sqlalchemy+postgreSQL（relationship）

 

1、连接数据库

import os,sys

PROJECT_ROOT = os.path.dirname(os.path.realpath(__file__))

sys.path.insert(0, os.path.join(PROJECT_ROOT, 'lib'))





CONFIG_PATH = os.path.join(PROJECT_ROOT,'config.cfg')

from sqlalchemy import create_engine

from sqlalchemy.ext.declarative import declarative_base

import ConfigParser





cf = ConfigParser.ConfigParser()

cf.read(CONFIG_PATH)





print cf.get("db","db_host")





if cf.get("db","db_host"):

db_host=cf.get("db","db_host")

else:

db_host= "127.0.0.1"  //之前用localhost 报错链接不上数据库 注意





if cf.get("db","db_type"):

db_type= cf.get("db","db_type")

else:

db_type="postgresql+psycopg2"





 



if cf.get("db","db_name"):

db_name=cf.get("db","db_name")

else:

db_name="luoyun"





if cf.get("db","db_user"):

db_user = cf.get("db","db_user")

else:

db_user = "luoyun"



if cf.get("db","db_password"):

db_password = cf.get("db","db_password")

else:

db_password = "luoyun"



str= "%s://%s:%s@%s/%s" % (db_type, db_user,db_password,db_host,db_name)

#dbengine = create_engine('postgresql+psycopg2://luoyun:[email protected]/luoyun',echo=True,client_encoding='utf8')

dbengine = create_engine(str,echo=True,client_encoding='utf8')



from sqlalchemy import create_engine

from sqlalchemy.ext.declarative import declarative_base



ORMBase = declarative_base()



from sqlalchemy.orm import sessionmaker



Session = sessionmaker(bind=dbengine)



dbsession = Session()

db = dbsession

2、定义数据表和类之间的映射关系

import lyorm

from sqlalchemy import Column, Integer, String, ForeignKey

from sqlalchemy.orm import relationship, backref

from lyorm import ORMBase



class User(ORMBase):

     __tablename__='users'

     id = Column(Integer,primary_key=True)

     name = Column(String)

     fullname = Column(String)

     password = Column(String)

     def __init__(self, name, fullname, password):

         self.name = name

         self.fullname = fullname

         self.password = password

     def __repr__(self):

         return "<User('%s','%s','%s')>" % (self.name,self.fullname,self.password)



class Address(ORMBase):

      __tablename__= 'address'

      id = Column(Integer, primary_key=True)

      email_address = Column(String, nullable=False)

      user_id = Column(Integer, ForeignKey('users.id'))

      user = relationship("User", backref = backref('addresses',order_by=id))



      def __init__(self,email_address):

          self.email_address = email_address

      def __repr__(self):

           return "<Address('%s')>" % self.email_address

　　3、配置文件  

[db]

db_host = 127.0.0.1

db_type = postgresql+psycopg2

db_name = luoyun

db_user = luoyun

db_password = luoyun

　　4、初始化数据库 python manage.py

import models

from lyorm import ORMBase, dbengine,dbsession

ORMBase.metadata.create_all(dbengine)

from models import User



def init():



   jack = User('jack','Jack Bean', '801310')

   dbsession.add(jack)

   dbsession.commit()

if __name__=='__main__':

  init()