sqlalchemy操作Mysql
作者:互联网
SQLAlchemy“采用简单的Python语言,为高效和高性能的数据库访问设计,实现了完整的企业级持久模型”。SQLAlchemy的理念是,SQL数据库的量级和性能重要于对象集合;而对象集合的抽象又重要于表和行。因此,SQLAlchmey采用了类似于Java里Hibernate的数据映射模型,而不是其他ORM框架采用的Active Record模型。不过,Elixir和declarative等可选插件可以让用户使用声明语法。
安装
pip3 install SQLAlchemy
pip3 install pymysql #需要pymysql或者MySQLdb的支持
连接数据库
mysql+pymysql://<username>:<password>@<host>/<dbname>[?<options>]
下面我们看一个例子:
#导入想关模块
from sqlalchemy import create_engine from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index from sqlalchemy.orm import sessionmaker, relationship engine = create_engine("mysql+pymysql://root:123456@192.168.11.12:3306/haha", encoding='utf-8', max_overflow=5) # DBSession = sessionmaker(bind=engine) #实例化 Base = declarative_base() # 主机表 class Host(Base): #声明类 __tablename__ = 'host' #需要创建的表名 nid = Column(Integer, primary_key=True, autoincrement=True) #定义主键,自增1 ,其实这里还可以有其他参数 hostname = Column(String(32)) ip = Column(String(32), unique=True) port = Column(String(32)) host_user = relationship('HostUser',secondary=lambda: HostToHostUser.__table__,backref='h')#映射表的外键 # 主机用户表 class HostUser(Base): __tablename__ = 'host_user' nid = Column(Integer, primary_key=True, autoincrement=True) username = Column(String(32)) passwd = Column(String(32)) # 主机用户与主机关系表 class HostToHostUser(Base): __tablename__ = 'host_to_hostuser' nid = Column(Integer, primary_key=True, autoincrement=True) user_nid = Column(Integer, ForeignKey('host_user.nid')) host_nid = Column(Integer, ForeignKey('host.nid')) host = relationship('Host', backref='h') host_user = relationship('HostUser', backref='u') # 审计表 class AuditLog(Base): __tablename__ = 'audit_log' nid = Column(Integer, primary_key=True) user_nid = Column(Integer, ForeignKey('host_user.nid')) host_nid = Column(Integer, ForeignKey('host.nid')) cmd = Column(String(255)) date = Column(String(255)) def init_db(): Base.metadata.create_all(engine) def drop_db(): Base.metadata.drop_all(engine) init_db() Session = sessionmaker(bind=engine) session = Session() # # session.add_all(( Host(hostname='web1', ip='192.168.11.12', port='22', ), Host(hostname='web2', ip='192.168.11.23', port='22', ), Host(hostname='web3', ip='192.168.11.34', port='22', ), Host(hostname='web4', ip='192.168.11.45', port='22', ), Host(hostname='web5', ip='192.168.11.228', port='22', ), )) session.commit() session.add_all([ HostUser(username='madking', passwd='123', ), HostUser(username='oldboy', passwd='123', ), ]) session.commit() session.add_all(( HostToHostUser(user_nid='1', host_nid='1', ), HostToHostUser(user_nid='1', host_nid='2', ), HostToHostUser(user_nid='1', host_nid='5', ), HostToHostUser(user_nid='2', host_nid='1', ), )) session.commit()
标签:__,sqlalchemy,Column,Integer,nid,host,user,Mysql,操作 来源: https://blog.51cto.com/slapping/2801225