我尝试从数据库创建excel文件下载功能。但是面临问题33554432字节用尽了

Question

我使用AWS服务器选择ubuntu并安装vestacp管理面板。我用的是Apache2和php版本7.0 ..... 我遇到问题创建excel文件下载。我更改了php.ini和.htaccess文件的内存限制，但没有解决此错误。请帮助你。 这是我用来创建excel文件下载的代码。

消息：允许的内存大小为33554432字节已用尽（尝试分配4096字节）

public function coupon(){
        ini_set('memory_limit','128M');

        $this->load->library('Classes/PHPExcel');

        $queryexport = "select * from tbl_coupons";
        $query = $this->m_export->executeDbQuery($queryexport); 

        // Instantiate a new PHPExcel object
        $objPHPExcel = new PHPExcel();
        $objPHPExcel->getProperties()->setTitle("export")->setDescription("none");

        $objPHPExcel->setActiveSheetIndex(0);

        // Field names in the first row
        $fields = $query->list_fields();
        $col = 0;
        foreach ($fields as $field)
        {
            if($field == 'update_time'){
                continue;
            }
        $objPHPExcel->getActiveSheet()->setCellValueByColumnAndRow($col, 1, stripslashes($field));
            $col++;
        }
        //pr($fields);die;
        // Fetching the table data
        $row = 2;
        foreach($query->result() as $data)
        {
            $col = 0;$id = 0;
            foreach ($fields as $field)
            {
                if($field == 'update_time'){
                continue;
            }
        if($field == 'id'){
                    $id = $data->$field;
                }
                if($field == 'categories'){
                    $storeCategories = getCouponCategories($id);
                    $arrCategoryIds = implode(',', $storeCategories);
                    $objPHPExcel->getActiveSheet()->setCellValueByColumnAndRow($col, $row, $arrCategoryIds);
                }else{
                    $objPHPExcel->getActiveSheet()->setCellValueByColumnAndRow($col, $row, stripslashes($data->$field));
                }
                $col++;
            }

            $row++;
        }

        $objPHPExcel->setActiveSheetIndex(0); 

        $objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');

        $filename = "couponexcel_" . date('Ymd') . ".xls";
        // Sending headers to force the user to download the file
        header('Content-Type: application/vnd.ms-excel');
        header('Content-Disposition: attachment;filename="'.$filename.'"');
        header('Cache-Control: max-age=0');

        $objWriter->save('php://output');
    }