CodeIgniter DB update

// Load the database library
$this->load->database();

// Set the data to be updated
$data = array(
  'column1' => 'value1',
  'column2' => 'value2',
  'column3' => 'value3'
);

// Set the conditions for the update
$this->db->where('id', $id);

// Perform the update
$this->db->update('table_name', $data);