如何在mysql中开发日程管理系统数据库

CREATE TABLE users (
  id INT AUTO_INCREMENT PRIMARY KEY,
  username VARCHAR(50) NOT NULL UNIQUE,
  email VARCHAR(100) NOT NULL UNIQUE,
  password_hash VARCHAR(255) NOT NULL,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
<p>CREATE TABLE events (
id INT AUTO_INCREMENT PRIMARY KEY,
title VARCHAR(255) NOT NULL,
description TEXT,
start_time DATETIME NOT NULL,
end_time DATETIME NOT NULL,
user_id INT NOT NULL,
status ENUM('active', 'cancelled') DEFAULT 'active',
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
INDEX idx_start_time (start_time),
INDEX idx_user_status (user_id, status),
INDEX idx_time_range (start_time, end_time)
);</p>

SELECT * FROM events 
WHERE user_id = 1 
  AND DATE(start_time) = '2025-04-05'
  AND status = 'active';

SELECT * FROM events 
WHERE user_id = 1 
  AND start_time BETWEEN NOW() AND DATE_ADD(NOW(), INTERVAL 7 DAY)
  AND status = 'active';

SELECT id FROM events 
WHERE user_id = 1 
  AND status = 'active'
  AND NOT (end_time < '2025-04-05 10:00:00' OR start_time > '2025-04-05 11:00:00');