+### Database Schemas ###
+
+users = sa.Table('users', meta.metadata,
+ sa.Column('id', sa.types.Integer, primary_key=True),
+ sa.Column('username', sa.types.Unicode(32), nullable=False),
+ sa.Column('name', sa.types.Unicode(64)),
+ sa.Column('resident', sa.types.Boolean, default=True)
+ )
+
+expenditures = sa.Table('expenditures', meta.metadata,
+ sa.Column('id', sa.types.Integer, primary_key=True),
+ sa.Column('spender_id', sa.types.Integer,
+ sa.ForeignKey('users.id'), nullable=False),
+ sa.Column('amount', types.Currency, nullable=False),
+ sa.Column('description', sa.types.Text),
+ sa.Column('date', sa.types.Date, default=datetime.now),
+ sa.Column('entered_time', sa.types.DateTime,
+ default=datetime.now)
+ )
+
+splits = sa.Table('splits', meta.metadata,
+ sa.Column('id', sa.types.Integer, primary_key=True),
+ sa.Column('expenditure_id', sa.types.Integer,
+ sa.ForeignKey('expenditures.id'), nullable=False),
+ sa.Column('user_id', sa.types.Integer,
+ sa.ForeignKey('users.id'), nullable=False),
+ sa.Column('share', types.Currency, nullable=False)
+ )
+
+subitems = sa.Table('subitems', meta.metadata,
+ sa.Column('id', sa.types.Integer, primary_key=True),
+ sa.Column('expenditure_id', sa.types.Integer,
+ sa.ForeignKey('expenditures.id'), nullable=False),
+ sa.Column('user_id', sa.types.Integer,
+ sa.ForeignKey('users.id'), nullable=False),
+ sa.Column('amount', types.Currency, nullable=False)
+ )
+
+transfers = sa.Table('transfers', meta.metadata,
+ sa.Column('id', sa.types.Integer, primary_key=True),
+ sa.Column('debtor_id', sa.types.Integer,
+ sa.ForeignKey('users.id'), nullable=False),
+ sa.Column('creditor_id', sa.types.Integer,
+ sa.ForeignKey('users.id'), nullable=False),
+ sa.Column('amount', types.Currency, nullable=False),
+ sa.Column('description', sa.Text, default=None),
+ sa.Column('date', sa.types.Date, default=datetime.now),
+ sa.Column('entered_time', sa.types.DateTime,
+ default=datetime.now)
+ )
+
+### ORM Classes ###
+
+class User(object):
+ def __repr__(self):
+ return '<User: %s>' % (self.username)
+
+class Expenditure(object):
+ def __repr__(self):
+ return '<Expenditure: spender: %s spent: %s>' % (self.spender,
+ self.amount)
+
+class Split(object):
+ def __repr__(self):
+ return '<Split: expense: %s user: %s share: %s>' % (self.expenditure,
+ self.user,
+ self.share)
+
+class Subitem(object):
+ def __repr__(self):
+ return '<Subitem: expense: %s user: %s cost: %s>' % (self.expense,
+ self.user,
+ self.amount)
+
+class Transfer(object):
+ def __repr__(self):
+ return '<Transfer: from %s to %s for %s>' % (self.debtor,
+ self.creditor,
+ self.amount)
+
+### DB/Class Mapping ###
+
+orm.mapper(User, users)
+
+orm.mapper(Expenditure, expenditures, properties={
+ 'spender': orm.relation(User, backref='expenditures')
+})
+
+orm.mapper(Split, splits, properties={
+ 'expenditure': orm.relation(Expenditure, backref='splits'),
+ 'user': orm.relation(User)
+})
+
+orm.mapper(Subitem, subitems, properties={
+ 'expenditure': orm.relation(Expenditure, backref='subitems'),
+ 'user': orm.relation(User)
+})
+
+orm.mapper(Transfer, transfers, properties={
+ 'debtor': orm.relation(User,
+ primaryjoin=(transfers.c.debtor_id==\
+ users.c.id)),
+ 'creditor': orm.relation(User,
+ primaryjoin=(transfers.c.creditor_id==\
+ users.c.id))
+})