Comment utiliser PHP pour la gestion de projet et le suivi des tâches

CREATE TABLE projects (
    id INT PRIMARY KEY AUTO_INCREMENT,
    title VARCHAR(255) NOT NULL,
    description TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE tasks (
    id INT PRIMARY KEY AUTO_INCREMENT,
    project_id INT,
    title VARCHAR(255) NOT NULL,
    description TEXT,
    status ENUM('todo', 'in_progress', 'completed') DEFAULT 'todo',
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (project_id) REFERENCES projects(id)
);

<?php
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}
?>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $title = $_POST["title"];
    $description = $_POST["description"];

    // 添加项目
    $sql = "INSERT INTO projects (title, description) VALUES ('$title', '$description')";
    if ($conn->query($sql) === TRUE) {
        echo "项目添加成功！";
    } else {
        echo "添加项目时出错：" . $conn->error;
    }

    // 添加任务
    $project_id = $conn->insert_id; // 获取刚插入的项目的ID
    $task_title = $_POST["task_title"];
    $task_description = $_POST["task_description"];

    $sql = "INSERT INTO tasks (project_id, title, description) VALUES ('$project_id', '$task_title', '$task_description')";
    if ($conn->query($sql) === TRUE) {
        echo "任务添加成功！";
    } else {
        echo "添加任务时出错：" . $conn->error;
    }
}
?>

<?php
// 获取所有项目
$sql = "SELECT * FROM projects";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while ($row = $result->fetch_assoc()) {
        echo "项目标题：" . $row["title"] . "<br>";
        echo "项目描述：" . $row["description"] . "<br>";

        // 获取该项目下的所有任务
        $project_id = $row["id"];
        $sql = "SELECT * FROM tasks WHERE project_id = $project_id";
        $task_result = $conn->query($sql);

        if ($task_result->num_rows > 0) {
            echo "任务列表：<br>";
            while ($task_row = $task_result->fetch_assoc()) {
                echo "- " . $task_row["title"] . "<br>";
                echo "任务描述：" . $task_row["description"] . "<br>";
                echo "任务状态：" . $task_row["status"] . "<br>";
            }
        } else {
            echo "该项目下暂无任务。<br>";
        }

        echo "<br>";
    }
} else {
    echo "暂无项目。";
}
?>