ORACLE—plsql创建触发器语句

create or replace trigger TIB_T_EXAM
before insert on t_exam
for each row
declare
integrity_error  exception;
errno            integer;
errmsg           char(200);
dummy            integer;
found            boolean;
begin
--  Column ID uses sequence SEQ_T_EXAM
select SEQ_T_EXAM.NEXTVAL INTO :new.ID from dual;

--  Errors handling
exception
when integrity_error then
raise_application_error(errno, errmsg);

end TIB_T_EXAM;