Bagaimana untuk menambah fungsi kerjasama berbilang pengguna pada sistem perakaunan - Bagaimana untuk membangunkan kerjasama berbilang pengguna menggunakan PHP

id (int) // 用户ID
username (varchar) // 用户名
password (varchar) // 密码

id (int) // 账目ID
user_id (int) // 用户ID（外键，关联users表）
title (varchar) // 账目标题
description (text) // 账目描述
amount (decimal) // 金额

id (int) // 权限ID
user_id (int) // 用户ID（外键，关联users表）
account_id (int) // 账目ID（外键，关联accounts表）

// 注册
if (isset($_POST['register'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];

    // 检查用户名是否已存在
    $checkUsernameQuery = "SELECT id FROM users WHERE username = '$username'";
    $checkUsernameResult = mysqli_query($con, $checkUsernameQuery);

    if (mysqli_num_rows($checkUsernameResult) > 0) {
        echo "用户名已存在";
    } else {
        // 插入新用户
        $insertUserQuery = "INSERT INTO users (username, password) VALUES ('$username', '$password')";
        mysqli_query($con, $insertUserQuery);

        echo "注册成功";
    }
}

// 登录
if (isset($_POST['login'])) {
    $username = $_POST['username'];
    $password = $_POST['password'];

    // 检查用户名和密码是否匹配
    $checkUserQuery = "SELECT id FROM users WHERE username = '$username' AND password = '$password'";
    $checkUserResult = mysqli_query($con, $checkUserQuery);

    if (mysqli_num_rows($checkUserResult) > 0) {
        echo "登录成功";
    } else {
        echo "用户名或密码错误";
    }
}

// 添加权限
if (isset($_POST['add_permission'])) {
    $account_id = $_POST['account_id'];
    $user_id = $_POST['user_id'];

    // 检查用户是否有权限修改该账目的权限
    // 这里需要根据实际情况进行权限判断，例如只有账目的创建者才能添加权限
    $checkPermissionQuery = "SELECT id FROM permissions WHERE account_id = '$account_id' AND user_id = '$currentUserId'";
    $checkPermissionResult = mysqli_query($con, $checkPermissionQuery);

    if (mysqli_num_rows($checkPermissionResult) > 0) {
        // 添加权限
        $insertPermissionQuery = "INSERT INTO permissions (user_id, account_id) VALUES ('$user_id', '$account_id')";
        mysqli_query($con, $insertPermissionQuery);

        echo "添加权限成功";
    } else {
        echo "您没有权限添加权限";
    }
}

// 删除权限
if (isset($_POST['delete_permission'])) {
    $permission_id = $_POST['permission_id'];

    // 检查用户是否有权限删除该权限
    // 这里需要根据实际情况进行权限判断，例如只有账目的创建者或权限的创建者才能删除权限
    $checkPermissionQuery = "SELECT id FROM permissions WHERE id = '$permission_id' AND (user_id = '$currentUserId' OR account_id = '$currentAccountId')";
    $checkPermissionResult = mysqli_query($con, $checkPermissionQuery);

    if (mysqli_num_rows($checkPermissionResult) > 0) {
        // 删除权限
        $deletePermissionQuery = "DELETE FROM permissions WHERE id = '$permission_id'";
        mysqli_query($con, $deletePermissionQuery);

        echo "删除权限成功";
    } else {
        echo "您没有权限删除该权限";
    }
}

// 显示账目列表
$getAccountsQuery = "SELECT a.id, a.title, a.description, a.amount FROM accounts a, permissions p WHERE p.user_id = '$currentUserId' AND p.account_id = a.id";
$getAccountsResult = mysqli_query($con, $getAccountsQuery);

while ($row = mysqli_fetch_assoc($getAccountsResult)) {
    echo "账目标题：" . $row['title'] . "<br>";
    echo "账目描述：" . $row['description'] . "<br>";
    echo "账目金额：" . $row['amount'] . "<br>";
    echo "<br>";
}

// 编辑账目
if (isset($_POST['edit_account'])) {
    $account_id = $_POST['account_id'];
    $title = $_POST['title'];
    $description = $_POST['description'];
    $amount = $_POST['amount'];

    // 检查用户是否有权限编辑该账目
    $checkPermissionQuery = "SELECT id FROM permissions WHERE account_id = '$account_id' AND user_id = '$currentUserId'";
    $checkPermissionResult = mysqli_query($con, $checkPermissionQuery);

    if (mysqli_num_rows($checkPermissionResult) > 0) {
        // 更新账目信息
        $updateAccountQuery = "UPDATE accounts SET title = '$title', description = '$description', amount = '$amount' WHERE id = '$account_id'";
        mysqli_query($con, $updateAccountQuery);

        echo "账目编辑成功";
    } else {
        echo "您没有权限编辑该账目";
    }
}