PHP 从入门到精通:程序员全方位实战教程(含项目案例与性能优化)

location ~ \.php$ {

include snippets/fastcgi-php.conf;

fastcgi_pass unix:/run/php/php8.3-fpm.sock;

}

$name = "张三"; // 字符串

$age = 25; // 整数

$score = 92.5; // 浮点数

$isStudent = true; // 布尔值

$hobbies = ["篮球", "编程"]; // 数组

$user = null; // 空值

// foreach遍历索引数组

foreach ($hobbies as $hobby) {

echo $hobby . " "; // 输出：篮球 编程

}

// 关联数组

$userInfo = ["name" => "李四", "age" => 30];

echo $userInfo["name"]; // 输出：李四

// if-else

if ($age < 18) {

echo "未成年";

} elseif ($age >= 18 && $age < 30) {

echo "青年";

} else {

echo "成年";

}

// switch

switch ($age) {

case 20:

echo "20岁";

break;

case 25:

echo "25岁";

break;

default:

echo "其他年龄";

}

// for循环

for ($i = 1; $i <= 5; $i++) {

echo "循环第" . $i . "次<br>";

}

// while循环

$num = 1;

while ($num <= 3) {

echo "数字：" . $num . "<br>";

$num++;

}

// do-while循环（至少执行一次）

$count = 0;

do {

echo "计数：" . $count . "<br>";

$count++;

} while ($count < 2);

// 定义函数：计算两数之和

function add($a, $b) {

return $a + $b;

}

// 调用函数

$result = add(10, 20);

echo $result; // 输出：30

function getInfo($name, $age = 18) { // age默认值18

echo "姓名：" . $name . "，年龄：" . $age;

}

getInfo("王五"); // 输出：姓名：王五，年龄：18

function increment(&$num) {

$num++;

}

$x = 5;

increment($x);

echo $x; // 输出：6（$x的值被修改）

// 定义User类

class User {

// 公共属性（外部可访问）

public $name;

// 私有属性（仅类内部可访问）

private $age;

// 构造方法（创建对象时自动调用）

public function __construct($name, $age) {

$this->name = $name; // $this表示当前对象

$this->age = $age;

}

// 公共方法：获取年龄（私有属性通过方法访问）

public function getAge() {

return $this->age;

}

// 公共方法：修改年龄

public function setAge($newAge) {

if ($newAge > 0 && $newAge < 150) {

$this->age = $newAge;

}

}

// 公共方法：输出用户信息

public function showInfo() {

echo "姓名：" . $this->name . "，年龄：" . $this->age;

}

}

// 创建User对象

$user1 = new User("赵六", 28);

// 访问属性和方法

echo $user1->name; // 输出：赵六

$user1->setAge(29);

$user1->showInfo(); // 输出：姓名：赵六，年龄：29

// 定义子类Admin（继承User类）

class Admin extends User {

// 新增属性

public $role;

// 重写构造方法（调用父类构造方法用parent::__construct()）

public function __construct($name, $age, $role) {

parent::__construct($name, $age);

$this->role = $role;

}

// 重写父类showInfo方法（多态体现）

public function showInfo() {

echo "管理员姓名：" . $this->name . "，年龄：" . $this->getAge() . "，角色：" . $this->role;

}

// 新增方法：管理员权限

public function manage() {

echo $this->name . "拥有系统管理权限";

}

}

// 创建Admin对象

$admin1 = new Admin("钱七", 35, "超级管理员");

$admin1->showInfo(); // 输出：管理员姓名：钱七，年龄：35，角色：超级管理员

$admin1->manage(); // 输出：钱七拥有系统管理权限

try {

// 连接数据库（DSN格式：数据库类型:host=主机;dbname=数据库名;charset=编码）

$pdo = new PDO("mysql:host=localhost;dbname=test_db;charset=utf8mb4", "root", "123456");

// 设置错误模式为抛出异常（便于调试）

$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

echo "PDO连接成功";

} catch (PDOException $e) {

die("连接失败：" . $e->getMessage());

}

// 面向对象方式

$mysqli = new mysqli("localhost", "root", "123456", "test_db");

if ($mysqli->connect_error) {

die("连接失败：" . $mysqli->connect_error);

}

$mysqli->set_charset("utf8mb4");

echo "MySQLi连接成功";

// 关闭连接（PDO和MySQLi均会自动关闭，也可手动关闭）

$mysqli->close();

$pdo = null;

// 预处理SQL（:name为占位符）

$stmt = $pdo->prepare("INSERT INTO users (name, age, email) VALUES (:name, :age, :email)");

// 绑定参数

$stmt->bindParam(":name", $name);

$stmt->bindParam(":age", $age);

$stmt->bindParam(":email", $email);

// 赋值并执行

$name = "孙八";

$age = 22;

$email = "sun8@example.com";

$stmt->execute();

// 获取插入的自增ID

$insertId = $pdo->lastInsertId();

echo "插入成功，用户ID：" . $insertId;

// 查询单条数据

$stmt = $pdo->prepare("SELECT * FROM users WHERE id = :id");

$stmt->execute(["id" => 1]);

$user = $stmt->fetch(PDO::FETCH_ASSOC); // 返回关联数组

echo "用户姓名：" . $user["name"];

// 查询多条数据

$stmt = $pdo->query("SELECT * FROM users WHERE age > 20");

$users = $stmt->fetchAll(PDO::FETCH_ASSOC);

foreach ($users as $u) {

echo "ID：" . $u["id"] . "，姓名：" . $u["name"] . "<br>";

}

// 更新数据

$stmt = $pdo->prepare("UPDATE users SET age = :age WHERE id = :id");

$stmt->execute(["age" => 23, "id" => 1]);

echo "更新成功，影响行数：" . $stmt->rowCount();

// 删除数据

$stmt = $pdo->prepare("DELETE FROM users WHERE id = :id");

$stmt->execute(["id" => 2]);

echo "删除成功，影响行数：" . $stmt->rowCount();

<!-- form.html（表单页面） -->

<form action="handle_form.php" method="post">

用户名：<input type="text" name="username" required><br>

密码：<input type="password" name="password" required><br>

<button type="submit">提交</button>

</form>

<!-- handle_form.php（处理页面） -->

<?php

// 获取表单数据

$username = $_POST["username"];

$password = $_POST["password"]; // 实际开发中需加密存储，如password_hash()

// 简单验证

if ($username === "admin" && $password === "admin123") {

echo "登录成功，欢迎" . $username;

} else {

echo "用户名或密码错误";

}

?>

// 开启Session（必须放在脚本最顶部，无输出前）

session_start();

// 设置Session变量

$_SESSION["username"] = "admin";

$_SESSION["isLogin"] = true;

// 读取Session变量

if ($_SESSION["isLogin"]) {

echo "当前登录用户：" . $_SESSION["username"];

}

// 销毁Session

// 方式1：删除单个Session变量

unset($_SESSION["username"]);

// 方式2：清空所有Session变量

$_SESSION = [];

// 方式3：销毁Session（彻底删除Session文件）

session_destroy();

// 设置Cookie（参数：名称、值、过期时间（秒）、路径、域名、是否HTTPS传输）

setcookie("user_token", "abc123xyz", time() + 3600, "/", "", false, true); // 最后一个参数true表示仅HTTP访问，防JS读取

// 读取Cookie

if (isset($_COOKIE["user_token"])) {

echo "Cookie值：" . $_COOKIE["user_token"];

}

// 删除Cookie（设置过期时间为过去）

setcookie("user_token", "", time() - 3600, "/");

CREATE TABLE `users` (

`id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户ID',

`username` varchar(50) NOT NULL COMMENT '用户名',

`email` varchar(100) NOT NULL COMMENT '邮箱',

`password` varchar(255) NOT NULL COMMENT '加密密码',

`create_time` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',

PRIMARY KEY (`id`),

UNIQUE KEY `username` (`username`),

UNIQUE KEY `email` (`email`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='用户表';

<?php

require_once "db.php"; // 引入数据库连接文件

session_start();

if ($_SERVER["REQUEST_METHOD"] === "POST") {

$username = trim($_POST["username"]);

$email = trim($_POST["email"]);

$password = $_POST["password"];

$confirmPwd = $_POST["confirm_password"];

// 表单验证

$errors = [];

if (empty($username)) $errors[] = "用户名不能为空";

if (!filter_var($email, FILTER_VALIDATE_EMAIL)) $errors[] = "邮箱格式错误";

if (strlen($password) < 6) $errors[] = "密码至少6位";

if ($password !== $confirmPwd) $errors[] = "两次密码不一致";

// 验证用户名/邮箱是否已存在

$stmt = $pdo->prepare("SELECT * FROM users WHERE username = :username OR email = :email");

$stmt->execute(["username" => $username, "email" => $email]);

if ($stmt->rowCount() > 0) $errors[] = "用户名或邮箱已被注册";

if (empty($errors)) {

// 密码加密（password_hash()生成哈希值，password_verify()验证）

$hashedPwd = password_hash($password, PASSWORD_DEFAULT);

// 插入数据

$stmt = $pdo->prepare("INSERT INTO users (username, email, password) VALUES (:username, :email, :password)");

$stmt->execute([

"username" => $username,

"email" => $email,

"password" => $hashedPwd

]);

$_SESSION["success"] = "注册成功，请登录";

header("Location: login.php"); // 跳转到登录页

exit;

} else {

$_SESSION["errors"] = $errors;

}

}

?>

<!-- 注册表单视图 -->

<!DOCTYPE html>

<html>

<head>

<title>用户注册</title>

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css">

</head>

<body>

<div class="container mt-5">

<h2>用户注册</h2>

<!-- 显示错误信息 -->

<?php if (isset($_SESSION["errors"])): ?>

<div class="alert alert-danger">

<?php foreach ($_SESSION["errors"] as $error): ?>

<p><?php echo $error ?></p>

<?php endforeach; unset($_SESSION["errors"]); ?>

</div>

<?php endif; ?>

<form method="post">

<div class="mb-3">

<label>用户名</label>

<input type="text" name="username" class="form-control" required>

</div>

<div class="mb-3">

<label>邮箱</label>

<input type="email" name="email" class="form-control" required>

</div>

<div class="mb-3">

<label>密码</label>

<input type="password" name="password" class="form-control" required>

</div>

<div class="mb-3">

<label>确认密码</label>

<input type="password" name="confirm_password" class="form-control" required>

</div>

<button type="submit" class="btn btn-primary">注册</button>

<a href="login.php" class="btn btn-link">已有账号？登录</a>

</form>

</div>

</body>

</html>

// login.php（登录逻辑）

session_start();

require_once "db.php";

if ($_SERVER["REQUEST_METHOD"] === "POST") {

$username = $_POST["username"];

$password = $_POST["password"];

// 查询用户

$stmt = $pdo->prepare("SELECT * FROM users WHERE username = :username");

$stmt->execute(["username" => $username]);

$user = $stmt->fetch(PDO::FETCH_ASSOC);

// 验证密码

if ($user && password_verify($password, $user["password"])) {

$_SESSION["user"] = $user; // 存储用户信息到Session

header("Location: user_list.php");

exit;

} else {

$_SESSION["error"] = "用户名或密码错误";

}

}

// user_list.php（用户列表，需登录才能访问）

session_start();

// 未登录则跳转到登录页

if (!isset($_SESSION["user"])) {

header("Location: login.php");

exit;

}

require_once "db.php";

// 查询所有用户

$stmt = $pdo->query("SELECT id, username, email, create_time FROM users ORDER BY create_time DESC");

$users = $stmt->fetchAll(PDO::FETCH_ASSOC);

opcache.enable=1

opcache.memory_consumption=128

opcache.max_accelerated_files=10000

// 生成Token并存储到Session

$_SESSION["csrf_token"] = bin2hex(random_bytes(32));

// 表单中添加Token

<input type="hidden" name="csrf_token" value="<?php echo $_SESSION["csrf_token"]; ?>">

// 验证Token

if ($_POST["csrf_token"] !== $_SESSION["csrf_token"]) {

die("CSRF攻击检测：Token验证失败");

}