application/modelsPhoto_model.php

<?php
if (!defined('BASEPATH'))
    exit('No direct script access allowed');
/**
 * photo_model
 * @author zhangwenxin
 *
 */
class Photo_model extends CI_Model{
    private $table = 'photo';
    public function __construct()
    {
        parent::__construct();

    }
    /**
     * get one data
     * */
    public function getUserRow($userId = 0)
    {
        $this->db->where('id', $userId);
        $result = $this->db->get($this->table);
        return $result->row_array();
    }

    /**
     * get photo thumb
     * @param int $id
     * @return mixed
     */
    public function getThumb($id = 0){
        $this->db->where('photo_id', $id);
        $result = $this->db->get('photo_thumb');
        return $result->row_array();
    }
}