[PHP知识库]PHP 导出 大量数据 到CSV

为解决内存超出问题，修改PHP.ini limit_momery?不起做用? 可采用分页写写数据到文件内 代码下

header('Content-Description: File Transfer');
header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment; filename="'. $file .'"');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');

$columns = [
    'ID','报警','设备名称','设备类型','开始时间','结束时间','描述','处理方式','责任等级','处理结果'
];

$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

$total = Alarm::getTotal($payload);
$pageSize = 5000;
$pages = ceil($total / $pageSize);

for ($page = 1;$page <= $pages ;$page ++){
    $offset = ($page-1)*$pageSize;
    $payload['offset'] = $offset;
    $payload['limit'] = $pageSize;
    $list = Alarm::getList($payload);

    foreach ($list as $alarm){
        $row [] = $alarm['id'];
        mb_convert_variables('GBK', 'UTF-8', $row);
        fputcsv($fp, $row);
        unset($row);
    }

    if(ob_get_level()>0)
        ob_flush() ;

    flush();
}
exit();

这样下载的数据可以达到几十万条