PHP develops chat record export and archiving of real-time chat function

CREATE TABLE chat_messages (
    id INT AUTO_INCREMENT PRIMARY KEY,
    sender INT NOT NULL,
    receiver INT NOT NULL,
    message TEXT NOT NULL,
    timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

<?php

// 假设我们通过GET请求传递了发送者ID、接收者ID和消息内容
$senderId = $_GET['sender_id'];
$receiverId = $_GET['receiver_id'];
$message = $_GET['message'];

// 连接数据库
$pdo = new PDO('mysql:host=localhost;dbname=your_database_name', 'your_username', 'your_password');

// 插入聊天记录到数据库
$query = $pdo->prepare("INSERT INTO chat_messages (sender, receiver, message) VALUES (?, ?, ?)");
$query->execute([$senderId, $receiverId, $message]);

// 关闭数据库连接
$pdo = null;

?>

<?php

// 假设我们通过GET请求传递了要导出的聊天记录的起始和结束时间
$startTime = $_GET['start_time'];
$endTime = $_GET['end_time'];

// 连接数据库
$pdo = new PDO('mysql:host=localhost;dbname=your_database_name', 'your_username', 'your_password');

// 检索特定时间范围内的聊天记录
$query = $pdo->prepare("SELECT * FROM chat_messages WHERE timestamp BETWEEN ? AND ?");
$query->execute([$startTime, $endTime]);
$chatRecords = $query->fetchAll(PDO::FETCH_ASSOC);

// 关闭数据库连接
$pdo = null;

// 将聊天记录保存为CSV文件
$filename = 'chat_records.csv';
$file = fopen($filename, 'w');

// 写入CSV文件头
$header = ['ID', 'Sender', 'Receiver', 'Message', 'Timestamp'];
fputcsv($file, $header);

// 写入聊天记录
foreach ($chatRecords as $record) {
    fputcsv($file, $record);
}

// 关闭文件
fclose($file);

// 提示下载文件
header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename="' . $filename . '"');
readfile($filename);

?>

<?php

// 连接数据库
$pdo = new PDO('mysql:host=localhost;dbname=your_database_name', 'your_username', 'your_password');

// 检索所有聊天记录
$query = $pdo->prepare("SELECT * FROM chat_messages");
$query->execute();
$chatRecords = $query->fetchAll(PDO::FETCH_ASSOC);

// 关闭数据库连接
$pdo = null;

// 输出聊天记录
foreach ($chatRecords as $record) {
    echo "Sender: " . $record['sender'] . "<br>";
    echo "Receiver: " . $record['receiver'] . "<br>";
    echo "Message: " . $record['message'] . "<br>";
    echo "Timestamp: " . $record['timestamp'] . "<br>";
    echo "<br>";
}

?>