drop table t;
create table t(nom varchar2(10) primary key, age integer);
insert into t values('toto', 19);
insert into t values('titi', 21);
insert into t values('tutu', 24);
commit;

create or replace procedure rajeunit(n t.nom%type) is
begin
  update t set age = age - 1 where nom = n;
end;
/

create or replace function f return integer is
  n integer;
begin
  select count(*) into n from t;
  return n;
end;
/