89 lines
2.5 KiB
Python
89 lines
2.5 KiB
Python
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from sqlalchemy import Table, Column, Integer, String, MetaData, ForeignKey, create_engine, DateTime, Boolean, or_
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from sqlalchemy.orm import sessionmaker, relationship, backref
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from sqlalchemy.ext.declarative import declarative_base
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import datetime
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engine = create_engine('sqlite:///data')
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Base = declarative_base()
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Session = sessionmaker(bind=engine)
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class User(Base):
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__tablename__ = 'users'
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name = Column(String(10), primary_key=True)
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card = Column(String(10))
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credit = Column(Integer)
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def __init__(self, name, card, credit=0):
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self.name = name
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self.card = card
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self.credit = credit
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def __repr__(self):
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return "<User('%s')>" % self.name
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class Product(Base):
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__tablename__ = 'products'
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bar_code = Column(Integer, primary_key=True)
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name = Column(String(30))
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price = Column(Integer)
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def __init__(self, bar_code, name, price):
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self.name = name
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self.bar_code = bar_code
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self.price = price
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def __repr__(self):
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return "<Product('%s', '%s', '%s')>" % (self.name, self.bar_code, self.price)
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class PurchaseEntry(Base):
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__tablename__ = 'purchase_entries'
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id = Column(Integer, primary_key=True)
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purchase_id = Column(Integer,ForeignKey("purchases.id"))
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product_bar_code = Column(Integer,ForeignKey("products.bar_code"))
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amount = Column(Integer)
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product = relationship(Product,backref="purchases")
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def __init__(self, purchase, product, amount):
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self.product = product
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self.product_bar_code = product.bar_code
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self.purchase_id = purchase.id
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self.amount = amount
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def __repr__(self):
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return "<PurchaseEntry('%s', '%s', '%s')>" % (self.purchase.user.user, self.product.name, self.amount )
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class Purchase(Base):
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__tablename__ = 'purchases'
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id = Column(Integer, primary_key=True)
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time = Column(DateTime)
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user_name = Column(Integer, ForeignKey('users.name'))
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price = Column(Integer)
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performed = Column(Boolean)
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user = relationship(User, backref=backref('purchases', order_by=id))
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products = relationship(PurchaseEntry, backref=backref("purchase"))
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def __init__(self ,performed=False):
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self.performed = performed
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def __repr__(self):
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return "<Purchase('%s', '%s', '%s')>" % (self.user.name, self.price, self.time.strftime('%c'))
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def set_price(self):
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self.price = 0
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for entry in self.products:
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self.price += entry.amount*entry.product.price
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def perform_purchase(self):
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if self.performed:
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print "This transaction has already been performed"
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else:
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self.time = datetime.datetime.now()
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self.set_price()
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self.user.credit -= self.price
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self.performed = True
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