PHP回显数据库中的表，并将其作为CSV文件下载

<?php
// 连接数据库
$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("连接数据库失败: " . $conn->connect_error);
}

// 查询数据库表
$sql = "SELECT * FROM 表名";
$result = $conn->query($sql);

// 将查询结果转换为CSV格式
$csvData = '';
if ($result->num_rows > 0) {
    while ($row = $result->fetch_assoc()) {
        $csvData .= implode(',', $row) . "\n";
    }
}

// 设置HTTP头信息
header('Content-Type: application/csv');
header('Content-Disposition: attachment; filename=table.csv');

// 输出CSV文件
$file = fopen('php://output', 'w');
fwrite($file, $csvData);
fclose($file);

// 关闭数据库连接
$conn->close();
?>