+### 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),
+ sa.Column('email', sa.types.Unicode(64)),
+ sa.Column('password', sa.types.Unicode(64)),
+ )
+
+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.DBCurrency, 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.utcnow)
+ )
+
+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_text', sa.Text, nullable=False),
+ sa.Column('share', types.DBCurrency, nullable=False)
+ )
+
+tags = sa.Table('tags', meta.metadata,
+ sa.Column('id', sa.types.Integer, primary_key=True),
+ sa.Column('name', sa.Text))
+
+tag_to_expense_map = sa.Table('tag_to_expense_map', meta.metadata,
+ sa.Column('tag_id', sa.types.Integer,
+ sa.ForeignKey('tags.id'),
+ primary_key=True),
+ sa.Column('expenditure_id', sa.types.Integer,
+ sa.ForeignKey('expenditures.id'),
+ primary_key=True))
+
+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.DBCurrency, 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.DBCurrency, 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.utcnow)
+ )
+
+### DB/Class Mapping ###
+
+orm.mapper(User, users,
+ properties={
+ 'expenditures': orm.relation(Expenditure,
+ backref='spender')
+})
+
+orm.mapper(Expenditure, expenditures,
+ order_by=[expenditures.c.date.desc(), expenditures.c.entered_time.desc()],
+ properties={
+ 'splits': orm.relation(Split, backref='expenditure',
+ cascade='all, delete'),
+ '_tags': orm.relation(Tag, secondary=tag_to_expense_map,
+ collection_class=set, cascade='all, delete'),
+ 'subitems': orm.relation(Subitem, backref='expenditure',
+ cascade='all, delete')
+})
+
+orm.mapper(Split, splits, properties={
+ 'user': orm.relation(User)
+})
+
+orm.mapper(Tag, tags, properties={
+ 'expenditures': orm.relation(Expenditure, secondary=tag_to_expense_map)})
+
+orm.mapper(Subitem, subitems, properties={
+ 'user': orm.relation(User)
+})
+
+orm.mapper(Transfer, transfers,
+ order_by=[transfers.c.date.desc(), transfers.c.entered_time.desc()],
+ 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))
+})