將資料庫連線資訊、查詢條件、標題資訊替換為真實資料即可使用。

<?php
set_time_limit(0);
ini_set('memory_limit', '128M');
 
$fileName = date('YmdHis', time());
header('Content-Encoding: UTF-8');
header("Content-type:application/vnd.ms-excel;charset=UTF-8");
header('Content-Disposition: attachment;filename="' . $fileName
 
 . '.csv"');
 
 
//開啟php標準輸出流
//以寫入追加的方式開啟
$fp = fopen('php://output', 'a');

//連線資料庫
$dbhost = '127.0.0.1';
$dbuser = 'root';
$dbpwd = '';
$con = mysqli_connect($dbhost, $dbuser, $dbpwd);
if (mysqli_connect_errno()) {
   die('connect error');
}
//選擇資料庫
$database = 'test';
mysqli_select_db($con
 
, $database);
//設定編碼
mysqli_query($con, "set names UTF8");

 
//我們試著用fputcsv從資料庫中匯出1百萬的資料
//我們每次取1萬條資料，分100步來執行
//如果線上環境無法支援一次性讀取1萬條資料，可把$nums調小，$step相應增大。
$step = 100;
$nums = 10000;
$where = ""; //篩選條件
 
//設定標題
$title = array('ID','姓名‘,'年齡','性別');
foreach($title as $key => $item) {
    $title[$key] =iconv("UTF-8", "GBK", $item);
}
//將標題寫到標準輸出中
fputcsv($fp, $title);

for($s = 1; $s <= $step; $s++) {
    $start = ($s - 1) * $nums;
    $result = mysqli_query($con,"SELECT * FROM `test` ".$where." ORDER BY `id` LIMIT {$start},{$nums}");
    if($result) {
        while($row = mysqli_fetch_assoc($result)) {
            foreach($row as $key => $item) {
                //這裡必須轉碼，不然會亂碼
                $row[$key] = iconv("UTF-8", "GBK", $item);
            }
            fputcsv($fp, $row);
        }
        mysqli_free_result($result); //釋放結果集資源

        //每1萬條資料就重新整理緩衝區
        ob_flush();
        flush();
    }
}
//斷開連線
mysqli_close($con);