数据库扩展双十一活动

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

# 主库（写操作）
write_engine = create_engine('mysql+pymysql://user:password@write_host/dbname')
WriteSession = sessionmaker(bind=write_engine)

# 从库（读操作）
read_engine = create_engine('mysql+pymysql://user:password@read_host/dbname')
ReadSession = sessionmaker(bind=read_engine)

# 写操作示例
def write_data(data):
    session = WriteSession()
    try:
        # 执行写操作
        session.add(data)
        session.commit()
    except:
        session.rollback()
        raise
    finally:
        session.close()

# 读操作示例
def read_data():
    session = ReadSession()
    try:
        # 执行读操作
        result = session.query(DataModel).all()
        return result
    finally:
        session.close()