CodeIgniter：使用数据库伪造测试数据库是否存在

Question

I'm using CodeIgniter 3.1.0 to develop an app. In order to improve its installation, I've written an Install_Controller, and an Install_Model. I'm using Database Forge class to manage the database. Thanks to it, I can create a DB, but I can't check before if it exists. Actually, my idea was to pass a query to dbforge, like "CREATE DATABASE IF NOT EXISTS mydatabase". I've search the doc but there wasn't any function that could meet my requirements. Where can I write such a query ?

Here is an excerpt from the former :

$this->load->model('Install_Model');
$this->Install_Model->launchInstall();

Here is the code of the latter :

class Install_Model extends CI_Model {

    public function __construct()   {

        parent::__construct();

            $this->load->dbforge();

    }

    public function index() {

        if ($this->dbforge->create_database('mydatabase')) 
        {
            echo "OK";
        }

        else {

            echo "Error somewhere";
        }

        $this->load->database('mydatabase');
    }

}

Answer 1

you can use this custom SQL query function within your installation script to create new database.

public function createDB($databse) {
    $strSQL = "CREATE DATABASE IF NOT EXISTS $databse";
    $query = $this->db->query($strSQL);
   if (!$query) {
      throw new Exception($this->db->_error_message(),
      $this->db->_error_number());
                return FALSE;
            } else {
                return TRUE;
            }

}