dibbler/db.py

89 lines
2.5 KiB
Python

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