day13 SQLAlchemy

MySQL-Python
    mysql+mysqldb://<user>:<password>@<host>[:<port>]/<dbname>
   
pymysql
    mysql+pymysql://<username>:<password>@<host>/<dbname>[?<options>]
   
MySQL-Connector
    mysql+mysqlconnector://<user>:<password>@<host>[:<port>]/<dbname>
   
cx_Oracle
    oracle+cx_oracle://user:pass@host:port/dbname[?key=value&key=value...]
   
更多详见：http://docs.sqlalchemy.org/en/latest/dialects/index.html

#!/usr/bin/env python
# -*- coding:utf-8 -*-
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:123456@10.70.18.100:3306/ttt",max_overflow=5)    #连接数据库
Base = declarative_base()
#创建单表：
class Users(Base):     #类必须要继承Base
    __tablename__ = ‘users‘     #表名
    id = Column(Integer,primary_key=True)    #创建列
    name = Column(String(32))
    extra = Column(String(16))
    __table_args__ = (
        UniqueConstraint(‘id‘,‘name‘,name=‘centos‘),     #联合索引
        Index(‘ix_id_name‘,‘name‘,‘extra‘),
    )

#一对多
class Favor(Base):
    __tablename__ = ‘favor‘
    nid = Column(Integer,primary_key=True)
    caption = Column(String(50),default=‘red‘,unique=True)
class Person(Base):
    __tablename__ = ‘person‘
    nid = Column(Integer,primary_key=True)
    name = Column(String(32),index=True,nullable=True)
    favor_id = Column(Integer,ForeignKey("favor.nid"))     #根上一个favor的nid做外键
#多对多
class ServerToGroup(Base):
    __tablename__ = ‘servertogroup‘
    id = Column(Integer,primary_key=True,autoincrement=True)
    hostname = Column(String(64),unique=True,nullable=False)

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

class Server(Base):
    __tablename__ = ‘server‘
    id = Column(Integer,primary_key=True,autoincrement=True)
    hostname = Column(String(64),unique=True,nullable=False)
    port = Column(Integer,default=22)

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

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

drop_db()    #删除