Active Record Challenge

[eluser]CARP[/eluser]
Hi guys
Can any1 help me to convert this long SQL into codeIgniter's ActiveRecord?
It will be a great reference for my further CI fun coding

Code:

SELECT
  IZQ.id AS idsubrubro,
  IZQ.nombre AS subrubro,
  DER.nombre AS rubropadre
FROM
  sis_rubro DER
  LEFT OUTER JOIN sis_rubro IZQ ON (IZQ.fk_rubro = DER.id)
WHERE
  IZQ.fk_rubro IS NOT NULL AND
  IZQ.id NOT IN (SELECT sis_proveedor_rubro.fk_rubro FROM sis_proveedor_rubro WHERE fk_proveedor = $idProveedor)
ORDER BY
  DER.nombre,
  IZQ.nombre

Thanks...

[eluser]Armchair Samurai[/eluser]

Code:

$idProveedor = $this->db->escape($idProveedor);

$this->db->select('IZQ.id idsubrubro, IZQ.nombre subrubro, DER.nombre rubropadre');
$this->db->join('sis_rubro IZQ', 'IZQ.fk_rubro = DER.id', 'left outer');
$this->db->where('IZQ.fk_rubro IS NOT NULL', NULL, FALSE);
$this->db->where("IZQ.id NOT IN (SELECT sis_proveedor_rubro.fk_rubro FROM sis_proveedor_rubre WHERE fk_proveedor = $idProveedor)", NULL, FALSE);
$this->db->order_by('DER.nombre', 'asc');
$this->db->order_by('IZQ.nombre', 'asc');

$query = $this->db->get('sis_rubro DER');