使用sqlalchemy

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column,Integer,String,CHAR,and_,or_,ForeignKey,UniqueConstraint,Index
from  sqlalchemy.orm import sessionmaker,relationship

engine = create_engine('mysql+pymysql://root@127.0.0.1:3306/ces?charset=utf8') #连接数据库
Base = declarative_base()#生成一个SQLORM基类

class User(Base):
     __tablename__ = 'users'
     id = Column(Integer,primary_key=True,autoincrement=True)
     name = Column(String(32))
     fullname = Column(String(32))
     password = Column(CHAR(32))
    extra = Column(String(16))
    
     __table_args__ = (
         UniqueConstraint('id', 'name', name='uix_id_name'),
         Index('ix_id_name', 'name', 'extra'),
     )

    def __repr__(self):
         return "<User(name='%s',fullname='%s',password='%s')>%(self.name,self.fullname,self.passwpord)"

一对多

class Favor(Base):
    __tablename__ = 'favor'
    nid = Column(Integer,primary_key=True,autoincrement=True)
    caption = Column(String(50),default="red",unique=True)

class Person(Base):
    __tablename__ = 'person'
    nid = Column(Integer,primary_key=True,autoincrement=True)
    name = Column(String(50),index=True,nullable=True)
    favor_id = Column(Integer,ForeignKey('favor.nid'))

多对多

class Group(Base):
    __tablename__ = 'group'
    id = Column(Integer,primary_key=True)
    name = Column(String(64),unique=True,nullable=False)
    port = Column(Integer,default=22)

class Server(Base):
    __tablename__ = 'server'
    id = Column(Integer,primary_key=True,autoincrement=True)
    hostname = Column(String(64),unique=True,nullable=False)

class ServerToGroup(Base):
    __tablename__ = 'servertogroup'
    nid = Column(Integer,primary_key=True,autoincrement=True)
    server_id = Column(Integer,ForeignKey('server.id'))
    group_id = Column(Integer,ForeignKey('group.id'))
class Son(Base):
    __tablename__ = 'son'
    id = Column(Integer,primary_key=True,autoincrement=True)
    name = Column(String(50))
    age = Column(String(16))
    father_id = Column(Integer,ForeignKey('father.id'))

class Father(Base):
    __tablename__ = 'father'
    id = Column(Integer,primary_key=True,autoincrement=True)
    name = Column(String(50))
    age = Column(String(12))
    son = relationship('Son',backref="father")

添加数据

Base.metadata.create_all(engine) #创建所有表结构
MySession = sessionmaker(bind=engine)
session = MySession()
ed_user = User(name="xiaoyu",fullname="Xiaoyu Lu",password="123")
session.add(ed_user ) 添加一条数据
session.commit()

session.add_all([
     User(name="张三",fullname="3",password="456"),
     User(name="王五",fullname="5",password="789"),
     User(name="马六",fullname="6",password="sxsxsx")
])#添加多条数据

session.commit()

session.close()

删除数据

 1 session.query(Users).filter(Users.id > 2).delete() 

修改数据

#把ID大于2的名字都改为099
session.query(Users).filter(Users.id > 2).update({"name" : "099"})
#把ID大于2的名字，在原有的名字基础上加099
session.query(Users).filter(Users.id > 2).update({Users.name: Users.name + "099"}, synchronize_session=False)
#把ID大于2的数值都加1
session.query(Users).filter(Users.id > 2).update({"num": Users.num + 1}, synchronize_session="evaluate")
session.commit()

查询数据

#排序，从小到大读取数据
for row in session.query(User).order_by(User.id):
     print(row)
#按条件查询查询（查询数据库中在列表里面是否有相同的内容，如果有就打印，没有则不打印）
for row in session.query(User).filter(User.name.in_(['wangwu','zhansgan','jack'])):
     print(row)
#按条件查询查询，与上面的刚好相反，如果存在不打印，不存在打印
 for row in session.query(User).filter(~User.name.in_(['wangwu','zhansgan','jack'])):
     print(row)
#统计有多少条内
session.query(User).filter(User.name == 'wangwu').count()
session.query(User).filter_by(id=1).count()

#读取多条
ret = session.query(Users).filter_by(name='wangwu').all()
#读取一条
ret = session.query(Users).filter_by(name='wangwu').first()

ret = session.query(Users).filter(text("id<:value and name=:name")).params(value=224, name='fred').order_by(User.id).all()

ret = session.query(Users).from_statement(text("SELECT * FROM users where name=:name")).params(name='ed').all()

其他

#　条件
ret = session.query(Users).filter_by(name='alex').all()
ret = session.query(Users).filter(Users.id > 1, Users.name == 'eric').all()
ret = session.query(Users).filter(Users.id.between(1, 3), Users.name == 'eric').all()
ret = session.query(Users).filter(Users.id.in_([1,3,4])).all()
ret = session.query(Users).filter(~Users.id.in_([1,3,4])).all()
ret = session.query(Users).filter(Users.id.in_(session.query(Users.id).filter_by(name='eric'))).all()
from sqlalchemy import and_, or_
ret = session.query(Users).filter(and_(Users.id > 3, Users.name == 'eric')).all()
ret = session.query(Users).filter(or_(Users.id < 2, Users.name == 'eric')).all()
ret = session.query(Users).filter(
    or_(
        Users.id < 2,
        and_(Users.name == 'eric', Users.id > 3),
        Users.extra != ""
    )).all()


# 通配符
ret = session.query(Users).filter(Users.name.like('e%')).all()
ret = session.query(Users).filter(~Users.name.like('e%')).all()

# 限制
ret = session.query(Users)[1:2]

# 排序
ret = session.query(Users).order_by(Users.name.desc()).all()
ret = session.query(Users).order_by(Users.name.desc(), Users.id.asc()).all()

# 分组
from sqlalchemy.sql import func

ret = session.query(Users).group_by(Users.extra).all()
ret = session.query(
    func.max(Users.id),
    func.sum(Users.id),
    func.min(Users.id)).group_by(Users.name).all()

ret = session.query(
    func.max(Users.id),
    func.sum(Users.id),
    func.min(Users.id)).group_by(Users.name).having(func.min(Users.id) >2).all()

# 连表

ret = session.query(Users, Favor).filter(Users.id == Favor.nid).all()

ret = session.query(Person).join(Favor).all()

ret = session.query(Person).join(Favor, isouter=True).all()


# 组合
q1 = session.query(Users.name).filter(Users.id > 2)
q2 = session.query(Favor.caption).filter(Favor.nid < 2)
ret = q1.union(q2).all()

q1 = session.query(Users.name).filter(Users.id > 2)
q2 = session.query(Favor.caption).filter(Favor.nid < 2)
ret = q1.union_all(q2).all()