python第六十六天--sqlalchemy

 #!usr/bin/env python
 #-*-coding:utf-8-*-
 # Author calmyan
 #python
 #2017/7/6    21:29
 #__author__='Administrator'
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
 from sqlalchemy.orm import sessionmaker, relationship
 from sqlalchemy import create_engine
 from sqlalchemy import func #统计

 #                                         用户 密码  主机             库
 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test",encoding="utf-8",echo=False)

 Base = declarative_base()#生成orm 基类
 class User_2(Base):
     __tablename__='user' #表名
     id = Column(Integer,primary_key=True)#整数类型  设为主键
     name = Column(String(32))#字符串类型
     age = Column(Integer)
     addr= Column(String(256))

     def __repr__(self):#输出查询
         return '%s>name:%s--age:%saddrs:%s'%(self.id,self.name,self.age,self.addr)

 Session_class=sessionmaker(bind=engine)#创建与数据库的会话 类
 Session=Session_class()#生成实例

 #增加
 '''
 user_obj =User(name="sa2",addrs="1234")#生成你要创建的数据对象
 Session.add(user_obj)# 添加记录
 '''
 #添加一组数据
 '''
 Session.add_all([
     User(name="abcg",age=34,addr="sdfsdf"),
     User(name="bcdq",age=11,addr="chaense")
 ])
 '''
 #删除
 '''
 Session.query(User).filter(User.id>3).filter(User.id<6).delete()
 '''
 #              查询        条件            所有
 data =Session.query(User_2).filter_by(id=2).all()
 #                                 多个条件
 data2 =Session.query(User_2).filter(User_2.id>2).filter(User_2.id<5).all()

 #改

 Session.query(User_2).filter(User_2.id ==2).update({"name" : ""})
 print(data)
 print(data2)
 '''
 print(Session.query(User).filter(User.id>2).filter(User.name.in_(["sa",'sa2'])).all())
 Session.rollback()#回滚操作
 print(Session.query(User).filter(User.id>2).filter(User.name.in_(["sa",'sa2'])).all())
 '''
 print(Session.query(User_2).filter(User_2.id>2).filter(User_2.name.in_(["sa",'sa2'])).count())#统计符合条件出现的次数
 counts=Session.query(User_2).filter(User_2.id>2).filter(User_2.name.in_(['bcd'])).count()#统计符合条件出现的次数
 print(counts)
 #分组查询              字段        统计次数                  字段
 gurps=Session.query(User_2.name,func.count(User_2.name)).group_by(User_2.name).all()
 print(gurps)
 #                                                              以addrs为条件
 gurps1=Session.query(User_2.name,func.count(User_2.name)).group_by(User_2.addr).all()
 print(gurps1)

 Session.commit()#关闭事务

sqlalchemy 基本操作

 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
 from sqlalchemy.orm import sessionmaker, relationship
 from sqlalchemy import create_engine
 #                                         用户 密码  主机             库
 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test",encoding="utf-8",echo=True)

 Base = declarative_base()#生成orm 基类
 class User(Base):
     __tablename__='info_l' #表名
     id = Column(Integer,primary_key=True)#整数类型  设为主键
     name = Column(String(32))#字符串类型
     addrs= Column(String(256))

 Base.metadata.create_all(engine)#创建表结构

 Session_class=sessionmaker(bind=engine)#创建与数据库的会话 类
 Session=Session_class()#生成实例

 user_obj =User(name="sa",addrs="")#生成你要创建的数据对象
 print(user_obj.name,user_obj.addrs)#此时并未创建对象
 Session.add(user_obj)#开启事务进行连接 添加记录
 Session.commit()#关闭事务

外键操作示例

 #!usr/bin/env python
 #-*-coding:utf-8-*-
 # Author calmyan
 #python
 #2017/7/7    10:28
 #__author__='Administrator'
 import sqlalchemy
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index,DATE
 from sqlalchemy.orm import sessionmaker, relationship
 from sqlalchemy import create_engine
 #                                         用户 密码  主机             库
 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test",encoding="utf-8",echo=False)

 Base = declarative_base()#生成orm 基类

 class Studes(Base):#学生类
     __tablename__ ='studes'
     id = Column(Integer,primary_key=True)#整数类型  设为主键
     name = Column(String(32),nullable=False)#字符串类型 不能为空
     register_day= Column(DATE,nullable=False)#日期

     def __repr__(self):#输出查询
         return '%s>name:%s--register_day :%s'%(self.id,self.name,self.register_day)

 class Studes_Cr(Base):#课程类
     __tablename__ ='stud_cr'
     id = Column(Integer,primary_key=True)#整数类型  设为主键
     day= Column(Integer,nullable=False)
     status= Column(String(35),nullable=False)#上课记录
     stu_id= Column(Integer,ForeignKey("studes.id",))#外键关联
     studes=relationship("Studes",backref="m_study_reg")#自定义关联反查

     def __repr__(self):#输出查询         自定义 外键关联调用
         return '%s>day:%s  status:%s'%(self.studes.name,self.day,self.status)

 Base.metadata.create_all(engine)#创建表结构

 Session_class=sessionmaker(bind=engine)#创建与数据库的会话 类
 Session=Session_class()#生成实例

 '''
 s1 = Studes(name="Alex",register_day='2017-05-06')#学生
 s2 = Studes(name="bolg",register_day='2017-03-06')
 s3 = Studes(name="calm",register_day='2017-01-07')
 s4 = Studes(name="Defr",register_day='2017-03-16')
 s5 = Studes(name="Eale",register_day='2017-02-24')

 study_obj1=Studes_Cr(day=1,status="YES",stu_id=1)#上课记录
 study_obj2=Studes_Cr(day=1,status="YES",stu_id=2)#上课记录
 study_obj3=Studes_Cr(day=1,status="NO",stu_id=3)#上课记录
 study_obj4=Studes_Cr(day=1,status="YES",stu_id=4)#上课记录
 study_obj5=Studes_Cr(day=2,status="NO",stu_id=1)#上课记录
 study_obj6=Studes_Cr(day=2,status="YES",stu_id=2)#上课记录
 study_obj7=Studes_Cr(day=2,status="YES",stu_id=3)#上课记录

 #一次全部添加
 Session.add_all([s1,s2,s3,s4,s5,study_obj1,study_obj2,study_obj3,study_obj4,study_obj5,study_obj6,study_obj7])
 '''

 #查询 学生对应的信息
 stu_obj= Session.query(Studes).filter(Studes.name=="Alex").first()
 print(stu_obj)
 #通过外键进行相关信息查询
 print(stu_obj.m_study_reg)

 Session.commit()

外键 多外键关联示例:   多外键关联.py  多外键_操作.py

多外键关联.py

 #!usr/bin/env python
 #-*-coding:utf-8-*-
 # Author calmyan
 #python
 #2017/7/7    13:06
 #__author__='Administrator'

 from sqlalchemy import Integer, ForeignKey, String, Column
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy.orm import relationship
 from sqlalchemy import create_engine

 Base = declarative_base()#生成orm 基类
 class Customer(Base):
     __tablename__ = 'customer'
     id = Column(Integer, primary_key=True)
     name = Column(String(32),nullable=False)

     billing_address_id = Column(Integer, ForeignKey("address.id"))#帐单地址外键关联
     shipping_address_id = Column(Integer, ForeignKey("address.id"))#收货地址外键关联

     billing_address = relationship("Address",foreign_keys=[billing_address_id])#帐单地址自定义反查 对应外键
     shipping_address = relationship("Address",foreign_keys=[shipping_address_id])#收货地址

 class Address(Base):
     __tablename__ = 'address'
     id = Column(Integer, primary_key=True)
     street = Column(String(32))#详细
     city = Column(String(32))#市
     state = Column(String(255))#省

     def __repr__(self):
         return self.state+self.city+self.street

 #                                         用户 密码  主机             库
 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test",encoding="utf-8",echo=False)

 Base.metadata.create_all(engine)#创建表结构

多外键_操作.py

 #!usr/bin/env python
 #-*-coding:utf-8-*-
 # Author calmyan
 #python
 #2017/7/7    13:21
 #__author__='Administrator'
 import os ,sys
 from day66 import 多外键关联
 from sqlalchemy.orm import relationship,sessionmaker
 from sqlalchemy import create_engine
 Session_class=sessionmaker(bind=多外键关联.engine)#创建与数据库的会话 类
 Session=Session_class()#生成实例
 '''
 addr1=多外键关联.Address(street="btxw",city='xy',state="fj")
 addr2=多外键关联.Address(street="jjqy",city='qz',state="fj")
 addr3=多外键关联.Address(street="ml",city='pt',state="fj")

 Session.add_all([addr1,addr2,addr3])#写入数据库

 c1=多外键关联.Customer(name='calmyan',billing_address=addr1,shipping_address=addr1)
 c2=多外键关联.Customer(name='alex',billing_address=addr3,shipping_address=addr2)
 Session.add_all([c1,c2])
 '''

 #查询
 sobj=Session.query(多外键关联.Customer).filter(多外键关联.Customer.name=='calmyan').first()

 print(sobj.name,sobj.billing_address,sobj.shipping_address)

 Session.commit()

多对多外键示例:

orm_s.py

 #!usr/bin/env python
 #-*-coding:utf-8-*-
 # Author calmyan
 #python
 #2017/7/7    14:07
 #__author__='Administrator'

 #一本书可以有多个作者，一个作者又可以出版多本书

 from sqlalchemy import Table, Column, Integer,String,DATE, ForeignKey
 from sqlalchemy.orm import relationship
 from sqlalchemy.ext.declarative import declarative_base
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker

 Base = declarative_base()

 #创建第三张表,自动维护
 book_m2m_author = Table('book_m2m_author', Base.metadata,
                         Column('book_id',Integer,ForeignKey('books.id')),#关联外键,书id
                         Column('author_id',Integer,ForeignKey('authors.id')),#关联外键,作者id
                         )

 class Book(Base):#书名
     __tablename__ = 'books'
     id = Column(Integer,primary_key=True)
     name = Column(String(64))
     pub_date = Column(DATE)
     authors = relationship('Author',secondary=book_m2m_author,backref='books')

     def __repr__(self):
         return self.name

 class Author(Base):#作者
     __tablename__ = 'authors'
     id = Column(Integer, primary_key=True)
     name = Column(String(32))

     def __repr__(self):
         return self.name

 #                                         用户 密码  主机             库
 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test?charset=utf8",encoding="utf-8",echo=False)

 Base.metadata.create_all(engine)#创建表结构

orm_s_aut.py

 #!usr/bin/env python
 #-*-coding:utf-8-*-
 # Author calmyan
 #python
 #2017/7/7    14:38
 #__author__='Administrator'

 from  day66 import orm_s
 from sqlalchemy.orm import relationship,sessionmaker
 Session_class = sessionmaker(bind=orm_s.engine) #创建与数据库的会话session class ,注意,这里返回给session的是个class,不是实例
 s = Session_class() #生成session实例
 '''
 #book名
 b1 = orm_s.Book(name="跟Alex学Python")
 b2 = orm_s.Book(name="跟Alex学把妹")
 b3 = orm_s.Book(name="跟Alex学装逼")
 b4 = orm_s.Book(name="跟Alex学开车")

 #作者名
 a1 = orm_s.Author(name="Alex")
 a2 = orm_s.Author(name="Jack")
 a3 = orm_s.Author(name="Rain")

 #关联关系
 b1.authors = [a1,a2]
 b2.authors = [a1,a2,a3]

 s.add_all([b1,b2,b3,b4,a1,a2,a3])
 '''

 '''
 #查询  作者表                   条件       作者名==alex
 aut_obj=s.query(orm_s.Author).filter(orm_s.Author.name=='Alex').first()#返回一个对象
 print(aut_obj,aut_obj.books,aut_obj.books[0])
 '''

 #更新
 s.query(orm_s.Book).filter(orm_s.Book.id ==2).update({"pub_date" : "2017-06-07"})

 #查询  书表                   条件       书id==2
 book_obj=s.query(orm_s.Book).filter(orm_s.Book.id==2).first()
 book_obj2=s.query(orm_s.Book).filter(orm_s.Book.id==1).first()
 print(book_obj.authors,book_obj)#输出书的作者  书名
 #book_obj.authors.remove(aut_obj)#删除书中的一个作者
 print(book_obj2.authors,book_obj2)#输出书的作者  书名

 #删除作者,会把这个作者跟所有书的关联关系数据也自动删除
 '''
 s.delete(aut_obj)
 '''
 book_obj=s.query(orm_s.Book).filter(orm_s.Book.id==2).first()
 book_obj2=s.query(orm_s.Book).filter(orm_s.Book.id==1).first()
 print(book_obj.authors,book_obj)#输出书的作者  书名
 print(book_obj2.authors,book_obj2)#输出书的作者  书名

 s.commit()