How to use PHP and CGI to implement a website's comment and like system

How to use PHP and CGI to implement the comment and like system of the website

With the rapid development of social media, the comment and like system on the website has become an indispensable function. This article will introduce how to use PHP and CGI (Common Gateway Interface) to implement the website's comment and like system, and attach relevant code examples.

1. Database design

First, we need to design a database to store data related to comments and likes. We can create two tables: "comments" and "likes". The comments table contains fields: id (comment ID, auto-incremented primary key), name (commenter name), email (commenter email address), content (comment content) and created_at (comment creation time); the likes table contains fields: id (point Like ID, auto-incremented primary key), comment_id (comment ID, foreign key, id field associated with comments table), ip_address (user IP address) and created_at (like creation time).

Use the following SQL statements to create these two tables:

CREATE TABLE comments (
  id INT AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(255) NOT NULL,
  email VARCHAR(255) NOT NULL,
  content TEXT NOT NULL,
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE likes (
  id INT AUTO_INCREMENT PRIMARY KEY,
  comment_id INT NOT NULL,
  ip_address VARCHAR(255) NOT NULL,
  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (comment_id) REFERENCES comments(id)
);

2. Display comments and likes

Display comments and likes on the website’s pages function, we can use PHP to query the database and get the number of comments and likes from the results.

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");

// 查询评论数据
$query = "SELECT * FROM comments";
$result = mysqli_query($conn, $query);
$comments = mysqli_fetch_all($result, MYSQLI_ASSOC);

// 查询点赞数量
$query = "SELECT comment_id, COUNT(*) as likes_count FROM likes GROUP BY comment_id";
$result = mysqli_query($conn, $query);
$likes = mysqli_fetch_all($result, MYSQLI_ASSOC);

// 输出评论和点赞信息
foreach ($comments as $comment) {
  echo "评论者：" . $comment['name'] . "<br>";
  echo "评论时间：" . $comment['created_at'] . "<br>";
  echo "评论内容：" . $comment['content'] . "<br>";

  // 查找对应评论的点赞数量
  $likes_count = 0;
  foreach ($likes as $like) {
    if ($like['comment_id'] == $comment['id']) {
      $likes_count = $like['likes_count'];
      break;
    }
  }

  echo "点赞数量：" . $likes_count . "<br><br>";
}

// 关闭数据库连接
mysqli_close($conn);
?>

3. Add comments and likes

In order to implement the functions of comments and likes, we can use HTML forms and PHP scripts to receive user comments and likes request and insert data into the database. The following is an example HTML form:

<form method="POST" action="submit.php">
  <input type="text" name="name" placeholder="姓名">
  <input type="email" name="email" placeholder="邮箱">
  <textarea name="content" placeholder="评论内容"></textarea>
  <input type="submit" value="提交评论">
</form>

Then, we can create a PHP script named "submit.php" to handle the request to submit a comment:

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");

// 接收表单数据
$name = $_POST['name'];
$email = $_POST['email'];
$content = $_POST['content'];

// 插入评论数据
$query = "INSERT INTO comments (name, email, content) VALUES ('$name', '$email', '$content')";
mysqli_query($conn, $query);

// 关闭数据库连接
mysqli_close($conn);

// 重定向到原页面
header("Location: index.php");
exit();
?>

4. Processing point Like Request

To handle like requests, we can create a PHP script called "like.php" and link it to the corresponding like button.

<?php
// 连接数据库
$conn = mysqli_connect("localhost", "username", "password", "database");

// 获取用户IP地址
$ip_address = $_SERVER['REMOTE_ADDR'];

// 获取评论ID
$comment_id = $_GET['comment_id'];

// 插入点赞数据
$query = "INSERT INTO likes (comment_id, ip_address) VALUES ($comment_id, '$ip_address')";
mysqli_query($conn, $query);

// 关闭数据库连接
mysqli_close($conn);

// 重定向到原页面
header("Location: index.php");
exit();
?>

In the HTML code for the comment and like buttons, link it to like.php and pass the corresponding comment ID:

<a href="like.php?comment_id=<?php echo $comment['id']; ?>">点赞</a>

With the above four steps, we can use PHP and CGI implements the website’s comment and like system. Users can submit comments through a form and like comments. The data of comments and likes will be stored in the database and can be displayed on the website pages. Through the above sample code, you can modify and extend it accordingly according to your needs.

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