学习SQLAlchemy Core

有时间了就要慢慢看，死守DJANGO ORM，明显没有SQLAlchemy有优势。

因为SQLAlchemy针对整个PYTHON都是有用的。

找了本书，慢慢撸。

《Essential.SQLAlchemy.2nd.Edition》

创建数据库的代码：

#coding=utf-8

from datetime import datetime
from sqlalchemy import (MetaData, Table, Column, Integer, Numeric, String, Boolean,
                        DateTime, ForeignKey, ForeignKey, create_engine)

metadata = MetaData()

cookies = Table('cookies', metadata,
                Column('cookie_id', Integer(), primary_key=True),
                Column('cookie_name', String(50), index=True),
                Column('cookie_recipe_url', String(255)),
                Column('cookie_sku', String(55)),
                Column('quantity', Integer()),
                Column('unit_cost', Numeric(12, 2))
                )

users = Table('users', metadata,
              Column('user_id', Integer(), primary_key=True),
              Column('username', String(15), nullable=False, unique=True),
              Column('email_address', String(255), nullable=False),
              Column('phone', String(20), nullable=False),
              Column('password' ,String(25), nullable=False),
              Column('created_on', DateTime(), default=datetime.now),
              Column('updated_on', DateTime(), default=datetime.now, onupdate=datetime.now)
              )

orders = Table('orders', metadata,
               Column('order_id', Integer(), primary_key=True),
               Column('user_id', ForeignKey('users.user_id')),
               Column('shipped', Boolean(), default=False)
               )

line_items = Table('line_items', metadata,
                   Column('line_items_id', Integer(), primary_key=True),
                   Column('order_id', ForeignKey('orders.order_id')),
                   Column('cookie_id', ForeignKey('cookies.cookie_id')),
                   Column('quantity', Integer()),
                   Column('extended_cost', Numeric(12, 2))
                   )

engine = create_engine('mysql+pymysql://user:password@1.2.7.9:3306/cookies')
metadata.create_all(engine)