pokedex/db/__init__.py

   1 from sqlalchemy import MetaData, Table, create_engine, orm
   2
   3 from ..defaults import get_default_db_uri
   4 from .tables import metadata
   5
   6
   7 def connect(uri=None, session_args={}, engine_args={}):
   8     """Connects to the requested URI.  Returns a session object.
   9
  10     With the URI omitted, attempts to connect to a default SQLite database
  11     contained within the package directory.
  12
  13     Calling this function also binds the metadata object to the created engine.
  14     """
  15
  16     # If we didn't get a uri, fall back to the default
  17     if uri is None:
  18         uri = get_default_db_uri()
  19
  20     ### Do some fixery for MySQL
  21     if uri[0:5] == 'mysql':
  22         # MySQL uses latin1 for connections by default even if the server is
  23         # otherwise oozing with utf8; charset fixes this
  24         if 'charset' not in uri:
  25             uri += '?charset=utf8'
  26
  27         # Tables should be InnoDB, in the event that we're creating them, and
  28         # use UTF-8 goddammit!
  29         for table in metadata.tables.values():
  30             table.kwargs['mysql_engine'] = 'InnoDB'
  31             table.kwargs['mysql_charset'] = 'utf8'
  32
  33     ### Connect
  34     engine = create_engine(uri, **engine_args)
  35     conn = engine.connect()
  36     metadata.bind = engine
  37
  38     all_session_args = dict(autoflush=True, autocommit=False, bind=engine)
  39     all_session_args.update(session_args)
  40     sm = orm.sessionmaker(**all_session_args)
  41     session = orm.scoped_session(sm)
  42
  43     return session