用sqlite建立日历，用户，记事，课程表

好的，以下是使用SQLite建立日历、用户、记事和课程表的示例代码：

1. 创建数据库和表

import sqlite3

# 连接数据库
conn = sqlite3.connect('calendar.db')

# 创建用户表
conn.execute('''CREATE TABLE users
             (id INTEGER PRIMARY KEY AUTOINCREMENT,
             username TEXT NOT NULL UNIQUE,
             password TEXT NOT NULL);''')

# 创建日历表
conn.execute('''CREATE TABLE calendar
             (id INTEGER PRIMARY KEY AUTOINCREMENT,
             user_id INTEGER NOT NULL,
             date TEXT NOT NULL,
             event TEXT NOT NULL,
             FOREIGN KEY(user_id) REFERENCES users(id));''')

# 创建记事表
conn.execute('''CREATE TABLE notes
             (id INTEGER PRIMARY KEY AUTOINCREMENT,
             user_id INTEGER NOT NULL,
             title TEXT NOT NULL,
             content TEXT NOT NULL,
             FOREIGN KEY(user_id) REFERENCES users(id));''')

# 创建课程表
conn.execute('''CREATE TABLE courses
             (id INTEGER PRIMARY KEY AUTOINCREMENT,
             user_id INTEGER NOT NULL,
             course_name TEXT NOT NULL,
             course_time TEXT NOT NULL,
             FOREIGN KEY(user_id) REFERENCES users(id));''')

# 提交更改
conn.commit()

# 关闭连接
conn.close()

2. 插入数据

# 连接数据库
conn = sqlite3.connect('calendar.db')

# 插入用户数据
conn.execute("INSERT INTO users (username, password) VALUES (?, ?)", ('user1', 'password1'))
conn.execute("INSERT INTO users (username, password) VALUES (?, ?)", ('user2', 'password2'))

# 插入日历数据
conn.execute("INSERT INTO calendar (user_id, date, event) VALUES (?, ?, ?)", (1, '2021-11-11', 'Veterans Day'))
conn.execute("INSERT INTO calendar (user_id, date, event) VALUES (?, ?, ?)", (2, '2022-12-25', 'Christmas Day'))

# 插入记事数据
conn.execute("INSERT INTO notes (user_id, title, content) VALUES (?, ?, ?)", (1, 'Note 1', 'This is the first note.'))
conn.execute("INSERT INTO notes (user_id, title, content) VALUES (?, ?, ?)", (2, 'Note 2', 'This is the second note.'))

# 插入课程表数据
conn.execute("INSERT INTO courses (user_id, course_name, course_time) VALUES (?, ?, ?)", (1, 'Math', 'Monday 10:00-11:30'))
conn.execute("INSERT INTO courses (user_id, course_name, course_time) VALUES (?, ?, ?)", (2, 'English', 'Wednesday 13:00-14:30'))

# 提交更改
conn.commit()

# 关闭连接
conn.close()

3. 查询数据

# 连接数据库
conn = sqlite3.connect('calendar.db')

# 查询所有用户
users = conn.execute("SELECT * FROM users").fetchall()
print("Users:")
for user in users:
    print(user)

# 查询所有日历事件
calendar_events = conn.execute("SELECT * FROM calendar").fetchall()
print("Calendar Events:")
for event in calendar_events:
    print(event)

# 查询所有记事
notes = conn.execute("SELECT * FROM notes").fetchall()
print("Notes:")
for note in notes:
    print(note)

# 查询所有课程表
courses = conn.execute("SELECT * FROM courses").fetchall()
print("Courses:")
for course in courses:
    print(course)

# 关闭连接
conn.close()

以上代码只是示例，你可以根据自己的需求进行修改和扩展。