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 from bluechips.model.tag import Tag
  11
  12 from bluechips.model import meta
  13 from bluechips.model import types
  14
  15 from datetime import datetime
  16
  17 def init_model(engine):
  18     """Call me before using any of the tables or classes in the model"""
  19
  20     sm = orm.sessionmaker(autoflush=True, bind=engine)
  21
  22     meta.engine = engine
  23     meta.Session = orm.scoped_session(sm)
  24
  25 ### Database Schemas ###
  26
  27 users = sa.Table('users', meta.metadata,
  28                  sa.Column('id', sa.types.Integer, primary_key=True),
  29                  sa.Column('username', sa.types.Unicode(32), nullable=False),
  30                  sa.Column('name', sa.types.Unicode(64)),
  31                  sa.Column('resident', sa.types.Boolean, default=True),
  32                  sa.Column('email', sa.types.Unicode(64)),
  33                  sa.Column('password', sa.types.Unicode(64)),
  34                  )
  35
  36 expenditures = sa.Table('expenditures', meta.metadata,
  37                         sa.Column('id', sa.types.Integer, primary_key=True),
  38                         sa.Column('spender_id', sa.types.Integer,
  39                                   sa.ForeignKey('users.id'), nullable=False),
  40                         sa.Column('amount', types.DBCurrency, nullable=False),
  41                         sa.Column('description', sa.types.Text),
  42                         sa.Column('date', sa.types.Date, default=datetime.now),
  43                         sa.Column('entered_time', sa.types.DateTime,
  44                                   default=datetime.utcnow)
  45                         )
  46
  47 splits = sa.Table('splits', meta.metadata,
  48                   sa.Column('id', sa.types.Integer, primary_key=True),
  49                   sa.Column('expenditure_id', sa.types.Integer,
  50                             sa.ForeignKey('expenditures.id'), nullable=False),
  51                   sa.Column('user_id', sa.types.Integer,
  52                             sa.ForeignKey('users.id'), nullable=False),
  53                   sa.Column('share_text', sa.Text, nullable=False),
  54                   sa.Column('share', types.DBCurrency, nullable=False)
  55                   )
  56
  57 tags = sa.Table('tags', meta.metadata,
  58                 sa.Column('id', sa.types.Integer, primary_key=True),
  59                 sa.Column('name', sa.Text))
  60
  61 tag_to_expense_map = sa.Table('tag_to_expense_map', meta.metadata,
  62                               sa.Column('tag_id', sa.types.Integer,
  63                                         sa.ForeignKey('tags.id'),
  64                                         primary_key=True),
  65                               sa.Column('expenditure_id', sa.types.Integer,
  66                                         sa.ForeignKey('expenditures.id'),
  67                                         primary_key=True))
  68
  69 subitems = sa.Table('subitems', meta.metadata,
  70                     sa.Column('id', sa.types.Integer, primary_key=True),
  71                     sa.Column('expenditure_id', sa.types.Integer,
  72                               sa.ForeignKey('expenditures.id'), nullable=False),
  73                     sa.Column('user_id', sa.types.Integer,
  74                               sa.ForeignKey('users.id'), nullable=False),
  75                     sa.Column('amount', types.DBCurrency, nullable=False)
  76                     )
  77
  78 transfers = sa.Table('transfers', meta.metadata,
  79                      sa.Column('id', sa.types.Integer, primary_key=True),
  80                      sa.Column('debtor_id', sa.types.Integer,
  81                                sa.ForeignKey('users.id'), nullable=False),
  82                      sa.Column('creditor_id', sa.types.Integer,
  83                                sa.ForeignKey('users.id'), nullable=False),
  84                      sa.Column('amount', types.DBCurrency, nullable=False),
  85                      sa.Column('description', sa.Text, default=None),
  86                      sa.Column('date', sa.types.Date, default=datetime.now),
  87                      sa.Column('entered_time', sa.types.DateTime,
  88                                default=datetime.utcnow)
  89                      )
  90
  91 ### DB/Class Mapping ###
  92
  93 orm.mapper(User, users,
  94            properties={
  95         'expenditures': orm.relation(Expenditure,
  96                                      backref='spender')
  97 })
  98
  99 orm.mapper(Expenditure, expenditures,
 100            order_by=[expenditures.c.date.desc(), expenditures.c.entered_time.desc()],
 101            properties={
 102         'splits': orm.relation(Split, backref='expenditure',
 103                                cascade='all, delete'),
 104         '_tags': orm.relation(Tag, secondary=tag_to_expense_map,
 105                              collection_class=set, cascade='all, delete'),
 106         'subitems': orm.relation(Subitem, backref='expenditure',
 107                                  cascade='all, delete')
 108 })
 109
 110 orm.mapper(Split, splits, properties={
 111         'user': orm.relation(User)
 112 })
 113
 114 orm.mapper(Tag, tags, properties={
 115         'expenditures': orm.relation(Expenditure, secondary=tag_to_expense_map)})
 116
 117 orm.mapper(Subitem, subitems, properties={
 118         'user': orm.relation(User)
 119 })
 120
 121 orm.mapper(Transfer, transfers,
 122            order_by=[transfers.c.date.desc(), transfers.c.entered_time.desc()],
 123            properties={
 124         'debtor': orm.relation(User,
 125                                primaryjoin=(transfers.c.debtor_id==\
 126                                                 users.c.id)),
 127         'creditor': orm.relation(User,
 128                                  primaryjoin=(transfers.c.creditor_id==\
 129                                                   users.c.id))
 130 })
 131
 132 __all__ = ['users', 'expenditures', 'splits', 'tags', 'subitems', 'transfers',
 133            'User', 'Expenditure', 'Split', 'Tag', 'Subitem', 'Transfer',
 134            'meta']