from __future__ import print_function
import datetime

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


# connect to an database:
engine = create_engine('sqlite:///:memory:', echo=False)
# declarative base class for our mapping:
Base = declarative_base()
# Session class is ORMs handle to the database:
Session = sessionmaker(bind=engine)


class Tester(Base):
    __tablename__ = 'tester'
    id = Column(Integer, primary_key=True)
    some = Column(Integer, default=0)
    last_update = Column(DateTime, default=datetime.datetime.utcnow,
        onupdate=datetime.datetime.utcnow)


if __name__ == '__main__':
    # to have a conversation with our db create a Session instance:
    session = Session()
    # create tables in the database via the MetaData registy:
    Base.metadata.create_all(engine)
    t = Tester()
    session.add(t)
    session.commit()