php -使用mysql下载文件

<?php
// 连接到MySQL数据库
$servername = "数据库服务器地址";
$username = "数据库用户名";
$password = "数据库密码";
$dbname = "数据库名";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 查询文件信息
$sql = "SELECT file_name, file_path FROM files WHERE id = 1"; // 假设文件id为1
$result = $conn->query($sql);
if ($result->num_rows > 0) {
    $row = $result->fetch_assoc();
    $file_name = $row["file_name"];
    $file_path = $row["file_path"];

    // 下载文件
    header("Content-Type: application/octet-stream");
    header("Content-Disposition: attachment; filename=" . $file_name);
    readfile($file_path);
} else {
    echo "文件不存在";
}

$conn->close();
?>