PHP を使用してオンライン Q&A コミュニティ機能を開発する方法

CREATE TABLE questions (
    id INT primary key auto_increment,
    title VARCHAR(255) NOT NULL,
    content TEXT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

CREATE TABLE answers (
    id INT primary key auto_increment,
    question_id INT NOT NULL,
    content TEXT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

<?php
// 连接数据库
$connection = new mysqli('localhost', 'username', 'password', 'database');

// 查询最新的问题列表
$result = $connection->query("SELECT * FROM questions ORDER BY created_at DESC");

// 输出问题列表
while ($row = $result->fetch_assoc()) {
    echo '<h3>'.$row['title'].'</h3>';
    echo '<p>'.$row['content'].'</p>';
}
?>

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    // 连接数据库
    $connection = new mysqli('localhost', 'username', 'password', 'database');

    // 获取用户输入
    $title = $_POST['title'];
    $content = $_POST['content'];

    // 将问题插入数据库
    $statement = $connection->prepare("INSERT INTO questions (title, content) VALUES (?, ?)");
    $statement->bind_param("ss", $title, $content);
    $statement->execute();

    // 跳转到首页
    header("Location: index.php");
    exit;
}
?>

<form method="POST" action="ask.php">
    <input type="text" name="title" placeholder="问题标题" required><br>
    <textarea name="content" placeholder="问题描述" required></textarea><br>
    <button type="submit">提交问题</button>
</form>

<?php
// 连接数据库
$connection = new mysqli('localhost', 'username', 'password', 'database');

// 根据问题ID查询问题和答案
$questionId = $_GET['id'];

$questionResult = $connection->query("SELECT * FROM questions WHERE id = $questionId");
$questionRow = $questionResult->fetch_assoc();

$answerResult = $connection->query("SELECT * FROM answers WHERE question_id = $questionId");

echo '<h3>'.$questionRow['title'].'</h3>';
echo '<p>'.$questionRow['content'].'</p>';

// 输出答案列表
while ($row = $answerResult->fetch_assoc()) {
    echo '<div>'.$row['content'].'</div>';
}
?>

<?php
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    // 连接数据库
    $connection = new mysqli('localhost', 'username', 'password', 'database');

    // 获取用户输入
    $content = $_POST['content'];
    $questionId = $_POST['question_id'];

    // 将答案插入数据库
    $statement = $connection->prepare("INSERT INTO answers (question_id, content) VALUES (?, ?)");
    $statement->bind_param("is", $questionId, $content);
    $statement->execute();

    // 跳转回问题页面
    header("Location: question.php?id=$questionId");
    exit;
}

$questionId = $_GET['id'];

echo '<form method="POST" action="answer.php">';
echo '<input type="hidden" name="question_id" value="'.$questionId.'">';
echo '<textarea name="content" placeholder="请输入您的回答"></textarea><br>';
echo '<button type="submit">提交回答</button>';
echo '</form>';