php 抽奖活动

<?php
function random_draw($participants) {
    $winner = $participants[array_rand($participants)];
    return $winner;
}

$participants = ['Alice', 'Bob', 'Charlie', 'David'];
$winner = random_draw($participants);
echo "Winner: " . $winner;
?>

<?php
// 假设有一个数据库表 winners 存储中奖者信息
$db = new PDO('mysql:host=localhost;dbname=lottery', 'username', 'password');

function draw_lottery($user_id) {
    $db->beginTransaction();
    try {
        // 检查用户是否已经中奖
        $stmt = $db->prepare("SELECT * FROM winners WHERE user_id = ?");
        $stmt->execute([$user_id]);
        if ($stmt->fetch()) {
            throw new Exception("User already won.");
        }

        // 插入中奖记录
        $stmt = $db->prepare("INSERT INTO winners (user_id) VALUES (?)");
        $stmt->execute([$user_id]);

        $db->commit();
        return true;
    } catch (Exception $e) {
        $db->rollBack();
        return false;
    }
}

$user_id = 123;
if (draw_lottery($user_id)) {
    echo "Congratulations! You won!";
} else {
    echo "Sorry, you didn't win this time.";
}
?>