sqlalchemy多线程访问数据库

from sqlalchemy import Column, String, create_engine,Integer
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base

# 创建对象的基类:
Base = declarative_base()

# 定义User对象:
class Book(Base):
    # 表的名字:
    __tablename__ = \'novel_book\'

    # 表的结构:
    id = Column(Integer, primary_key=True, autoincrement=True)
    provide_name = Column(String(45))
    start_url = Column(String(45))
    state = Column(Integer)
    

# 初始化数据库连接:
engine = create_engine(\'mysql+pymysql://root:%s@localhost:3306/springboot\' % sql_password,pool_size=10)  # 有10个线程并发访问如果没有指定pool_size （默认是5）会有部分线程timeout 无法获取connection
# 创建DBSession类型:
DBSession = sessionmaker(bind=engine)