public function execute()
    {
        try {
            $opts = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);
            $pdo  = new PDO('mysql:host=' . $this->host, $this->user, $this->pass, $opts);

            foreach ($this->queries as $query) {
                if (!is_array($query)) {
                    // Simple query
                    $pdo->query($this->phpci->interpolate($query));
                } elseif (isset($query['import'])) {
                    // SQL file execution
                    $this->executeFile($query['import']);
                } else {
                    throw new \Exception(Lang::get('invalid_command'));
                }
            }
        } catch (\Exception $ex) {
            $this->phpci->logFailure($ex->getMessage());
            return false;
        }
        return true;
    }