If this query for select all records where id = 11:
$this->db->select('title')->from('mytable')->where('id', $id)->limit(10, 20);
$query = $this->db->get();
then what is the query to select all records where id != 11 in CodeIgniter style?
Just add it to the column part of the where, so
$this->db->select('title')->from('mytable')->where('id !=', $id)->limit(10, 20);
$query = $this->db->get();
Btw, always check the codeigniter manual, it mentions it right with the where() documentation and it's one of the best documentations you are ever going to find.