minecraft recipe sql test

recipedb.py

from sqlalchemy import (
    create_engine,
    Index,
    Column,
    ForeignKey,
    Integer,
    String,
    Table,
    )

from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy.orm import (
    scoped_session,
    sessionmaker,
    relationship,
    )

engine = create_engine('sqlite://')
session = scoped_session(sessionmaker())
session.configure(bind=engine)

Base = declarative_base()

before_association = Table('before_association', Base.metadata,
                           Column('item_id', Integer, ForeignKey('items.id')),
                           Column('recipe_id', Integer, ForeignKey('recipes.id')),
)

after_association = Table('after_association', Base.metadata,
                          Column('recipe_id', Integer, ForeignKey('recipes.id')),
                          Column('item_id', Integer, ForeignKey('items.id')),
)

class Item(Base):
    __tablename__ = 'items'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    def __init__(self, name):
        self.name = name

    def __repr__(self):
        return "<Item object name:%s>"%self.name


class Recipe(Base):
    __tablename__ = 'recipes'
    id = Column(Integer, primary_key=True)
    outputs = relationship('Item', secondary=after_association, backref='out_recipes')
    materials = relationship('Item', secondary=before_association, backref='in_recipes')


Base.metadata.create_all(engine)

cobblestone = Item('cobblestone')