提示Warning: Trigger created with compilation errors？请问如何解决
create or replace trigger c2
2 before update
3 on emp1
4 for each row
5 begin
6 if :new.sal < :old.sal then
7 raise_application_error(-20002,'||:new.sal||' '||:old.sal||);
8 end if;
9 end;
10 /
Warning: Trigger created with compilation errors
