public function actionImport() {
        $file = $_FILES['excel']['tmp_name'];

        try {
            Yii::import('ext.PHPExcel.XPHPExcel');
            $objPHPExcel= XPHPExcel::createPHPExcel();
            $load = PHPExcel_IOFactory::load($file);
            $sheets = $load->getActiveSheet()->toArray(null,true,true,true);

            $i = 1;
            $connection = Yii::app()->db;
            foreach ($sheets as $data) {
                $prodi = prodi::model()->findBySql("SELECT id FROM prodi WHERE nama LIKE '".$data['E']."%'");

                if ($i > 4) {
                    if(!empty($data['C'])) {
                        $sql = 'INSERT INTO mahasiswa SET';
                        $sql .= ' nim = "'.$data['C'].'",';
                        $sql .= ' nama = "'.$data['D'].'",';
                        $sql .= ' id_prodi = "'.$prodi->id.'";';

                        $retval = $connection->createCommand($sql)->execute();
                    }
                }
            $i++;
            }

        if($retval > 0) {
            Yii::app()->user->setFlash('success', "Data Mahasiswa berhasil di tambah.");
            $this->redirect(array("mahasiswa/index"));
        } else {
            Yii::app()->user->setFlash('info', "Tidak ada perubahan.");
            $this->redirect(array("mahasiswa/index"));
        }

        } catch (Exception $e) {
            Yii::app()->user->setFlash('error', "Terjadi kesalahan. Silakan coba kembali. Karena ".$e."");
            $this->redirect(array("mahasiswa/index"));
        }
    }