create table log_trigger (num number(10), texte varchar2(100));
create SEQUENCE seq_cpt2 start with 1 increment by 1 ;
create or replace TRIGGER avantInsertion
before INSERT on categories
BEGIN
	--insert or update or delete on categories
  insert  into Log_trigger values (seq_cpt2.nextval, 'test trigger before');
end avantInsertion;

create or replace TRIGGER apresInsertion
after INSERT on categories
BEGIN
  insert  into Log_trigger values (seq_cpt2.nextval, 'test trigger after');
end apresInsertion;


--insertion dans la table categories
select * from categories;
select * from log_trigger;

insert into categories 
values (60,'valeur de la sequence :' || seq_cpt2.nextval);
ROLLBACK;