python第六十六天--sqlalchemy

 1 #!usr/bin/env python
 2 #-*-coding:utf-8-*-
 3 # Author calmyan 
 4 #python 
 5 #2017/7/6    21:29
 6 #__author__='Administrator'
 7 from sqlalchemy.ext.declarative import declarative_base
 8 from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
 9 from sqlalchemy.orm import sessionmaker, relationship
10 from sqlalchemy import create_engine
11 from sqlalchemy import func #统计
12 
13 #                                         用户 密码  主机             库
14 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test",encoding="utf-8",echo=False)
15 
16 Base = declarative_base()#生成orm 基类
17 class User_2(Base):
18     __tablename__='user' #表名
19     id = Column(Integer,primary_key=True)#整数类型  设为主键
20     name = Column(String(32))#字符串类型
21     age = Column(Integer)
22     addr= Column(String(256))
23 
24     def __repr__(self):#输出查询
25         return '%s>name:%s--age:%saddrs:%s'%(self.id,self.name,self.age,self.addr)
26 
27 
28 Session_class=sessionmaker(bind=engine)#创建与数据库的会话 类
29 Session=Session_class()#生成实例
30 
31 #增加
32 '''
33 user_obj =User(name="sa2",addrs="1234")#生成你要创建的数据对象
34 Session.add(user_obj)# 添加记录
35 '''
36 #添加一组数据
37 '''
38 Session.add_all([
39     User(name="abcg",age=34,addr="sdfsdf"),
40     User(name="bcdq",age=11,addr="chaense")
41 ])
42 '''
43 #删除
44 '''
45 Session.query(User).filter(User.id>3).filter(User.id<6).delete()
46 '''
47 #              查询        条件            所有
48 data =Session.query(User_2).filter_by(id=2).all()
49 #                                 多个条件
50 data2 =Session.query(User_2).filter(User_2.id>2).filter(User_2.id<5).all()
51 
52 
53 #改
54 
55 Session.query(User_2).filter(User_2.id ==2).update({"name" : "099"})
56 print(data)
57 print(data2)
58 '''
59 print(Session.query(User).filter(User.id>2).filter(User.name.in_(["sa",'sa2'])).all())
60 Session.rollback()#回滚操作
61 print(Session.query(User).filter(User.id>2).filter(User.name.in_(["sa",'sa2'])).all())
62 '''
63 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
64 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
65 print(counts)
66 #分组查询              字段        统计次数                  字段
67 gurps=Session.query(User_2.name,func.count(User_2.name)).group_by(User_2.name).all()
68 print(gurps)
69 #                                                              以addrs为条件
70 gurps1=Session.query(User_2.name,func.count(User_2.name)).group_by(User_2.addr).all()
71 print(gurps1)
72 
73 
74 Session.commit()#关闭事务

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sqlalchemy 基本操作

 1 from sqlalchemy.ext.declarative import declarative_base
 2 from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index
 3 from sqlalchemy.orm import sessionmaker, relationship
 4 from sqlalchemy import create_engine
 5 #                                         用户 密码  主机             库
 6 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test",encoding="utf-8",echo=True)
 7 
 8 Base = declarative_base()#生成orm 基类
 9 class User(Base):
10     __tablename__='info_l' #表名
11     id = Column(Integer,primary_key=True)#整数类型  设为主键
12     name = Column(String(32))#字符串类型
13     addrs= Column(String(256))
14 
15 Base.metadata.create_all(engine)#创建表结构
16 
17 Session_class=sessionmaker(bind=engine)#创建与数据库的会话 类
18 Session=Session_class()#生成实例
19 
20 user_obj =User(name="sa",addrs="1234")#生成你要创建的数据对象
21 print(user_obj.name,user_obj.addrs)#此时并未创建对象
22 Session.add(user_obj)#开启事务进行连接 添加记录
23 Session.commit()#关闭事务

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外键操作示例

 1 #!usr/bin/env python
 2 #-*-coding:utf-8-*-
 3 # Author calmyan 
 4 #python 
 5 #2017/7/7    10:28
 6 #__author__='Administrator'
 7 import sqlalchemy
 8 from sqlalchemy.ext.declarative import declarative_base
 9 from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index,DATE
10 from sqlalchemy.orm import sessionmaker, relationship
11 from sqlalchemy import create_engine
12 #                                         用户 密码  主机             库
13 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test",encoding="utf-8",echo=False)
14 
15 Base = declarative_base()#生成orm 基类
16 
17 class Studes(Base):#学生类
18     __tablename__ ='studes'
19     id = Column(Integer,primary_key=True)#整数类型  设为主键
20     name = Column(String(32),nullable=False)#字符串类型 不能为空
21     register_day= Column(DATE,nullable=False)#日期
22 
23     def __repr__(self):#输出查询
24         return '%s>name:%s--register_day :%s'%(self.id,self.name,self.register_day)
25 
26 
27 class Studes_Cr(Base):#课程类
28     __tablename__ ='stud_cr'
29     id = Column(Integer,primary_key=True)#整数类型  设为主键
30     day= Column(Integer,nullable=False)
31     status= Column(String(35),nullable=False)#上课记录
32     stu_id= Column(Integer,ForeignKey("studes.id",))#外键关联
33     studes=relationship("Studes",backref="m_study_reg")#自定义关联反查
34 
35     def __repr__(self):#输出查询         自定义 外键关联调用
36         return '%s>day:%s  status:%s'%(self.studes.name,self.day,self.status)
37 
38 Base.metadata.create_all(engine)#创建表结构
39 
40 Session_class=sessionmaker(bind=engine)#创建与数据库的会话 类
41 Session=Session_class()#生成实例
42 
43 '''
44 s1 = Studes(name="Alex",register_day='2017-05-06')#学生
45 s2 = Studes(name="bolg",register_day='2017-03-06')
46 s3 = Studes(name="calm",register_day='2017-01-07')
47 s4 = Studes(name="Defr",register_day='2017-03-16')
48 s5 = Studes(name="Eale",register_day='2017-02-24')
49 
50 study_obj1=Studes_Cr(day=1,status="YES",stu_id=1)#上课记录
51 study_obj2=Studes_Cr(day=1,status="YES",stu_id=2)#上课记录
52 study_obj3=Studes_Cr(day=1,status="NO",stu_id=3)#上课记录
53 study_obj4=Studes_Cr(day=1,status="YES",stu_id=4)#上课记录
54 study_obj5=Studes_Cr(day=2,status="NO",stu_id=1)#上课记录
55 study_obj6=Studes_Cr(day=2,status="YES",stu_id=2)#上课记录
56 study_obj7=Studes_Cr(day=2,status="YES",stu_id=3)#上课记录
57 
58 #一次全部添加
59 Session.add_all([s1,s2,s3,s4,s5,study_obj1,study_obj2,study_obj3,study_obj4,study_obj5,study_obj6,study_obj7])
60 '''
61 
62 
63 #查询 学生对应的信息
64 stu_obj= Session.query(Studes).filter(Studes.name=="Alex").first()
65 print(stu_obj)
66 #通过外键进行相关信息查询
67 print(stu_obj.m_study_reg)
68 
69 Session.commit()

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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

 1 #!usr/bin/env python
 2 #-*-coding:utf-8-*-
 3 # Author calmyan 
 4 #python 
 5 #2017/7/7    13:06
 6 #__author__='Administrator'
 7 
 8 from sqlalchemy import Integer, ForeignKey, String, Column
 9 from sqlalchemy.ext.declarative import declarative_base
10 from sqlalchemy.orm import relationship
11 from sqlalchemy import create_engine
12 
13 Base = declarative_base()#生成orm 基类
14 class Customer(Base):
15     __tablename__ = 'customer'
16     id = Column(Integer, primary_key=True)
17     name = Column(String(32),nullable=False)
18 
19     billing_address_id = Column(Integer, ForeignKey("address.id"))#帐单地址外键关联
20     shipping_address_id = Column(Integer, ForeignKey("address.id"))#收货地址外键关联
21 
22     billing_address = relationship("Address",foreign_keys=[billing_address_id])#帐单地址自定义反查 对应外键
23     shipping_address = relationship("Address",foreign_keys=[shipping_address_id])#收货地址
24 
25 class Address(Base):
26     __tablename__ = 'address'
27     id = Column(Integer, primary_key=True)
28     street = Column(String(32))#详细
29     city = Column(String(32))#市
30     state = Column(String(255))#省
31 
32     def __repr__(self):
33         return self.state+self.city+self.street
34 
35 #                                         用户 密码  主机             库
36 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test",encoding="utf-8",echo=False)
37 
38 
39 Base.metadata.create_all(engine)#创建表结构

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多外键_操作.py

 

 1 #!usr/bin/env python
 2 #-*-coding:utf-8-*-
 3 # Author calmyan 
 4 #python 
 5 #2017/7/7    13:21
 6 #__author__='Administrator'
 7 import os ,sys
 8 from day66 import 多外键关联
 9 from sqlalchemy.orm import relationship,sessionmaker
10 from sqlalchemy import create_engine
11 Session_class=sessionmaker(bind=多外键关联.engine)#创建与数据库的会话 类
12 Session=Session_class()#生成实例
13 '''
14 addr1=多外键关联.Address(street="btxw",city='xy',state="fj")
15 addr2=多外键关联.Address(street="jjqy",city='qz',state="fj")
16 addr3=多外键关联.Address(street="ml",city='pt',state="fj")
17 
18 Session.add_all([addr1,addr2,addr3])#写入数据库
19 
20 c1=多外键关联.Customer(name='calmyan',billing_address=addr1,shipping_address=addr1)
21 c2=多外键关联.Customer(name='alex',billing_address=addr3,shipping_address=addr2)
22 Session.add_all([c1,c2])
23 '''
24 
25 #查询
26 sobj=Session.query(多外键关联.Customer).filter(多外键关联.Customer.name=='calmyan').first()
27 
28 print(sobj.name,sobj.billing_address,sobj.shipping_address)
29 
30 Session.commit()

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多对多外键示例:

orm_s.py

 1 #!usr/bin/env python
 2 #-*-coding:utf-8-*-
 3 # Author calmyan 
 4 #python 
 5 #2017/7/7    14:07
 6 #__author__='Administrator'
 7 
 8 #一本书可以有多个作者，一个作者又可以出版多本书
 9 
10 
11 from sqlalchemy import Table, Column, Integer,String,DATE, ForeignKey
12 from sqlalchemy.orm import relationship
13 from sqlalchemy.ext.declarative import declarative_base
14 from sqlalchemy import create_engine
15 from sqlalchemy.orm import sessionmaker
16 
17 Base = declarative_base()
18 
19 #创建第三张表,自动维护
20 book_m2m_author = Table('book_m2m_author', Base.metadata,
21                         Column('book_id',Integer,ForeignKey('books.id')),#关联外键,书id
22                         Column('author_id',Integer,ForeignKey('authors.id')),#关联外键,作者id
23                         )
24 
25 class Book(Base):#书名
26     __tablename__ = 'books'
27     id = Column(Integer,primary_key=True)
28     name = Column(String(64))
29     pub_date = Column(DATE)
30     authors = relationship('Author',secondary=book_m2m_author,backref='books')
31 
32     def __repr__(self):
33         return self.name
34 
35 class Author(Base):#作者
36     __tablename__ = 'authors'
37     id = Column(Integer, primary_key=True)
38     name = Column(String(32))
39 
40     def __repr__(self):
41         return self.name
42 
43 #                                         用户 密码  主机             库
44 engine = create_engine("mysql+pymysql://root:root@127.0.0.1:3306/test?charset=utf8",encoding="utf-8",echo=False)
45 
46 
47 Base.metadata.create_all(engine)#创建表结构

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orm_s_aut.py

 1 #!usr/bin/env python
 2 #-*-coding:utf-8-*-
 3 # Author calmyan 
 4 #python 
 5 #2017/7/7    14:38
 6 #__author__='Administrator'
 7 
 8 from  day66 import orm_s
 9 from sqlalchemy.orm import relationship,sessionmaker
10 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
11 s = Session_class() #生成session实例
12 '''
13 #book名
14 b1 = orm_s.Book(name="跟Alex学Python")
15 b2 = orm_s.Book(name="跟Alex学把妹")
16 b3 = orm_s.Book(name="跟Alex学装逼")
17 b4 = orm_s.Book(name="跟Alex学开车")
18 
19 #作者名
20 a1 = orm_s.Author(name="Alex")
21 a2 = orm_s.Author(name="Jack")
22 a3 = orm_s.Author(name="Rain")
23 
24 #关联关系
25 b1.authors = [a1,a2]
26 b2.authors = [a1,a2,a3]
27 
28 s.add_all([b1,b2,b3,b4,a1,a2,a3])
29 '''
30 
31 
32 '''
33 #查询  作者表                   条件       作者名==alex
34 aut_obj=s.query(orm_s.Author).filter(orm_s.Author.name=='Alex').first()#返回一个对象
35 print(aut_obj,aut_obj.books,aut_obj.books[0])
36 '''
37 
38 #更新
39 s.query(orm_s.Book).filter(orm_s.Book.id ==2).update({"pub_date" : "2017-06-07"})
40 
41 #查询  书表                   条件       书id==2
42 book_obj=s.query(orm_s.Book).filter(orm_s.Book.id==2).first()
43 book_obj2=s.query(orm_s.Book).filter(orm_s.Book.id==1).first()
44 print(book_obj.authors,book_obj)#输出书的作者  书名
45 #book_obj.authors.remove(aut_obj)#删除书中的一个作者
46 print(book_obj2.authors,book_obj2)#输出书的作者  书名
47 
48 #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
49 '''
50 s.delete(aut_obj)
51 '''
52 book_obj=s.query(orm_s.Book).filter(orm_s.Book.id==2).first()
53 book_obj2=s.query(orm_s.Book).filter(orm_s.Book.id==1).first()
54 print(book_obj.authors,book_obj)#输出书的作者  书名
55 print(book_obj2.authors,book_obj2)#输出书的作者  书名
56 
57 
58 s.commit()

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