CREATE TABLE IF NOT EXISTS `users` (
 `id` int(10) NOT NULL AUTO_INCREMENT,
 `username` varchar(50) NOT NULL,
 `password` varchar(50) NOT NULL,
 `email` varchar(100) NOT NULL,
 `fullname` varchar(100) NOT NULL,
 PRIMARY KEY (`id`),
 UNIQUE KEY `username` (`username`),
 UNIQUE KEY `email` (`email`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

<?php
  class MTest extends CI_Model{
    public function __construct(){
      parent::__construct();
      $this->load->database();
    }
    //insert into data
    public function insert_users($arr){
      $this->db->insert('users',$arr);
    }
    //delete data
    public function delete_users($id){
      $this->db->where('id',$id);
      $this->db->delete('users');
    }
    //Alter data
    public function update_users($username,$arr){
      $this->db->where('username',$username);
      $this->db->update('users',$arr);
    }
    //select data
    public function select_users($id){
      $this->db->where('id',$id);
      $this->db->select('*');
      return $this->db->get('users');
      //注意如果你返回的是以下内容的话，他就是一个对象的结果集，这样当你返回controller中时，你就得转换；
//     return $query->result();
    }
  }
?>

<?php
/**
 * xxx.php
 * ==============================================
 * Copy right 2012-2015
 * ----------------------------------------------
 * This is not a free software, without any authorization is not allowed to use and spread.
 * ==============================================
 * @Author:YeXianMing
 * @Email:LangWaiShiGe@hotmail.com
 * @Version:zend studio10.6.2 php5.4.38 apache2.2
 */
  if(!defined('BASEPATH'))exit('No direct script access allowed');
  class Home extends CI_Controller{
    public function __construct(){
      parent::__construct();
    }
    //insert data
    public function insert(){
      $this->load->model('MTest','',TRUE);
      $arr=array('username'=>'yexianming1','password'=>'admin','email'=>'11504160314qq.com','fullname'=>'luotianyexianming');
      if(!($this->MTest->insert_users($arr))){
        echo "插入数据成功";
      }else{
        echo "插入数据失败";
      }
    }
    //update data
    public function update(){
      $this->load->model('MTest','',TRUE);
      $arr=array('username'=>'Helloworld22','password'=>'root','email'=>'895787704@qq.com','fullname'=>'luotianyecong');
      if(!($this->MTest->update_users('Helloworld',$arr))){
        echo "修改成功";
      }else{
        echo "修改失败";
      }
    }
    //delete data
    public function delete(){
      $this->load->model('MTest','',TRUE);
      $query=$this->MTest->delete_users(12);
      if(!$query){
        echo "删除成功";
      }else{
        echo "删除失败";
      }
    }
    //select data
    public function select(){
      $this->load->library('table');
      $this->load->model('MTest','',TRUE);
      $arr=$this->MTest->select_users(3);
      $userinformation=$this->table->generate($arr);
      $data['userinfor']=$userinformation;
      $this->load->view('template',$data);
    }
  }
?>

<?php echo $userinfor;?>

id username password email fullname
3 Helloworld22 root 1111111@qq.com luotianyecong