codeigniter 主从数据库

1. 在config/database.php 里面配置多一个数据库源，default为默认的可以是localhost也可以是IP，writedb为可读写的数据库，由于写的为主从互备的需要用IP远程调用，本人配置为：

   $active_group = 'default';

   $active_record = TRUE;

   $db['default']['hostname'] = 'localhost';

   $db['default']['username'] = 'default_username';

   $db['default']['password'] = 'default_password';

   $db['default']['database'] = 'default_dbname';

   $db['default']['dbdriver'] = 'mysql';

   $db['default']['dbprefix'] = '';

   $db['default']['pconnect'] = TRUE;

   $db['default']['db_debug'] = FALSE;

   $db['default']['cache_on'] = FALSE;

   $db['default']['cachedir'] = '';

   $db['default']['char_set'] = 'utf8';

   $db['default']['dbcollat'] = 'utf8_general_ci';

   $db['default']['swap_pre'] = '';

   $db['default']['autoinit'] = TRUE;

   $db['default']['stricton'] = FALSE;

   $db['writedb']['hostname'] = '202.187.194.160';

   $db['writedb']['username'] = 'writedb_name';

   $db['writedb']['password'] = 'writedb_password';

   $db['writedb']['database'] = 'writedb_db';

   $db['writedb']['dbdriver'] = 'mysql';

   $db['writedb']['dbprefix'] = '';

   $db['writedb']['pconnect'] = TRUE;

   $db['writedb']['db_debug'] = TRUE;

   $db['writedb']['cache_on'] = FALSE;

   $db['writedb']['cachedir'] = '';

   $db['writedb']['char_set'] = 'utf8';

   $db['writedb']['char_names'] = 'utf8';

   $db['writedb']['dbcollat'] = 'utf8_general_ci';

   $db['writedb']['swap_pre'] = '';

   $db['writedb']['autoinit'] = TRUE;

   $db['writedb']['stricton'] = FALSE;

2. M(Model)需要用到的Model配置两个数据源进来，只需要读的配置一个就可以了，当然如果是只写的也可以单独配置写的一个。

   本人一个问题反馈的实例feedbackmodel.php：

   <?php

   class Feedbackmodel extends CI_Model {

   function __construct() {

   parent::__construct ();

   $this->db = $this->load->database ('default',true);

   $this->writedb = $this->load->database ('writedb',true);

   }

   public function add($data)

   {

   $this->writedb->insert('feedback',$data);

   if($this->writedb->affected_rows() == 1){

   return true;

   }

   return false ;

   }

   }

   ?>

3. 3

   C(Controller)控制器的调用跟普通的一样，只要引入Model就可以了，本人实例：

   <?php 

   class Feedback extends CI_Controller {

   function __construct(){

   parent::__construct();

   }

   function index(){  

     $this->load->model('feedbackmodel');  

   $this->load->helper('url'); 

   $data['name'] = "feedback";

   $this->load->view('feedbackview',$data);

   }

   }

   ?>