codeigniter update

$this->db->select('*')->from('my_table')
        ->group_start()
                ->where('a', 'a')
                ->or_group_start()
                        ->where('b', 'b')
                        ->where('c', 'c')
                ->group_end()
        ->group_end()
        ->where('d', 'd')
->get();

// Generates:
// SELECT * FROM (`my_table`) WHERE ( `a` = 'a' OR ( `b` = 'b' AND `c` = 'c' ) ) AND `d` = 'd'
$data = [
        'title' => $title,
        'name'  => $name,
        'date'  => $date
];

$builder->where('id', $id);
$builder->update($data);
// Produces:
//
//      UPDATE mytable
//      SET title = '{$title}', name = '{$name}', date = '{$date}'
//      WHERE id = $id
$table = "my_table";
$id = 1;
$update = ["status"=>"working"];
//Edit just above /\ if you don't need extra "where" clause
$query = $this->db->select()
            ->from($table)
            ->where('id', $id)
            ->get_compiled_select();
$data = $this->db->query("$query FOR UPDATE")->row_array();
$this->db->where('id', $data['id'])->update($table,$update);$data = array(
        'title' => $title,
        'name' => $name,
        'date' => $date
);

$this->db->where('id', $id);
$this->db->update('mytable', $data);
// Produces:
//
//      UPDATE mytable
//      SET title = '{$title}', name = '{$name}', date = '{$date}'
//      WHERE id = $id
$data = array(
        'title' => $title,
        'name' => $name,
        'date' => $date
);

$this->db->where('id', $id);
$this->db->update('mytable', $data);$this->db->select('ae_users.employee_id, ae_users.emp_name, ae_users.emp_name2, ae_users.emp_name3');
		$this->db->from('ae_users');                
		$this->db->where_in('ae_users.employee_id',$employee_ids);
                $this->db->_protect_identifiers = FALSE; // stop CI adding backticks
                $order = sprintf('FIELD(ae_users.employee_id, %s)', implode(', ', $employee_ids));
                $this->db->order_by($order);
                $this->db->_protect_identifiers = TRUE; 
		$query =$this->db->get();
               // echo '<pre>'; print_r($this->db->last_query());exit;
		if ($query->num_rows()) {
			return $query->result_array();
		} else {
			return 0;
		}