bluechips/model/__init__.py

   1 """The application's model objects"""
   2 import sqlalchemy as sa
   3 from sqlalchemy import orm
   4
   5 from bluechips.model import meta
   6 from bluechips.model import types
   7
   8 def init_model(engine):
   9     """Call me before using any of the tables or classes in the model"""
  10     ## Reflected tables must be defined and mapped here
  11     #global reflected_table
  12     #reflected_table = sa.Table("Reflected", meta.metadata, autoload=True,
  13     #                           autoload_with=engine)
  14     #orm.mapper(Reflected, reflected_table)
  15
  16     sm = orm.sessionmaker(autoflush=True, transactional=True, bind=engine)
  17
  18     meta.engine = engine
  19     meta.Session = orm.scoped_session(sm)
  20
  21 ### Database Schemas ###
  22
  23 users = sa.Table('users', meta.metadata,
  24                  sa.Column('id', sa.types.Integer, primary_key=True),
  25                  sa.Column('username', sa.types.Unicode(32), nullable=False),
  26                  sa.Column('name', sa.types.Unicode(64)),
  27                  sa.Column('resident', sa.types.Boolean, default=True)
  28                  )
  29
  30 expenditures = sa.Table('expenditures', meta.metadata,
  31                         sa.Column('id', sa.types.Integer, primary_key=True),
  32                         sa.Column('spender_id', sa.types.Integer,
  33                                   sa.ForeignKey('users.id'), nullable=False),
  34                         sa.Column('amount', types.Currency, nullable=False),
  35                         sa.Column('date', sa.types.Date, default=sa.func.now),
  36                         sa.Column('entered_time', sa.types.DateTime,
  37                                   default=sa.func.now)
  38                         )
  39
  40 splits = sa.Table('splits', meta.metadata,
  41                   sa.Column('id', sa.types.Integer, primary_key=True),
  42                   sa.Column('expenditure_id', sa.types.Integer,
  43                             sa.ForeignKey('expenditures.id'), nullable=False),
  44                   sa.Column('user_id', sa.types.Integer,
  45                             sa.ForeignKey('users.id'), nullable=False),
  46                   sa.Column('share', sa.types.Integer, nullable=False)
  47                   )
  48
  49 subitems = sa.Table('subitems', meta.metadata,
  50                     sa.Column('id', sa.types.Integer, primary_key=True),
  51                     sa.Column('expenditure_id', sa.types.Integer,
  52                               sa.ForeignKey('expenditures.id'), nullable=False),
  53                     sa.Column('user_id', sa.types.Integer,
  54                               sa.ForeignKey('users.id'), nullable=False),
  55                     sa.Column('amount', types.Currency, nullable=False)
  56                     )
  57
  58 transfers = sa.Table('transfers', meta.metadata,
  59                      sa.Column('id', sa.types.Integer, primary_key=True),
  60                      sa.Column('debtor_id', sa.types.Integer,
  61                                sa.ForeignKey('users.id'), nullable=False),
  62                      sa.Column('creditor_id', sa.types.Integer,
  63                                sa.ForeignKey('users.id'), nullable=False),
  64                      sa.Column('amount', types.Currency, nullable=False),
  65                      sa.Column('date', sa.types.Date, default=sa.func.now),
  66                      sa.Column('entered_time', sa.types.DateTime,
  67                                default=sa.func.now),
  68                      sa.Column('desc', sa.Text, default=None)
  69                      )
  70
  71 ### ORM Classes ###
  72
  73 class User(object):
  74     def __repr__(self):
  75         return '<User: %w>' % (self.username)
  76
  77 class Expenditure(object):
  78     def __repr__(self):
  79         return '<Expenditure: spender: %s spent: %s>' % (self.spender,
  80                                                self.amount)
  81
  82 class Split(object):
  83     def __repr__(self):
  84         return '<Split: expense: %s user: %s share: %s%%>' % (self.expenditure,
  85                                                               self.user,
  86                                                               self.share)
  87
  88 class Subitem(object):
  89     def __repr__(self):
  90         return '<Subitem: expense: %s user: %s cost: %s>' % (self.expense,
  91                                                              self.user,
  92                                                              self.amount)
  93
  94 class Transfer(object):
  95     def __repr__(self):
  96         return '<Transfer: from %s to %s for %s>' % (self.debtor,
  97                                                      self.creditor,
  98                                                      self.amount)
  99
 100 ### DB/Class Mapping ###
 101
 102 orm.mapper(User, users)
 103
 104 orm.mapper(Expenditure, expenditures, properties={
 105         'spender': orm.relation(User, backref='expenditures')
 106 })
 107
 108 orm.mapper(Split, splits, properties={
 109         'expenditure': orm.relation(Expenditure, backref='splits'),
 110         'user': orm.relation(User)
 111 })
 112
 113 orm.mapper(Subitem, subitems, properties={
 114         'expenditure': orm.relation(Expenditure, backref='subitems'),
 115         'user': orm.relation(User)
 116 })
 117
 118 orm.mapper(Transfer, transfers, properties={
 119         'debtor': orm.relation(User),
 120         'creditor': orm.relation(User)
 121 })
 122
 123 __all__ = [users, expenditures, splits, subitems, transfers,
 124            User, Expenditure, Split, Subitem, Transfer,
 125            meta]