mysql 缓存失效机制

import redis
import mysql.connector

# 连接 Redis
redis_client = redis.StrictRedis(host='localhost', port=6379, db=0)

# 连接 MySQL
mysql_conn = mysql.connector.connect(user='user', password='password', host='localhost', database='test')
mysql_cursor = mysql_conn.cursor()

def get_data(key):
    # 先从 Redis 缓存中获取数据
    data = redis_client.get(key)
    if data is not None:
        return data.decode('utf-8')
    
    # 如果缓存中没有数据，从 MySQL 数据库中获取
    mysql_cursor.execute("SELECT data FROM table WHERE key = %s", (key,))
    result = mysql_cursor.fetchone()
    if result is not None:
        data = result[0]
        # 将数据存入 Redis 缓存
        redis_client.setex(key, 3600, data)  # 设置缓存有效期为 1 小时
        return data
    
    return None

def update_data(key, new_data):
    # 更新 MySQL 数据库中的数据
    mysql_cursor.execute("UPDATE table SET data = %s WHERE key = %s", (new_data, key))
    mysql_conn.commit()
    
    # 手动失效 Redis 缓存
    redis_client.delete(key)

# 示例调用
data = get_data('some_key')
print(data)

update_data('some_key', 'new_data')