PHP + Ajax处理大数据查询并导出Excel

<input type="button" value="确定导出" onclick="export()">
<a style="display: none" id="export_success" href="/uploads/excel.zip">导出成功，点击下载Excel</a>

function export(){
if(!confirm('导出时间较长，请耐心等待，导出成功前请勿刷新页面！是否继续？')){
return false;
} ajaxGetExportData(); var res = ;
$.ajax({
type: "GET",
async: false,
url: "/download_zip.php",
success:function(data){
res = data;
}
}); if(res == ){
alert('导出失败');
}else{
$("#export_success").show();
} }
function ajaxGetExportData(page){
var res = ;
$.ajax({
type: "GET",
async: false,
url: "/export.php?page="+page,
success:function(data){
res = data;
}
}); if(res == ){
page++;
ajaxGetExportData(page);
}
return true;
}

$page = $_GET['page'];if($page <= ){
$file_path = 'uploads/excel';
if (!file_exists($file_path)) {
@mkdir($file_path,,true);
}
$file_name = $file_path . '/' . $page . '.txt';
file_put_contents($file_name,''); echo ;
}else{
echo ;
}

$file_path = BASEPATH . '../uploads/excel';
$zip_name = BASEPATH . '../uploads/excel.zip';
@unlink($zip_name); // 加载zip类
$this->load->library('MakeZip');
$res = new MakeZip($file_path,$zip_name);
if($res){
echo ;
}else{
echo ;
} exit;