基于PHP的实时聊天系统的用户评分和好友推荐功能

CREATE TABLE `user_ratings` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` int(11) NOT NULL,
  `friend_id` int(11) NOT NULL,
  `rating` int(11) NOT NULL,
  PRIMARY KEY (`id`)
);

<button onclick="rateUser()">评分</button>
<script>
  function rateUser() {
    var friendId = prompt("请输入要评分的好友ID：");
    var rating = prompt("请输入评分值：");
    // 使用Ajax将评分信息发送到后台进行处理
    // 代码省略
  }
</script>

<?php
$friendId = $_POST['friendId'];
$rating = $_POST['rating'];

// 将评分信息插入到数据库中
$conn = new mysqli("localhost", "username", "password", "database");
$stmt = $conn->prepare("INSERT INTO user_ratings (user_id, friend_id, rating) VALUES (?, ?, ?)");
$stmt->bind_param("iii", $_SESSION['user_id'], $friendId, $rating);
$stmt->execute();
$stmt->close();
$conn->close();
?>

<?php
$userId = $_SESSION['user_id'];

// 获取用户评分数据
$conn = new mysqli("localhost", "username", "password", "database");
$stmt = $conn->prepare("SELECT friend_id, AVG(rating) as avg_rating FROM user_ratings WHERE user_id = ? GROUP BY friend_id");
$stmt->bind_param("i", $userId);
$stmt->execute();
$result = $stmt->get_result();

$ratings = array();
while ($row = $result->fetch_assoc()) {
  $ratings[$row['friend_id']] = $row['avg_rating'];
}

$result->close();
$stmt->close();

// 获取共同好友数量
$stmt = $conn->prepare("SELECT friend_id, COUNT(*) as common_friends FROM friends WHERE user_id = ? GROUP BY friend_id");
$stmt->bind_param("i", $userId);
$stmt->execute();
$result = $stmt->get_result();

$commonFriends = array();
while ($row = $result->fetch_assoc()) {
  $commonFriends[$row['friend_id']] = $row['common_friends'];
}

$result->close();
$stmt->close();
$conn->close();

// 根据评分和共同好友数量进行推荐
$recommendedFriends = array();
foreach ($ratings as $friendId => $rating) {
  if (isset($commonFriends[$friendId])) {
    $score = $rating * $commonFriends[$friendId];
    $recommendedFriends[$friendId] = $score;
  }
}

arsort($recommendedFriends);

foreach ($recommendedFriends as $friendId => $score) {
  // 输出推荐结果
  echo "好友ID：" . $friendId . "，推荐分数：" . $score . "<br>";
}
?>