SQLAlchemy MySQL 基础

__author__ = 'Steve'



from sqlalchemy import create_engine

from sqlalchemy.orm import sessionmaker

from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy import Column, Integer, String



Base = declarative_base()





# define the schema of table

class Users2(Base):

    __tablename__ = 'users2'

    name = Column(String(45), nullable=True)

    id = Column(Integer, primary_key=True)





# you can direct query database, but it is not recommended

def test_conn():

    username = 'root'

    passwd = '123'

    schema = 'test'

    engine = create_engine(

        "mysql://{0}:{1}@127.0.0.1/{2}?charset=utf8&use_unicode=0".format(username, passwd, schema))

    result = engine.execute("select name from users2")

    for row in result:

        print "name:", row['name']

    result.close()





def conn():

    username = 'root'

    passwd = '123'

    schema = 'test'

    engine = create_engine(

        "mysql+mysqldb://{0}:{1}@127.0.0.1/{2}?charset=utf8&use_unicode=0".format(username, passwd, schema))

    Base.metadata.bind = engine

    DBSession = sessionmaker(bind=engine)

    session = DBSession()

    return session





def query():

    session = conn()

    rows = session.query(Users2).all()

    for row in rows:

        print row.id, row.name





def insert():

    user = Users2(name="steve", id=3)

    session = conn()

    session.add(user)

    session.commit()





def delete():

    session = conn()

    user = session.query(Users2).filter_by(name='steve2').one()

    print "delete user:", user.name

    session.delete(user)

    session.commit()





def update():

    session = conn()

    user = session.query(Users2).filter_by(name='steve').one()

    user.name = 'steve2'

    session.commit()





if __name__ == "__main__":

    query()

    print

    # insert()

    # delete()

    # update()

    query()