Triggers

create table autor(
id_autor int,
constraint pk_id_autor primary key(id_autor));

create table libro(
id_libro int,
id_autor int,
constraint pk_id_libro primary key(id_libro),
constraint fk_id_autor foreign key(id_autor) references autor);


ALTER TABLE libro
disable CONSTRAINT fk_id_autor;

insert into autor values(12);
insert into libro values(5,12);

delete from autor
where id_autor = 11;

select * from libro;
select * from autor;

TRIGGER

create or replace trigger miPrimerTrigger
after delete on autor
references old as libroViejo
for each row
begin
     delete from libro
     where id_autor = :libroviejo.id_autor;
    
end;

show err trigger miPrimerTrigger;

delete from autor
where id_autor = 11;