Switch dynamic database from other DB in Codeigniter

Question

mi file config.php is:

$active_group = \'default\';
$active_record = TRUE;

db master is unique DB

$db[\'master\'][\'hostname\']         


        

Answer 1

database.php

$active_group  = 'master';
$active_record = TRUE;

// SQL Server
$db['master']['hostname'] = "localhost";
$db['master']['username'] = "root"; 
$db['master']['password'] = ""; 
$db['master']['database'] = "admin_nb";
$db['master']['dbdriver'] = "mysqli"; 
$db['master']['dbprefix'] = ''; 
$db['master']['pconnect'] = FALSE; 
$db['master']['db_debug'] = TRUE; 
$db['master']['cache_on'] = FALSE; 
$db['master']['cachedir'] = ""; 
$db['master']['char_set'] = "utf8"; 
$db['master']['dbcollat'] = "utf8_general_ci";

trabajador.php

class Trabajador extends CI_Controller
{

    public function __construct()
    {
        parent::__construct();

        $this->load->driver('cache');
        $this->load->helper(array(
            'form',
            'url',
            'otros_helper',
            'fechas_helper',
            'imagen_helper'
        ));

        // Se le asigna a la informacion a la variable $user.
        $this->abbost_hotel = @$this->session->userdata(
            'sess_abbost_hotel_' . substr(base_url(), -8, 7)
        );

        $database_name = $this->abbost_hotel->nombre_bd; /*var session*/
        $config_app = array(
            'hostname' => 'localhost',
            'username' => 'root',
            'password' => '',
            'database' => $database_name,
            'dbdriver' => 'mysqli',
            'dbprefix' => '',
            'pconnect' => FALSE,
            'db_debug' => TRUE
        );

        $this->load->model('model_tareas');
        $result = Model_tareas::m_cargar_tareas_activas($config_app);
        var_dump($result);
    }

}

model_tareas.php

class Model_tareas extends CI_Model
{

    public function m_cargar_tareas_activas($group_name)
    {
        $server = $this->load->database($group_name);
        $estado = 1;
        $server->select("colum1,colum2");
        $server->from('tarea');
        $query = $server->get();
        return $query->result_array();
    }

}

Check the documentation of CodeIgniter in database section:
https://ellislab.com/codeigniter/user-guide/database/connecting.html

Manually Connecting to a Database

The first parameter of this function can optionally be used to specify a particular database group from your config file, or you can even submit connection values for a database that is not specified in your config file. Examples:

To choose a specific group from your config file you can do this:

    $this->load->database('group_name');

Where group_name is the name of the connection group from your config file.