How to develop a simple voting system using PHP

How to use PHP to develop a simple voting system, specific code examples are required

Introduction:
With the development of the Internet, the application of voting systems has become increasingly popular, regardless of Whether for market research, elections or event voting, an easy-to-use and efficient voting system is essential. As a popular programming language, PHP can help us quickly develop a simple and fully functional voting system. This article will introduce how to develop a simple voting system using PHP and provide specific code examples.

1. System functional requirements analysis:
Before we start writing code, we need to clarify the system requirements and functions. A basic voting system should have the following functions:

1. User registration and login functions.
2. Create poll topics and options.
3. Users can browse and participate in voting.
4. Display voting results.

2. Database design:
In order to save user information, voting topics and options, and voting results, we need to design database tables. The following is a simple database design example:

1. Users table (users):

   • id: user ID, integer type, primary key
   • username: username, string type
   • password: password, string type
   • created_at: creation time, date and time type

2. Voting topic table (polls):

   • id: voting topic ID, integer type, primary key
   • title: voting topic title, string type
   • created_by: created User ID, integer type (associated with the user table)
   • created_at: creation time, datetime type

3. Voting options table (options):

   • id: option ID, integer type, primary key
   • poll_id: voting topic ID, integer type (associated with the voting topic table)
   • option_text: option text, string type

4. Voting result table (votes):

   • id: voting result ID, integer type, primary key
   • poll_id: vote Topic ID, integer type (associated with the voting topic table)
   • option_id: option ID, integer type (associated with the voting option table)
   • user_id: user ID, integer type (associated with the user table) )

3. System development steps:

1. Create the database and connect:
   First, we need to create a database named "voting_system" database and connect to the database:

   $conn = mysqli_connect("localhost", "root", "", "voting_system");
   if (!$conn) {
       die("数据库连接失败：" . mysqli_connect_error());
   }

2. User registration and login functions:
   Users need to be able to register and log in to the system. Here is a simple code example:

   a. User registration:

   $username = $_POST['username'];
   $password = $_POST['password'];
   
   $hashed_password = password_hash($password, PASSWORD_DEFAULT);
   
   $sql = "INSERT INTO users (username, password) VALUES ('$username', '$hashed_password')";
   
   if (mysqli_query($conn, $sql)) {
       echo "注册成功！";
   } else {
       echo "注册失败：" . mysqli_error($conn);
   }

   b. User login:

   $username = $_POST['username'];
   $password = $_POST['password'];
   
   $sql = "SELECT * FROM users WHERE username='$username'";
   $result = mysqli_query($conn, $sql);
   
   if (mysqli_num_rows($result) > 0) {
       $row = mysqli_fetch_assoc($result);
       if (password_verify($password, $row['password'])) {
           echo "登录成功！";
       } else {
           echo "密码错误！";
       }
   } else {
       echo "用户不存在！";
   }

3. Create polling topics and options:
   Creating voting topics and options requires users to be logged in and have corresponding permissions. The following is a simple code example:

   a. Create a voting topic:

   $title = $_POST['title'];
   $created_by = $_SESSION['user_id'];
   
   $sql = "INSERT INTO polls (title, created_by) VALUES ('$title', '$created_by')";
   
   if (mysqli_query($conn, $sql)) {
       echo "投票主题创建成功！";
   } else {
       echo "投票主题创建失败：" . mysqli_error($conn);
   }

   b. Create a voting option:

   $poll_id = $_POST['poll_id'];
   $option_text = $_POST['option_text'];
   
   $sql = "INSERT INTO options (poll_id, option_text) VALUES ('$poll_id', '$option_text')";
   
   if (mysqli_query($conn, $sql)) {
       echo "投票选项创建成功！";
   } else {
       echo "投票选项创建失败：" . mysqli_error($conn);
   }

4. User participation in voting:
   Users need to browse the voting topic and select the voting option to vote. Here is a simple code example:

   a. Display voting topics and options:

   $sql = "SELECT * FROM polls";
   $result = mysqli_query($conn, $sql);
   
   while ($row = mysqli_fetch_assoc($result)) {
       echo "投票主题：" . $row['title'] . "<br>";
   
       $poll_id = $row['id'];
       $sql_options = "SELECT * FROM options WHERE poll_id='$poll_id'";
       $result_options = mysqli_query($conn, $sql_options);
   
       while ($row_option = mysqli_fetch_assoc($result_options)) {
           echo "<input type='checkbox' name='option_ids[]' value='" . $row_option['id'] . "'>" . $row_option['option_text'] . "<br>";
       }
   
       echo "<hr>";
   }

   b. Handle user votes:

   $option_ids = $_POST['option_ids'];
   
   foreach ($option_ids as $option_id) {
       $sql = "INSERT INTO votes (poll_id, option_id, user_id) VALUES ('$poll_id', '$option_id', '$user_id')";
   
       if (mysqli_query($conn, $sql)) {
           echo "投票成功！";
       } else {
           echo "投票失败：" . mysqli_error($conn);
       }
   }

5. Display voting results :
   The voting results can be achieved by counting the number of votes for each option. The following is a simple code example:

   a. Statistical voting results:

   $poll_id = $_GET['poll_id'];
   
   $sql = "SELECT option_id, COUNT(*) AS vote_count FROM votes WHERE poll_id='$poll_id' GROUP BY option_id";
   $result = mysqli_query($conn, $sql);
   
   while ($row = mysqli_fetch_assoc($result)) {
       $option_id = $row['option_id'];
       $vote_count = $row['vote_count'];
   
       $sql_option = "SELECT option_text FROM options WHERE id='$option_id'";
       $result_option = mysqli_query($conn, $sql_option);
       $row_option = mysqli_fetch_assoc($result_option);
   
       echo $row_option['option_text'] . ": " . $vote_count . " 票<br>";
   }

Conclusion:
This article introduces how to use PHP to develop a simple voting system, and provides specific code examples. Through the above steps, we can implement basic voting system functions such as user registration and login, creating voting topics and options, user participation in voting, and displaying voting results. According to actual needs, we can also carry out further optimization and expansion. Hope this article helps you!

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