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.user import User
   6 from bluechips.model.expenditure import Expenditure
   7 from bluechips.model.split import Split
   8 from bluechips.model.subitem import Subitem
   9 from bluechips.model.transfer import Transfer
  10
  11 from bluechips.model import meta
  12 from bluechips.model import types
  13
  14 from datetime import datetime
  15
  16 def init_model(engine):
  17     """Call me before using any of the tables or classes in the model"""
  18
  19     sm = orm.sessionmaker(autoflush=True, bind=engine)
  20
  21     meta.engine = engine
  22     meta.Session = orm.scoped_session(sm)
  23
  24 ### Database Schemas ###
  25
  26 users = sa.Table('users', meta.metadata,
  27                  sa.Column('id', sa.types.Integer, primary_key=True),
  28                  sa.Column('username', sa.types.Unicode(32), nullable=False),
  29                  sa.Column('name', sa.types.Unicode(64)),
  30                  sa.Column('resident', sa.types.Boolean, default=True),
  31                  sa.Column('email', sa.types.Unicode(64))
  32                  )
  33
  34 expenditures = sa.Table('expenditures', meta.metadata,
  35                         sa.Column('id', sa.types.Integer, primary_key=True),
  36                         sa.Column('spender_id', sa.types.Integer,
  37                                   sa.ForeignKey('users.id'), nullable=False),
  38                         sa.Column('amount', types.DBCurrency, nullable=False),
  39                         sa.Column('description', sa.types.Text),
  40                         sa.Column('date', sa.types.Date, default=datetime.now),
  41                         sa.Column('entered_time', sa.types.DateTime,
  42                                   default=datetime.utcnow)
  43                         )
  44
  45 splits = sa.Table('splits', meta.metadata,
  46                   sa.Column('id', sa.types.Integer, primary_key=True),
  47                   sa.Column('expenditure_id', sa.types.Integer,
  48                             sa.ForeignKey('expenditures.id'), nullable=False),
  49                   sa.Column('user_id', sa.types.Integer,
  50                             sa.ForeignKey('users.id'), nullable=False),
  51                   sa.Column('share', types.DBCurrency, nullable=False)
  52                   )
  53
  54 subitems = sa.Table('subitems', meta.metadata,
  55                     sa.Column('id', sa.types.Integer, primary_key=True),
  56                     sa.Column('expenditure_id', sa.types.Integer,
  57                               sa.ForeignKey('expenditures.id'), nullable=False),
  58                     sa.Column('user_id', sa.types.Integer,
  59                               sa.ForeignKey('users.id'), nullable=False),
  60                     sa.Column('amount', types.DBCurrency, nullable=False)
  61                     )
  62
  63 transfers = sa.Table('transfers', meta.metadata,
  64                      sa.Column('id', sa.types.Integer, primary_key=True),
  65                      sa.Column('debtor_id', sa.types.Integer,
  66                                sa.ForeignKey('users.id'), nullable=False),
  67                      sa.Column('creditor_id', sa.types.Integer,
  68                                sa.ForeignKey('users.id'), nullable=False),
  69                      sa.Column('amount', types.DBCurrency, nullable=False),
  70                      sa.Column('description', sa.Text, default=None),
  71                      sa.Column('date', sa.types.Date, default=datetime.now),
  72                      sa.Column('entered_time', sa.types.DateTime,
  73                                default=datetime.utcnow)
  74                      )
  75
  76 ### DB/Class Mapping ###
  77
  78 orm.mapper(User, users,
  79            properties={
  80         'expenditures': orm.relation(Expenditure,
  81                                      backref='spender')
  82 })
  83
  84 orm.mapper(Expenditure, expenditures,
  85            order_by=[expenditures.c.date.desc(), expenditures.c.entered_time.desc()],
  86            properties={
  87         'splits': orm.relation(Split, backref='expenditure',
  88                                cascade='all, delete'),
  89         'subitems': orm.relation(Subitem, backref='expenditure',
  90                                  cascade='all, delete')
  91 })
  92
  93 orm.mapper(Split, splits, properties={
  94         'user': orm.relation(User)
  95 })
  96
  97 orm.mapper(Subitem, subitems, properties={
  98         'user': orm.relation(User)
  99 })
 100
 101 orm.mapper(Transfer, transfers,
 102            order_by=[transfers.c.date.desc(), transfers.c.entered_time.desc()],
 103            properties={
 104         'debtor': orm.relation(User,
 105                                primaryjoin=(transfers.c.debtor_id==\
 106                                                 users.c.id)),
 107         'creditor': orm.relation(User,
 108                                  primaryjoin=(transfers.c.creditor_id==\
 109                                                   users.c.id))
 110 })
 111
 112 __all__ = ['users', 'expenditures', 'splits', 'subitems', 'transfers',
 113            'User', 'Expenditure', 'Split', 'Subitem', 'Transfer',
 114            'meta']