php mysql在线聊天系统源代码

CREATE TABLE `messages` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `sender` varchar(255) NOT NULL,
  `receiver` varchar(255) NOT NULL,
  `message` text NOT NULL,
  `timestamp` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
);

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "chatdb";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

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

$sender = $_POST['sender'];
$receiver = $_POST['receiver'];
$message = $_POST['message'];

$sql = "INSERT INTO messages (sender, receiver, message) VALUES ('$sender', '$receiver', '$message')";

if ($conn->query($sql) === TRUE) {
  echo "消息发送成功";
} else {
  echo "错误: " . $sql . "<br>" . $conn->error;
}

$conn->close();
?>

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "chatdb";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

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

$receiver = $_GET['receiver'];

$sql = "SELECT * FROM messages WHERE receiver = '$receiver' ORDER BY timestamp DESC LIMIT 50";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
  while($row = $result->fetch_assoc()) {
    echo "<b>" . $row["sender"] . "</b>: " . $row["message"] . "<br>";
  }
} else {
  echo "没有消息";
}

$conn->close();
?>