Day13 SQLAlchemy连表操作和堡垒机

1、创建表、插入数据和一对多查询

#！/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: wanghuafeng

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

engine = create_engine("mysql+pymysql://root:[email protected]:3306/s13", max_overflow =5)
Base = declarative_base()

#单表
class Test(Base):
    __tablename__ = ‘test‘
    nid = Column(Integer, primary_key=True, autoincrement=True)
    name = Column(String(32))

#一对多
class Group(Base):
    __tablename__ = ‘group‘
    nid = Column(Integer, primary_key=True, autoincrement=True)
    caption = Column(String(32))

class User(Base):
    __tablename__ = ‘user‘
    nid = Column(Integer, primary_key=True, autoincrement=True)
    username = Column(String(32))
    #外键
    group_id = Column(Integer, ForeignKey("group.nid"))
    # 只用于查询
    #uuu代表虚拟列：[1 wang, 3 xiaoming, 4 xiaoxiao]
    #relationship与ForeignKey一般在一起
    group = relationship("Group", backref=‘uuu‘)

    #只是对print对象的时候有用
    def __repr__(self):
        #return "<nid=%s, username=%s, group_id=%s>" % (self.nid, self.username, self.group_id)
        temp = "%s - %s - %s" % (self.nid, self.username, self.group_id)
        return temp

#创建表
def init_db():
    Base.metadata.create_all(engine)

def drop_db():
    Base.metadata.drop_all(engine)

init_db()
#创建组
Session = sessionmaker(bind=engine)
session = Session()
session.add(Group(caption = ‘dba‘))
session.add(Group(caption = ‘dbd‘))
session.commit()

#只获取用户
ret = session.query(User).filter(User.username==‘wang‘).all()
print(ret)

ret = session.query(User).all()
obj = ret[0]
print(obj)
print(obj.nid)
print(obj.username)
print(obj.group_id)
ret = session.query(User.username).all()
print(ret)

#左连接isouter=True
#同时取两个表session.query(User, Group)
sql = session.query(User, Group).join(Group, isouter=True)
sql = session.query(User.username, Group.caption).join(Group, isouter=True)
print(sql)
ret = session.query(User.username, Group.caption).join(Group, isouter=True).all()
#select * from user left join group on user.group_id = group.nid
print(ret)

#新方式（正向查询）:relationship在这个表里并查询该表的数据
ret = session.query(User).all()
for obj in ret:
    # obj.group：obj代表user表的每一行数据
    # obj.group为group对象
    print(obj.nid, obj.username, obj.group_id, obj.group, obj.group.nid, obj.group.caption)

#列出组中的所有人
# ret = session.query(User.username, Group.caption).join(Group, isouter=True).filter(Group.caption == ‘dba‘).all()
# print(ret)
#新方式（反向查询）：relationship不在这个表里并查询其他表的数据
obj = session.query(Group).filter(Group.caption == ‘dba‘).first()
print(obj.nid, obj.caption)
print(obj.uuu)

2、多对多关联

#！/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: wanghuafeng

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

engine = create_engine("mysql+pymysql://root:[email protected]:3306/s13", max_overflow =5)
Base = declarative_base()

#多对多
class Host(Base):
    __tablename__ = ‘host‘
    nid = Column(Integer, primary_key=True, autoincrement=True)
    hostname = Column(String(32))
    port = Column(String(32))
    ip = Column(String(32))

class HostUser(Base):
    __tablename__ = ‘host_user‘
    nid = Column(Integer, primary_key=True, autoincrement=True)
    username = Column(String(32))

class HostToHostUser(Base):
    __tablename__ = ‘host_to_hostuser‘
    #增加nid，方便以后删除
    nid = Column(Integer, primary_key=True, autoincrement=True)
    host_id = Column(Integer, ForeignKey(‘host.nid‘))
    host_user_id = Column(Integer, ForeignKey(‘host_user.nid‘))

#创建表
def init_db():
    Base.metadata.create_all(engine)

def drop_db():
    Base.metadata.drop_all(engine)

init_db()

Session = sessionmaker(bind=engine)
session = Session()

#循环插入数据
session.add_all([
    Host(hostname=‘c1‘, port=‘22‘, ip=‘1.2.1.2‘),
    Host(hostname=‘c2‘, port=‘22‘, ip=‘1.2.1.3‘),
    Host(hostname=‘c3‘, port=‘22‘, ip=‘1.2.1.1‘),
    Host(hostname=‘c4‘, port=‘22‘, ip=‘1.2.1.4‘),
    Host(hostname=‘c5‘, port=‘22‘, ip=‘1.2.1.5‘),
])
session.commit()

session.add_all([
    HostUser(username=‘root‘),
    HostUser(username=‘mysql‘),
    HostUser(username=‘svn‘),
    HostUser(username=‘git‘),
    HostUser(username=‘oracle‘),
])
session.commit()

session.add_all([
    HostToHostUser(host_id=‘1‘, host_user_id=1),
    HostToHostUser(host_id=‘1‘, host_user_id=2),
    HostToHostUser(host_id=‘1‘, host_user_id=3),
    HostToHostUser(host_id=‘2‘, host_user_id=4),
    HostToHostUser(host_id=‘2‘, host_user_id=5),
    HostToHostUser(host_id=‘2‘, host_user_id=1),
    HostToHostUser(host_id=‘3‘, host_user_id=1),
    HostToHostUser(host_id=‘3‘, host_user_id=2),
    HostToHostUser(host_id=‘3‘, host_user_id=3),
    HostToHostUser(host_id=‘4‘, host_user_id=4),
    HostToHostUser(host_id=‘4‘, host_user_id=5),
    HostToHostUser(host_id=‘4‘, host_user_id=1),
    HostToHostUser(host_id=‘5‘, host_user_id=4),
    HostToHostUser(host_id=‘5‘, host_user_id=5),
    HostToHostUser(host_id=‘5‘, host_user_id=1),
])
session.commit()

#多对多操作数据

#获取主机1中的所有用户
host_obj = session.query(Host).filter(Host.hostname == ‘c1‘).first()
#host_obj.nid(找到主机id)

host_2_host_user = session.query(HostToHostUser.host_user_id).filter(HostToHostUser.host_id == host_obj.nid).all()
print(host_2_host_user)
#[(1,), (2,), (3,)]
r = zip(*host_2_host_user)
#print(list(r)[0])

#[1, 2, 3]
users = session.query(HostUser.username).filter(HostUser.nid.in_(list(r)[0])).all()
print(users)

3、多对多查询最简单方式

#！/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: wanghuafeng

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

engine = create_engine("mysql+pymysql://root:[email protected]:3306/s13", max_overflow =5)
Base = declarative_base()

#多对多
class Host(Base):
    __tablename__ = ‘host‘
    nid = Column(Integer, primary_key=True, autoincrement=True)
    hostname = Column(String(32))
    port = Column(String(32))
    ip = Column(String(32))

class HostUser(Base):
    __tablename__ = ‘host_user‘
    nid = Column(Integer, primary_key=True, autoincrement=True)
    username = Column(String(32))

class HostToHostUser(Base):
    __tablename__ = ‘host_to_hostuser‘
    #增加nid，方便以后删除
    nid = Column(Integer, primary_key=True, autoincrement=True)
    host_id = Column(Integer, ForeignKey(‘host.nid‘))
    host_user_id = Column(Integer, ForeignKey(‘host_user.nid‘))

    host = relationship("Host", backref=‘h‘)
    host_user = relationship("HostUser", backref=‘u‘)

Session = sessionmaker(bind=engine)
session = Session()

#获取主机1中的所有用户
#主机
host_obj = session.query(Host).filter(Host.hostname==‘c1‘).first()
#host_to_hostuser表中的对象
#print(host_obj.h)

for item in host_obj.h:
    print(item.host_user, item.host_user.nid, item.host_user.username)