PHP는 엄청난 양의 데이터가 포함된 EXCEL 파일을 실시간으로 생성하고 다운로드합니다.

$fp = fopen('php://output', 'a');
fputs($fp, 'strings');
....
....
fclose($fp)

/**
     * 文章访问日志
     * 下载的日志文件通常很大, 所以先设置csv相关的Header头, 然后打开
     * PHP output流, 渐进式的往output流中写入数据, 写到一定量后将系统缓冲冲刷到响应中
     * 避免缓冲溢出
     */
    public function articleAccessLog($timeStart, $timeEnd)
    {
        set_time_limit(0);
        $columns = [
            '文章ID', '文章标题', ......
        ];
        $csvFileName = '用户日志' . $timeStart .'_'. $timeEnd . '.xlsx';
        //设置好告诉浏览器要下载excel文件的headers
        header('Content-Description: File Transfer');
        header('Content-Type: application/vnd.ms-excel');
        header('Content-Disposition: attachment; filename="'. $fileName .'"');
        header('Expires: 0');
        header('Cache-Control: must-revalidate');
        header('Pragma: public');
        $fp = fopen('php://output', 'a');//打开output流
        mb_convert_variables('GBK', 'UTF-8', $columns);
        fputcsv($fp, $columns);//将数据格式化为CSV格式并写入到output流中
        $accessNum = '1000000'//从数据库获取总量，假设是一百万
        $perSize = 1000;//每次查询的条数
        $pages   = ceil($accessNum / $perSize);
        $lastId  = 0;
        for($i = 1; $i <= $pages; $i++) {
            $accessLog = $logService->getArticleAccessLog($timeStart, $timeEnd, $lastId, $perSize);
            foreach($accessLog as $access) {
                $rowData = [
                    ......//每一行的数据
                ];
                mb_convert_variables(&#39;GBK&#39;, &#39;UTF-8&#39;, $rowData);
                fputcsv($fp, $rowData);
                $lastId = $access->id;
            }
            unset($accessLog);//释放变量的内存
            //刷新输出缓冲到浏览器
            ob_flush();
            flush();//必须同时使用 ob_flush() 和flush() 函数来刷新输出缓冲。
        }
        fclose($fp);
        exit();
    }

SELECT columns FROM `table_name` 
WHERE `created_at` >= 'time range start' 
AND `created_at` <= &#39;time range end&#39; 
AND  `id` < LastId 
ORDER BY `id` DESC 
LIMIT num