oracle触发器可以创建，但是teacher表上没有这个触发器

```create or replace
trigger update_sal 
before insert or update of sal,pos on teacher 
for each row 
when (new.pos='教授') 
begin 
if :new.sal<1000 then 
:new.sal:=1000; 
end if; 
end;

https://blog.csdn.net/DavieSmile/article/details/84586818