二手回收网站利用PHP开发的后台管理系统简化操作流程

-- 创建用户表
CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(255) NOT NULL,
    password VARCHAR(255) NOT NULL
);

-- 创建订单表
CREATE TABLE orders (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT NOT NULL,
    product_name VARCHAR(255) NOT NULL,
    price DECIMAL(10, 2) NOT NULL,
    status ENUM('pending', 'shipped', 'delivered') NOT NULL,
    FOREIGN KEY (user_id) REFERENCES users(id)
);

<?php
// 数据库配置
$servername = "localhost";
$username = "root";
$password = "123456";
$dbname = "example";

// 创建数据库连接
$conn = new mysqli($servername, $username, $password, $dbname);

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

// 处理用户登录逻辑
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $username = $_POST["username"];
    $password = $_POST["password"];

    $sql = "SELECT * FROM users WHERE username='$username' AND password='$password'";
    $result = $conn->query($sql);

    if ($result->num_rows > 0) {
        // 登录成功
    } else {
        // 登录失败
    }
}
?>

<?php
// 获取用户列表
$sql = "SELECT * FROM users";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "ID: " . $row["id"]. " - 用户名: " . $row["username"]. "<br>";
    }
} else {
    echo "没有用户";
}
?>

<?php
// 获取订单列表
$sql = "SELECT * FROM orders";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "ID: " . $row["id"]. " - 商品名: " . $row["product_name"]. " - 价格: " . $row["price"]. "<br>";
    }
} else {
    echo "没有订单";
}
?>

<?php
// 添加新用户
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $username = $_POST["username"];
    $password = $_POST["password"];

    $sql = "INSERT INTO users (username, password) VALUES ('$username', '$password')";
    if ($conn->query($sql) === TRUE) {
        echo "新用户添加成功";
    } else {
        echo "新用户添加失败：" . $conn->error;
    }
}
?>

<?php
// 编辑用户信息
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $user_id = $_POST["user_id"];
    $username = $_POST["username"];
    $password = $_POST["password"];

    $sql = "UPDATE users SET username='$username', password='$password' WHERE id='$user_id'";
    if ($conn->query($sql) === TRUE) {
        echo "用户信息更新成功";
    } else {
        echo "用户信息更新失败：" . $conn->error;
    }
}
?>