#! /usr/bin/python

# -*- coding: UTF-8 -*-

"""

作者: 小肥巴巴

简书: https://www.jianshu.com/u/db796a501972

邮箱: [email protected]

github: https://github.com/xiaofeipapa/python_example

您可以任意转载, 恳请保留我作为原作者, 谢谢.

"""

from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index, Text

from sqlalchemy.orm import sessionmaker, relationship

from sqlalchemy import create_engine

from timeit import default_timer

host = 'localhost'

port = 3306

db = 'mysql_test'

user = 'mysql_test'

password = 'mysql_test'

g_mysql_url = 'mysql+pymysql://%s:%s@%s:%d/%s' % (user, password, host, port, db)

engine = create_engine(g_mysql_url)

Base = declarative_base()

class Product(Base):

__tablename__ = 'Product'

id = Column(Integer, primary_key=True, autoincrement=True)

name = Column(String(40))

remark = Column(String(1000), nullable=True)

isBuy = Column(Integer, default=1)

Base.metadata.create_all(engine) #创建表

Session = sessionmaker(bind=engine)

# =============== 以上为初始化数据库和表

# ---- 使用 with 的方式来优化代码

class UsingAlchemy(object):

def __init__(self, commit=True, log_time=True, log_label='总用时'):

"""

:param commit: 是否在最后提交事务(设置为False的时候方便单元测试)

:param log_time: 是否打印程序运行总时间

:param log_label: 自定义log的文字

"""

self._log_time = log_time

self._commit = commit

self._log_label = log_label

self._session = Session()

def __enter__(self):

# 如果需要记录时间

if self._log_time is True:

self._start = default_timer()

return self

def __exit__(self, *exc_info):

# 提交事务

if self._commit:

self._session.commit()

if self._log_time is True:

diff = default_timer() - self._start

print('-- %s: %.6f 秒' % (self._log_label, diff))

@property

def session(self):

return self._session