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                  sa.Column('password', sa.types.Unicode(64)),
  33                  )
  34
  35 expenditures = sa.Table('expenditures', meta.metadata,
  36                         sa.Column('id', sa.types.Integer, primary_key=True),
  37                         sa.Column('spender_id', sa.types.Integer,
  38                                   sa.ForeignKey('users.id'), nullable=False),
  39                         sa.Column('amount', types.DBCurrency, nullable=False),
  40                         sa.Column('description', sa.types.Text),
  41                         sa.Column('date', sa.types.Date, default=datetime.now),
  42                         sa.Column('entered_time', sa.types.DateTime,
  43                                   default=datetime.utcnow)
  44                         )
  45
  46 splits = sa.Table('splits', meta.metadata,
  47                   sa.Column('id', sa.types.Integer, primary_key=True),
  48                   sa.Column('expenditure_id', sa.types.Integer,
  49                             sa.ForeignKey('expenditures.id'), nullable=False),
  50                   sa.Column('user_id', sa.types.Integer,
  51                             sa.ForeignKey('users.id'), nullable=False),
  52                   sa.Column('share', types.DBCurrency, nullable=False)
  53                   )
  54
  55 subitems = sa.Table('subitems', meta.metadata,
  56                     sa.Column('id', sa.types.Integer, primary_key=True),
  57                     sa.Column('expenditure_id', sa.types.Integer,
  58                               sa.ForeignKey('expenditures.id'), nullable=False),
  59                     sa.Column('user_id', sa.types.Integer,
  60                               sa.ForeignKey('users.id'), nullable=False),
  61                     sa.Column('amount', types.DBCurrency, nullable=False)
  62                     )
  63
  64 transfers = sa.Table('transfers', meta.metadata,
  65                      sa.Column('id', sa.types.Integer, primary_key=True),
  66                      sa.Column('debtor_id', sa.types.Integer,
  67                                sa.ForeignKey('users.id'), nullable=False),
  68                      sa.Column('creditor_id', sa.types.Integer,
  69                                sa.ForeignKey('users.id'), nullable=False),
  70                      sa.Column('amount', types.DBCurrency, nullable=False),
  71                      sa.Column('description', sa.Text, default=None),
  72                      sa.Column('date', sa.types.Date, default=datetime.now),
  73                      sa.Column('entered_time', sa.types.DateTime,
  74                                default=datetime.utcnow)
  75                      )
  76
  77 ### DB/Class Mapping ###
  78
  79 orm.mapper(User, users,
  80            properties={
  81         'expenditures': orm.relation(Expenditure,
  82                                      backref='spender')
  83 })
  84
  85 orm.mapper(Expenditure, expenditures,
  86            order_by=[expenditures.c.date.desc(), expenditures.c.entered_time.desc()],
  87            properties={
  88         'splits': orm.relation(Split, backref='expenditure',
  89                                cascade='all, delete'),
  90         'subitems': orm.relation(Subitem, backref='expenditure',
  91                                  cascade='all, delete')
  92 })
  93
  94 orm.mapper(Split, splits, properties={
  95         'user': orm.relation(User)
  96 })
  97
  98 orm.mapper(Subitem, subitems, properties={
  99         'user': orm.relation(User)
 100 })
 101
 102 orm.mapper(Transfer, transfers,
 103            order_by=[transfers.c.date.desc(), transfers.c.entered_time.desc()],
 104            properties={
 105         'debtor': orm.relation(User,
 106                                primaryjoin=(transfers.c.debtor_id==\
 107                                                 users.c.id)),
 108         'creditor': orm.relation(User,
 109                                  primaryjoin=(transfers.c.creditor_id==\
 110                                                   users.c.id))
 111 })
 112
 113 __all__ = ['users', 'expenditures', 'splits', 'subitems', 'transfers',
 114            'User', 'Expenditure', 'Split', 'Subitem', 'Transfer',
 115            'meta']