public function getInnerJoin(){
              return $this->find('columns: a.id, a.denominacion, (p.costo + (p.costo * p.ganancia / 100)) AS precio',
				  'join: a LEFT JOIN articulos.precio p on(a.id = p.articulo_id)',
				  'conditions: not exists (select 1 from articulos.precio p2 where p2.articulo_id = a.id and p2.fecha_at > p.fecha_at);');
        }
	public function buscar(){
		return $this->find_all_by_sql("SELECT a.id, a.denominacion, (p.costo + (p.costo * p.ganancia / 100)) AS precio
    FROM articulos.articulo a LEFT JOIN articulos.precio p on(a.id =p.articulo_id)
   WHERE not exists (select 1 from articulos.precio p2 where p2.articulo_id = a.id and p2.fecha_at > p.fecha_at);");