Detailed explanation of online voting system developed by PHP-PHP Tutorial-php.cn

Detailed explanation of online voting system developed by PHP

王林

Release： 2023-08-09 15:30:01

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Detailed explanation of online voting system developed by PHP

Detailed explanation of the online voting system developed by PHP

The voting system is a very common function on the Internet. It is widely used in various online activities, surveys, Scenarios such as elections. This article will introduce in detail how to use PHP to develop a simple online voting system.

Create database

First, we need to create a database to store voting-related data. Suppose our database is named "vote" and contains the following two tables:

"polls": a table used to store information such as voting topics and deadlines.
"options": A table used to store each voting option, related to the polls table through foreign keys.

The following is the SQL sample code to create the database and table:

CREATE DATABASE vote;

USE vote;

CREATE TABLE polls (
  id INT AUTO_INCREMENT PRIMARY KEY,
  title VARCHAR(255) NOT NULL,
  deadline DATE NOT NULL
);

CREATE TABLE options (
  id INT AUTO_INCREMENT PRIMARY KEY,
  poll_id INT,
  title VARCHAR(255) NOT NULL,
  votes INT DEFAULT 0,
  FOREIGN KEY (poll_id) REFERENCES polls(id)
);

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Writing the voting page

The next step is to write the front-end page, using To display voting topics and options and receive votes from users. The following is a simple HTML and PHP code example:

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>在线投票系统</title>
</head>
<body>
  <h1>投票主题</h1>
  
  <?php
  // 连接数据库
  $conn = mysqli_connect("localhost", "username", "password", "vote");
  
  // 查询投票主题和选项
  $poll_id = $_GET['poll_id'];
  $poll_query = "SELECT * FROM polls WHERE id = $poll_id";
  $poll_result = mysqli_query($conn, $poll_query);
  
  if (mysqli_num_rows($poll_result) > 0) {
    // 显示投票主题
    $poll = mysqli_fetch_assoc($poll_result);
    echo "<h2>{$poll['title']}</h2>";
    
    // 查询投票选项
    $options_query = "SELECT * FROM options WHERE poll_id = $poll_id";
    $options_result = mysqli_query($conn, $options_query);
    
    if (mysqli_num_rows($options_result) > 0) {
      // 显示投票选项
      echo "<form method='POST' action='vote.php'>";
      while ($option = mysqli_fetch_assoc($options_result)) {
        echo "<input type='radio' name='option_id' value='{$option['id']}'>{$option['title']}<br>";
      }
      echo "<input type='hidden' name='poll_id' value='$poll_id'>";
      echo "<input type='submit' value='提交投票'>";
      echo "</form>";
    } else {
      echo "没有投票选项。";
    }
  } else {
    echo "投票主题不存在。";
  }
  
  // 关闭数据库连接
  mysqli_close($conn);
  ?>
  
</body>
</html>

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Handling voting requests

In the voting page, we use a file called "vote.php" Handler to receive and process the user's vote request. The following is a sample code:

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

// 根据用户的投票选项，更新选项的票数
$option_id = $_POST['option_id'];
$poll_id = $_POST['poll_id'];

$update_query = "UPDATE options SET votes = votes + 1 WHERE id = $option_id";
mysqli_query($conn, $update_query);

// 关闭数据库连接
mysqli_close($conn);

// 重定向到结果页面
header("Location: results.php?poll_id=$poll_id");
exit();
?>

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When the user submits a vote, vote.php will update the number of votes for the option and redirect to a page named "results.php" to display the voting results.

Display voting results

Finally, we need to write a results page to display the voting results. The following is a simple PHP code example:

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>投票结果</title>
</head>
<body>
  <h1>投票结果</h1>
  
  <?php
  // 连接数据库
  $conn = mysqli_connect("localhost", "username", "password", "vote");
  
  // 查询投票主题和选项
  $poll_id = $_GET['poll_id'];
  $poll_query = "SELECT * FROM polls WHERE id = $poll_id";
  $poll_result = mysqli_query($conn, $poll_query);
  
  if (mysqli_num_rows($poll_result) > 0) {
    // 显示投票主题
    $poll = mysqli_fetch_assoc($poll_result);
    echo "<h2>{$poll['title']}（截止日期：{$poll['deadline']}）</h2>";
    
    // 查询投票选项
    $options_query = "SELECT * FROM options WHERE poll_id = $poll_id";
    $options_result = mysqli_query($conn, $options_query);
    
    if (mysqli_num_rows($options_result) > 0) {
      // 显示投票选项和票数
      while ($option = mysqli_fetch_assoc($options_result)) {
        echo "{$option['title']}: {$option['votes']} 票<br>";
      }
    } else {
      echo "没有投票选项。";
    }
  } else {
    echo "投票主题不存在。";
  }
  
  // 关闭数据库连接
  mysqli_close($conn);
  ?>
  
</body>
</html>

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The above is a detailed introduction to a simple online voting system developed using PHP. By combining the database and the front-end page, we can simply implement the user voting function and count and display the voting results. Of course, actual voting systems may require more features and security measures to meet specific needs, but the examples provided in this article can be used as a reference to get started in developing a basic voting system.

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