Python3访问MySQL数据库快速入门Demo

要实现一个简单的IM（即时通讯）系统，支持用户注册、登录和聊天记录存储，你可以使用Python和mysql 数据库。以下是一个基本的实现示例：要使用MySQL创建表并通过Python提供一个API服务，你可以使用Flask框架来实现API服务，并使用PyMySQL库来连接MySQL数据库。以下是一个基本的实现步骤：

1. 安装所需库

首先，确保你安装了Flask和PyMySQL库：

pip install flask pymysql

2. MySQL数据库设置

docker run --hostname=a5ddc3708f2e --env=MYSQL_ROOT_PASSWORD=123456 --env=MYSQL_DATABASE=jwordpress --env=TZ=Asia/Shanghai --env=LANG=en_US.UTF-8 --env=PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin --env=GOSU_VERSION=1.7 --env=MYSQL_MAJOR=5.7 --env=MYSQL_VERSION=5.7.26-1debian9 --volume=D:\IdeaProjects\Jwordpress-parent-s02-81f3dea303558f4388ef39435a52ea1cfab22904\docker\mysql\my.cnf:/etc/mysql/my.cnf:rw --volume=D:\IdeaProjects\Jwordpress-parent-s02-81f3dea303558f4388ef39435a52ea1cfab22904\docker\mysql\init-file.sql:/etc/mysql/init-file.sql:rw --volume=D:\IdeaProjects\Jwordpress-parent-s02-81f3dea303558f4388ef39435a52ea1cfab22904\docker\mysql\data:/var/lib/mysql:rw --volume=D:\IdeaProjects\Jwordpress-parent-s02-81f3dea303558f4388ef39435a52ea1cfab22904\docker\mysql\docker-entrypoint-initdb.d:/docker-entrypoint-initdb.d:rw --volume=/var/lib/mysql --network=docker_default -p 3306:3306 --restart=unless-stopped --label='com.docker.compose.config-hash=f33622a4d32e092d39a39c3dc0bd2259df09b24ad897567bcaa7f7fa0630b019' --label='com.docker.compose.container-number=1' --label='com.docker.compose.depends_on=' --label='com.docker.compose.image=sha256:a1aa4f76fab910095dfcf4011f32fbe7acdb84c46bb685a8cf0a75e7d0da8f6b' --label='com.docker.compose.oneoff=False' --label='com.docker.compose.project=docker' --label='com.docker.compose.project.config_files=D:\IdeaProjects\Jwordpress-parent-s02-81f3dea303558f4388ef39435a52ea1cfab22904\docker\docker-compose.yml' --label='com.docker.compose.project.working_dir=D:\IdeaProjects\Jwordpress-parent-s02-81f3dea303558f4388ef39435a52ea1cfab22904\docker' --label='com.docker.compose.service=mysql' --label='com.docker.compose.version=2.21.0' --runtime=runc -d registry.cn-hangzhou.aliyuncs.com/zhengqing/mysql:5.7

假设你已经在MySQL中创建了一个数据库，接下来创建用户和消息表。

CREATE DATABASE chat_db;USE chat_db;CREATE TABLE users (id INT AUTO_INCREMENT PRIMARY KEY,username VARCHAR(255) UNIQUE NOT NULL,password VARCHAR(255) NOT NULL
);CREATE TABLE messages (id INT AUTO_INCREMENT PRIMARY KEY,sender VARCHAR(255) NOT NULL,receiver VARCHAR(255) NOT NULL,message TEXT NOT NULL,timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
);

3. 创建Flask API服务

一个简单的Flask应用，提供注册、登录和发送消息的API。详见main.py

from flask import Flask, request, jsonify
import pymysql
import bcryptapp = Flask(__name__)# Database connection configuration
db_config = {'host': 'localhost','user': 'root','password': '123456','database': 'chat_db'
}def get_db_connection():return pymysql.connect(**db_config)@app.route('/register', methods=['POST'])
def register():data = request.jsonusername = data['username']password = data['password']hashed = bcrypt.hashpw(password.encode('utf-8'), bcrypt.gensalt())conn = get_db_connection()cursor = conn.cursor()try:cursor.execute("INSERT INTO users (username, password) VALUES (%s, %s)", (username, hashed))conn.commit()return jsonify({'message': 'Registration successful!'}), 201except pymysql.IntegrityError:return jsonify({'message': 'Username already exists!'}), 400finally:cursor.close()conn.close()@app.route('/login', methods=['POST'])
def login():data = request.jsonusername = data['username']password = data['password']conn = get_db_connection()cursor = conn.cursor()try:cursor.execute("SELECT password FROM users WHERE username = %s", (username,))result = cursor.fetchone()if result and bcrypt.checkpw(password.encode('utf-8'), result[0].encode('utf-8')):return jsonify({'message': 'Login successful!'}), 200else:return jsonify({'message': 'Incorrect username or password!'}), 401finally:cursor.close()conn.close()@app.route('/send_message', methods=['POST'])
def send_message():data = request.jsonsender = data['sender']receiver = data['receiver']message = data['message']conn = get_db_connection()cursor = conn.cursor()cursor.execute("INSERT INTO messages (sender, receiver, message) VALUES (%s, %s, %s)", (sender, receiver, message))conn.commit()cursor.close()conn.close()return jsonify({'message': 'Message sent successfully!'}), 201@app.route('/get_messages', methods=['GET'])
def get_messages():user1 = request.args.get('user1')user2 = request.args.get('user2')conn = get_db_connection()cursor = conn.cursor()cursor.execute('''SELECT sender, receiver, message, timestamp FROM messages WHERE (sender = %s AND receiver = %s) OR (sender = %s AND receiver = %s)ORDER BY timestamp''', (user1, user2, user2, user1))messages = cursor.fetchall()cursor.close()conn.close()return jsonify(messages), 200if __name__ == '__main__':app.run(debug=True)

4. 运行API服务

将上述代码保存为一个Python文件（例如main.py），然后运行：

python main.py

这将启动一个Flask开发服务器，你可以通过POST请求来注册和登录用户，通过GET请求来获取聊天记录。

5. 测试

post http://127.0.0.1:5000/register

{"username": "alice","password": "password123"
}

post http://127.0.0.1:5000/register

{"username": "bob","password": "password123"
}

post http://127.0.0.1:5000/send_message

{"sender": "alice","receiver": "bob","message": "Hello Bob!"
}

get http://127.0.0.1:5000/get_messages?user1=alice&user2=bob

[["alice","bob","Hello Bob!","Fri, 15 Nov 2024 16:06:33 GMT"]
]

请注意，这个示例是一个基本实现，适用于学习和测试。在生产环境中，你需要考虑更多的安全性和性能优化，例如使用HTTPS、添加身份验证令牌等。