Second-hand recycling website uses high-quality user evaluation system developed in PHP

Second-hand recycling website uses high-quality user evaluation system developed by PHP

With the rapid development of the second-hand recycling market, more and more people are paying attention to how to identify and select high-quality second-hand trading platforms. In order to provide more reliable reference opinions, many second-hand recycling websites have begun to introduce user evaluation systems.

This article will introduce the implementation method of a high-quality user evaluation system developed using PHP and provide relevant code examples.

First, we need to create a database to store user evaluation-related data. Assume that we already have a database named evaluation, and create a table named users to store user information, and a table named feedbackThe table is used to store user evaluation data.

CREATE TABLE users (
   id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
   username VARCHAR(30) NOT NULL,
   email VARCHAR(50) NOT NULL,
   password VARCHAR(30) NOT NULL
);

CREATE TABLE feedback (
   id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
   user_id INT(6) UNSIGNED,
   comment VARCHAR(255) NOT NULL,
   rating INT(1) NOT NULL,
   FOREIGN KEY (user_id) REFERENCES users(id)
);

Next, we need to create a PHP class to handle the logic related to user evaluation.

class FeedbackSystem {
   private $db;

   public function __construct($db) {
      $this->db = $db;
   }

   public function addFeedback($user_id, $comment, $rating) {
      $sql = "INSERT INTO feedback (user_id, comment, rating) VALUES ($user_id, '$comment', $rating)";
      $result = $this->db->query($sql);
      return $result;
   }

   public function getFeedbacks($user_id) {
      $sql = "SELECT * FROM feedback WHERE user_id = $user_id";
      $result = $this->db->query($sql);
      return $result->fetch_all(MYSQLI_ASSOC);
   }

   public function calculateAverageRating($user_id) {
      $sql = "SELECT AVG(rating) AS average_rating FROM feedback WHERE user_id = $user_id";
      $result = $this->db->query($sql);
      return $result->fetch_assoc()['average_rating'];
   }
}

In the above code, we created a class named FeedbackSystem, which contains the functions of adding reviews, getting reviews and calculating the average rating. The constructor accepts a database connection object and saves it in the private variable $db for use by subsequent methods.

Now, we can use the above class at the appropriate location on the website to implement the user evaluation function.

// 用户发表评价
$feedbackSystem = new FeedbackSystem($db);
$feedbackSystem->addFeedback($user_id, $comment, $rating);

// 获取用户评价
$feedbacks = $feedbackSystem->getFeedbacks($user_id);
foreach ($feedbacks as $feedback) {
   echo $feedback['comment'];
   echo $feedback['rating'];
}

// 计算平均评分
$averageRating = $feedbackSystem->calculateAverageRating($user_id);
echo "平均评分：" . $averageRating;

In the above code, an instance of FeedbackSystem is first created and a new user evaluation is added by calling the addFeedback method. Next, use the getFeedbacks method to get all the reviews of a specific user, and loop through the output comments and ratings. Finally, the average rating is calculated and output by calling the calculateAverageRating method.

Through the above implementation, second-hand recycling websites can create a high-quality user evaluation system to provide users with more reliable reference information and help them make more informed choices. At the same time, by using PHP language and database storage technology, we can implement functions such as adding, obtaining and calculating evaluations, and provide relevant code examples for readers' reference.

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