Backend DevelopmentPHP TutorialHow to use PHP to develop a simple online question and answer systemHow to use PHP to develop a simple online question and answer system
How to use PHP to develop a simple online question and answer system?
In the Internet era, Q&A communities have become a common way for people to obtain various knowledge and solve problems. Many websites offer Q&A features where users can ask questions and get answers from other users. This article will introduce how to use PHP to develop a simple online question and answer system and provide specific code examples.
First, we need to create a database to store questions and answers. This can be achieved using MySQL or other relational databases. Below is an example SQL statement to create a question table and an answer table.
CREATE TABLE questions (
id INT AUTO_INCREMENT PRIMARY KEY,
title VARCHAR(255) NOT NULL,
content TEXT NOT NULL,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
CREATE TABLE answers (
id INT AUTO_INCREMENT PRIMARY KEY,
question_id INT NOT NULL,
content TEXT NOT NULL,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (question_id) REFERENCES questions(id)
);Next, we need to create a PHP file to handle the addition, deletion, modification and checking of questions and answers. The following is a simple sample code:
<?php
// 连接数据库
$host = 'localhost';
$db = 'question_answer';
$user = 'root';
$password = 'password';
$conn = new PDO("mysql:host=$host;dbname=$db", $user, $password);
// 添加问题
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['title']) && isset($_POST['content'])) {
$title = $_POST['title'];
$content = $_POST['content'];
$sql = "INSERT INTO questions (title, content) VALUES (?, ?)";
$stmt = $conn->prepare($sql);
$stmt->execute([$title, $content]);
$questionId = $conn->lastInsertId();
// 返回问题ID
echo json_encode(['questionId' => $questionId]);
exit;
}
// 获取问题和答案
if ($_SERVER['REQUEST_METHOD'] === 'GET' && isset($_GET['questionId'])) {
$questionId = $_GET['questionId'];
// 获取问题
$sql = "SELECT * FROM questions WHERE id = ?";
$stmt = $conn->prepare($sql);
$stmt->execute([$questionId]);
$question = $stmt->fetch(PDO::FETCH_ASSOC);
// 获取答案
$sql = "SELECT * FROM answers WHERE question_id = ?";
$stmt = $conn->prepare($sql);
$stmt->execute([$questionId]);
$answers = $stmt->fetchAll(PDO::FETCH_ASSOC);
// 返回问题和答案
echo json_encode(['question' => $question, 'answers' => $answers]);
exit;
}
// 添加答案
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['questionId']) && isset($_POST['content'])) {
$questionId = $_POST['questionId'];
$content = $_POST['content'];
$sql = "INSERT INTO answers (question_id, content) VALUES (?, ?)";
$stmt = $conn->prepare($sql);
$stmt->execute([$questionId, $content]);
// 返回成功
echo json_encode(['success' => true]);
exit;
}
// 删除问题
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['deleteQuestionId'])) {
$questionId = $_POST['deleteQuestionId'];
// 删除问题
$sql = "DELETE FROM questions WHERE id = ?";
$stmt = $conn->prepare($sql);
$stmt->execute([$questionId]);
// 删除相关答案
$sql = "DELETE FROM answers WHERE question_id = ?";
$stmt = $conn->prepare($sql);
$stmt->execute([$questionId]);
// 返回成功
echo json_encode(['success' => true]);
exit;
}
?>In the above code, we use PDO to connect to the database and use prepared statements to prevent SQL injection attacks.
Next, we can create a front-end page to display questions and answers, and provide the functionality to add and delete questions. The following is a simple front-end page example:
<!DOCTYPE html>
<html>
<head>
<title>在线问答系统</title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
</head>
<body>
<h1 id="在线问答系统">在线问答系统</h1>
<!-- 添加问题表单 -->
<form id="addQuestionForm">
<input type="text" name="title" placeholder="问题标题" required>
<textarea name="content" placeholder="问题内容" required></textarea>
<button type="submit">添加问题</button>
</form>
<!-- 问题列表 -->
<ul id="questionList"></ul>
<script>
// 添加问题
$('#addQuestionForm').submit(function(e) {
e.preventDefault();
$.post('qa.php', $(this).serialize(), function(response) {
// 更新问题列表
fetchQuestionList();
// 清空表单
$('#addQuestionForm')[0].reset();
}, 'json');
});
// 获取问题列表
function fetchQuestionList() {
$.get('qa.php', function(response) {
var questionList = '';
for (var i = 0; i < response.length; i++) {
var question = response[i];
var questionItem = '<li>'
+ '<h3 id="question-title">' + question.title + '</h3>'
+ '<p>' + question.content + '</p>'
+ '<button onclick="deleteQuestion(' + question.id + ')">删除</button>'
+ '</li>';
questionList += questionItem;
}
$('#questionList').html(questionList);
}, 'json');
}
// 删除问题
function deleteQuestion(questionId) {
if (confirm('确定要删除该问题及相关答案吗？')) {
$.post('qa.php', { deleteQuestionId: questionId }, function(response) {
fetchQuestionList();
}, 'json');
}
}
// 页面加载时获取问题列表
$(function() {
fetchQuestionList();
});
</script>
</body>
</html>In the above code, we use jQuery to send AJAX requests to communicate with the server, and use DOM operations to dynamically update the page content.
To sum up, through the above PHP and HTML code examples, we can implement a simple online question and answer system. Of course, this is just a basic example. The actual question and answer system also needs to consider more functional and security issues. I hope this article can help you get started with PHP development and inspire you to build a more complete online question and answer system.
The above is the detailed content of How to use PHP to develop a simple online question and answer system. For more information, please follow other related articles on the PHP Chinese website!
PHP Performance Tuning for High Traffic WebsitesMay 14, 2025 am 12:13 AMThesecrettokeepingaPHP-poweredwebsiterunningsmoothlyunderheavyloadinvolvesseveralkeystrategies:1)ImplementopcodecachingwithOPcachetoreducescriptexecutiontime,2)UsedatabasequerycachingwithRedistolessendatabaseload,3)LeverageCDNslikeCloudflareforservin
Dependency Injection in PHP: Code Examples for BeginnersMay 14, 2025 am 12:08 AMYou should care about DependencyInjection(DI) because it makes your code clearer and easier to maintain. 1) DI makes it more modular by decoupling classes, 2) improves the convenience of testing and code flexibility, 3) Use DI containers to manage complex dependencies, but pay attention to performance impact and circular dependencies, 4) The best practice is to rely on abstract interfaces to achieve loose coupling.
PHP Performance: is it possible to optimize the application?May 14, 2025 am 12:04 AMYes,optimizingaPHPapplicationispossibleandessential.1)ImplementcachingusingAPCutoreducedatabaseload.2)Optimizedatabaseswithindexing,efficientqueries,andconnectionpooling.3)Enhancecodewithbuilt-infunctions,avoidingglobalvariables,andusingopcodecaching
PHP Performance Optimization: The Ultimate GuideMay 14, 2025 am 12:02 AMThekeystrategiestosignificantlyboostPHPapplicationperformanceare:1)UseopcodecachinglikeOPcachetoreduceexecutiontime,2)Optimizedatabaseinteractionswithpreparedstatementsandproperindexing,3)ConfigurewebserverslikeNginxwithPHP-FPMforbetterperformance,4)
PHP Dependency Injection Container: A Quick StartMay 13, 2025 am 12:11 AMAPHPDependencyInjectionContainerisatoolthatmanagesclassdependencies,enhancingcodemodularity,testability,andmaintainability.Itactsasacentralhubforcreatingandinjectingdependencies,thusreducingtightcouplingandeasingunittesting.
Dependency Injection vs. Service Locator in PHPMay 13, 2025 am 12:10 AMSelect DependencyInjection (DI) for large applications, ServiceLocator is suitable for small projects or prototypes. 1) DI improves the testability and modularity of the code through constructor injection. 2) ServiceLocator obtains services through center registration, which is convenient but may lead to an increase in code coupling.
PHP performance optimization strategies.May 13, 2025 am 12:06 AMPHPapplicationscanbeoptimizedforspeedandefficiencyby:1)enablingopcacheinphp.ini,2)usingpreparedstatementswithPDOfordatabasequeries,3)replacingloopswitharray_filterandarray_mapfordataprocessing,4)configuringNginxasareverseproxy,5)implementingcachingwi
PHP Email Validation: Ensuring Emails Are Sent CorrectlyMay 13, 2025 am 12:06 AMPHPemailvalidationinvolvesthreesteps:1)Formatvalidationusingregularexpressionstochecktheemailformat;2)DNSvalidationtoensurethedomainhasavalidMXrecord;3)SMTPvalidation,themostthoroughmethod,whichchecksifthemailboxexistsbyconnectingtotheSMTPserver.Impl
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
SublimeText3 Chinese version
Chinese version, very easy to use
DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software
Zend Studio 13.0.1
Powerful PHP integrated development environment
PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
