multiple database in codeigniter

I'm trying to implement multiple database in CI. My code Is here:

//database.php
$active_group = "default";
$active_record = TRUE;

$db['default']['hostname'] = "localhost";
$db['default']['username'] = "root";
$db['default']['password'] = "root";
$db['default']['database'] = "ravelex";
$db['default']['dbdriver'] = "mysql";
$db['default']['dbprefix'] = "rvx_";
$db['default']['pconnect'] = TRUE;
$db['defau开发者_如何转开发lt']['db_debug'] = TRUE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = "";
$db['default']['char_set'] = "utf8";
$db['default']['dbcollat'] = "utf8_general_ci";

$db['smf']['hostname'] = "localhost";
$db['smf']['username'] = "root";
$db['smf']['password'] = "root";
$db['smf']['database'] = "smf";
$db['smf']['dbdriver'] = "mysql";
$db['smf']['dbprefix'] = "smf_";
$db['smf']['pconnect'] = TRUE;
$db['smf']['db_debug'] = TRUE;
$db['smf']['cache_on'] = FALSE;
$db['smf']['cachedir'] = "";
$db['smf']['char_set'] = "utf8";
$db['smf']['dbcollat'] = "utf8_general_ci";

The model is

//user_model.php
class user_model extends Model {
    private $ravelex_db;
    function user_model() {
        parent::Model();
        $this->ravelex_db = $this->load->database('default', TRUE);
    }

    function find_all() {
        print_r($this->ravelex_db);
        $q = $this->ravelex_db->get('users');
        return $q->result();
    }
}

//smf_user_model.php
class smf_user_model extends Model {
    private $smf_db;

    function smf_user_model() {
        parent::Model();
        $this->smf_db = $this->load->database('smf', TRUE);
    }

    function find_all() {
        $q = $this->smf_db->get('members');
        return $q->result();
    }
}

Controller tester

    class mutipledb extends Controller {

    function mutipledb() {
        parent::Controller();
        $this->load->database();
        $this->load->model('user_model');
        $this->load->model('smf_user_model');
    }

    function index() {
        print_r($this->user_model->find_all());
        print_r($this->smf_user_model->find_all());
    }
}

There are some error, The first database uses the second database name. But it still use it's prefix.

The error is

A Database Error Occurred
Error Number: 1146
Table 'smf.rvx_users' doesn't exist
SELECT * FROM (`rvx_users`)

---

at controller tester file, please comment the line: $this->load->database();

will solve the problem

---

There is a bug in codeigniter. Inserting one line into a class will fix the whole thing. Here is the original source: http://koorb.wordpress.com/2007/11/16/codeigniter-connect-to-multiple-databases/

Here is a copy just in case that site goes down.

The line number has changed. Here is the bug fix from codeigniter:

----- start bugfix -----

Description

all of the database calls go to the same database (last one initialized)

To fix the problem change the simple_query function in /system/database/DB_driver.php:

function simple_query($sql)
{
    if ( ! $this->conn_id)
    {
        $this->initialize();
    }

    $this->db_select(); //<-----------------  Added this line
    return $this->_execute($sql);
}

--- END BUGFIX ----

This completely fixes the problem, so you can do stuff like this in a model

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