How to develop online voting function using PHP

How to use PHP to develop online voting functions

In modern society, online voting has become a common way to collect public opinions and make decisions. PHP, as a popular server-side scripting language, can be easily used to develop online voting functions. This article will introduce how to use PHP to develop a simple online voting system, and attach corresponding code examples.

1. Database design

First, we need to design a database for storing voting information. Suppose we need to create a database named "votes" and create a data table named "polls" to store voting option information. The structure of the data table "polls" is as follows:

polls table

id (INT) -- voting option ID
name (VARCHAR) -- voting option name
votes (INT ) -- Number of votes

2. Create voting options

Display voting options on the web page for users to choose, which can be achieved through the following PHP code:

<?php
// 连接数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "votes";
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查数据库连接是否成功
if ($conn->connect_error) {
    die("数据库连接失败: " . $conn->connect_error);
}

// 查询投票选项
$sql = "SELECT id, name FROM polls";
$result = $conn->query($sql);

// 展示投票选项
if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "<input type='radio' name='option' value='" . $row["id"] . "'>" . $row["name"] . "<br>";
    }
} else {
    echo "没有投票选项可供选择";
}

// 关闭数据库连接
$conn->close();
?>

3. Processing voting results

Next, we need to process the user's voting selections and update the number of votes in the database. The following is the relevant PHP code example:

<?php
// 连接数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "votes";
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查数据库连接是否成功
if ($conn->connect_error) {
    die("数据库连接失败: " . $conn->connect_error);
}

// 获取用户的投票选择
$optionID = $_POST["option"];

// 更新投票数
$sql = "UPDATE polls SET votes = votes + 1 WHERE id = " . $optionID;

if ($conn->query($sql) === TRUE) {
    echo "投票成功";
} else {
    echo "投票失败: " . $conn->error;
}

// 关闭数据库连接
$conn->close();
?>

4. Display voting results

Finally, we can use the following PHP code to display the results of the current voting options:

<?php
// 连接数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "votes";
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查数据库连接是否成功
if ($conn->connect_error) {
    die("数据库连接失败: " . $conn->connect_error);
}

// 查询投票结果
$sql = "SELECT name, votes FROM polls";
$result = $conn->query($sql);

// 展示投票结果
if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo $row["name"] . "：" . $row["votes"] . "票<br>";
    }
} else {
    echo "目前还没有投票结果";
}

// 关闭数据库连接
$conn->close();
?>

Through the above steps, we successfully developed a simple online voting function using PHP. You can make further improvements and extensions based on actual needs, such as adding a voting deadline, limiting the number of votes per user, etc. I wish you success in developing an online voting system that suits you!

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