将数据从数据库导出到excel文件

Question

将数据从数据库导出到excel文件时出现问题。我正在使用CodeIgniter和库PHPExcel。

public function export(){
    $ambildata = $this->model_kelola->read(NULL,NULL,'market','result',NULL,NULL);
    if(count($ambildata )>0){
        $objPHPExcel = new PHPExcel();

        $objPHPExcel->getProperties()->setCreator("Administrator")->setTitle("Data Quotation Prices");
        $objset = $objPHPExcel->setActiveSheetIndex(0);
        $objget = $objPHPExcel->getActiveSheet();
        $objget->setTitle('Sample Sheet');
        $objget->getStyle("A1:C1")->applyFromArray(
            array(
                'fill' => array(
                    'type' => PHPExcel_Style_Fill::FILL_SOLID,
                    'color' => array('rgb' => '92d050')
                ),
                'font' => array(
                    'color' => array('rgb' => '000000')
                )
            )
        );

        $cols = array("A","B","C");
        $val = array("Market Series ","Market Coupon","Market Maturity");
        for ($a=0;$a<3; $a++) {
            $objset->setCellValue($cols[$a].'1', $val[$a]);
            $objPHPExcel->getActiveSheet()->getColumnDimension('A')->setWidth(25);
            $objPHPExcel->getActiveSheet()->getColumnDimension('B')->setWidth(25);
            $objPHPExcel->getActiveSheet()->getColumnDimension('C')->setWidth(25);
            $style = array(
                'alignment' => array(
                    'horizontal' => PHPExcel_Style_Alignment::VERTICAL_CENTER,
                )
            );
            $objPHPExcel->getActiveSheet()->getStyle($cols[$a].'1')->applyFromArray($style);
        }
        $baris  = 2;
        foreach ($ambildata as $frow){    
            $objset->setCellValue("A".$baris, $frow->market_series);
            $objset->setCellValue("B".$baris, $frow->market_coupon);                
            $objset->setCellValue("C".$baris, $frow->market_maturity);

            $objPHPExcel->getActiveSheet()->getStyle('C1:C'.$baris)->getNumberFormat()->setFormatCode('0');
            $baris++;
        }
        $objPHPExcel->getActiveSheet()->setTitle('Data Export');
        $objPHPExcel->setActiveSheetIndex(0);
        $filename = urlencode("Data".date("Y-m-d H:i:s").".xls");
        header('Content-Type: application/xlx');
        header('Content-Disposition: attachment;filename="'.$filename.'"');
        $objWriter = IOFactory::createWriter($objPHPExcel, 'Excel5');                
        $objWriter->save('php://output');
    }
    else{
        redirect('Excel');
    }
}

这是我的错误

当试试print_r（get_defined_vars（））时，生成如下消息：

你能告诉我哪里错了吗？