python学习课程（八）sqlalchemy的classic映射

python学习教程（八）sqlalchemy的classic映射

首先，我们来创建一个配置文件，其中包含数据库中表的映射关系，文件名为：dbsetting.py

from sqlalchemy.orm import mapper
from sqlalchemy import Table, MetaData, Column, Integer, String, DateTime
from datetime import datetime
from sqlalchemy.engine import create_engine
'''the connection to the database'''
engine = create_engine("mysql://root:1933jld1945js@localhost/test",isolation_level="READ UNCOMMITTED") 
'''the construct of the database table'''
metadata = MetaData()
people = Table( #people
                'people', metadata,
                Column('id', Integer, primary_key=True),
                Column('name', String(16), unique=True, nullable=False),
                Column('gender', String(255), unique=True, nullable=True),
                Column('created', DateTime, default=datetime.now)
                )
student = Table( #student
                'student', metadata,
                Column('id', Integer, primary_key=True),
                Column('name', String(16), unique=True, nullable=False),
                Column('gender', String(255), unique=True, nullable=True),
                Column('created', DateTime, default=datetime.now)
                )
teacher = Table( #teacher
                'teacher', metadata,
                Column('id', Integer, primary_key=True),
                Column('name', String(16), unique=True, nullable=False),
                Column('gender', String(255), unique=True, nullable=True),
                Column('created', DateTime, default=datetime.now)
                )
'''create database class'''
class People(object):pass
class Student(object):pass
class Teacher(object):pass
'''classic'''
mapper(People,people)
mapper(Student,student)
mapper(Teacher,teacher)
'''create tables'''
metadata.create_all(engine)

然后，我们可以写一个文件，测试一下，文件代码如下：

from dbproject.dbsetting import People,Teacher,engine
from sqlalchemy.orm import sessionmaker

people = People()
teahcer = Teacher()
people.name='renlei'
people.id=1
teahcer.name='laoshi'
teahcer.id=1
Session = sessionmaker()
Session.configure(bind=engine)
session = Session()
session.add(people)
session.add(teahcer)
session.flush()
session.commit()