from emp where deptno=:new.deptno;
if num+:new.sal>20000 then
raise_application_error(-20000,'超出预算');
end if;
end;
/
以是触发报错,可以使用如下:
create view v_emp as select * from emp;
/
create trigger v_emp_tri
instead of insert or update v_emp
for each row
declare
num number;
begin
select sum(sal) into num from emp where deptno=:new.deptno;
if num+:new.sal>20000 then
raise_application_error(-20000,'超出预算');
end if;
end;
/
哪以后就直接对v_emp作插入与更新.