基于PHP的实时聊天系统的消息阅后即焚和阅后删除

CREATE TABLE messages (
    id INT PRIMARY KEY AUTO_INCREMENT,
    sender_id INT,
    receiver_id INT,
    content TEXT,
    create_time DATETIME,
    delete_time DATETIME
);

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");
if (mysqli_connect_errno()) {
    echo "数据库连接失败：" . mysqli_connect_error();
    die();
}

// 获取发送者ID和接收者ID
$senderId = $_POST['sender_id'];
$receiverId = $_POST['receiver_id'];

// 获取消息内容
$content = $_POST['content'];

// 获取当前时间
$createTime = date("Y-m-d H:i:s");

// 设置消息的删除时间为30分钟后
$deleteTime = date("Y-m-d H:i:s", strtotime("+30 minutes"));

// 插入消息到数据库
$sql = "INSERT INTO messages (sender_id, receiver_id, content, create_time, delete_time)
        VALUES ('$senderId', '$receiverId', '$content', '$createTime', '$deleteTime')";
mysqli_query($conn, $sql);

// 关闭数据库连接
mysqli_close($conn);

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");
if (mysqli_connect_errno()) {
    echo "数据库连接失败：" . mysqli_connect_error();
    die();
}

// 获取消息ID
$messageId = $_GET['message_id'];

// 获取当前时间
$currentTime = date("Y-m-d H:i:s");

// 查询消息的删除时间
$sql = "SELECT delete_time FROM messages WHERE id = $messageId";
$result = mysqli_query($conn, $sql);
$row = mysqli_fetch_assoc($result);
$deleteTime = $row['delete_time'];

// 检查当前时间是否超过了删除时间
if ($currentTime > $deleteTime) {
    // 超过了删除时间，删除消息
    $sql = "DELETE FROM messages WHERE id = $messageId";
    mysqli_query($conn, $sql);
} else {
    // 未超过删除时间，显示消息内容
    $sql = "SELECT content FROM messages WHERE id = $messageId";
    $result = mysqli_query($conn, $sql);
    $row = mysqli_fetch_assoc($result);
    echo $row['content'];
}

// 关闭数据库连接
mysqli_close($conn);