CREATE or replace TRIGGER PersonCheckAge
after delete ON Autor
for each row
begin
delete from Libro
where Libro.idautor =:old.idautor;
end

create table autor(
idautor number )
create table libro(
idlibro number ,
idautor number )
insert into libro values(1,1)

drop table autor
drop table libro
delete from autor where idautor = 1
select * from libro
select * from autor