短网址 php源码

<?php
// 数据库连接
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "short_url_db";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 生成短网址
function generateShortUrl($url) {
    global $conn;
    $hash = hash('md5', $url);
    $shortUrl = substr($hash, 0, 6);
    
    // 检查短网址是否已存在
    $sql = "SELECT * FROM short_urls WHERE short_url = '$shortUrl'";
    $result = $conn->query($sql);
    
    if ($result->num_rows > 0) {
        // 如果已存在，重新生成
        return generateShortUrl($url);
    } else {
        // 插入数据库
        $sql = "INSERT INTO short_urls (long_url, short_url) VALUES ('$url', '$shortUrl')";
        $conn->query($sql);
        return $shortUrl;
    }
}

// 获取长网址
function getLongUrl($shortUrl) {
    global $conn;
    $sql = "SELECT long_url FROM short_urls WHERE short_url = '$shortUrl'";
    $result = $conn->query($sql);
    
    if ($result->num_rows > 0) {
        $row = $result->fetch_assoc();
        return $row["long_url"];
    } else {
        return "短网址不存在";
    }
}

// 示例
$longUrl = "https://www.example.com/very/long/url/that/needs/to/be/shortened";
$shortUrl = generateShortUrl($longUrl);
echo "长网址: " . $longUrl . "\n";
echo "短网址: " . $shortUrl . "\n";

$retrievedLongUrl = getLongUrl($shortUrl);
echo "还原的长网址: " . $retrievedLongUrl . "\n";

$conn->close();
?>