[eluser]Developer13[/eluser]
Couple of ways you could achieve this.
1 - Using get_where() and order_by():
$this->db->order_by('date DESC');
$query = $this->db->get_where('table', array('this' => $that));
2 - Using plain old get() and order_by() with where():
$this->db->order_by('date DESC');
$this->db->where('this', $that);
$query = $this->db->get('table');