pokedex/db/__init__.py

   1 from sqlalchemy import MetaData, Table, engine_from_config, orm
   2
   3 from ..defaults import get_default_db_uri
   4 from .tables import metadata
   5 from .multilang import MultilangSession
   6
   7
   8 def connect(uri=None, session_args={}, engine_args={}, engine_prefix=''):
   9     """Connects to the requested URI.  Returns a session object.
  10
  11     With the URI omitted, attempts to connect to a default SQLite database
  12     contained within the package directory.
  13
  14     Calling this function also binds the metadata object to the created engine.
  15     """
  16
  17     # If we didn't get a uri, fall back to the default
  18     if uri is None:
  19         uri = engine_args.get(engine_prefix + 'url', None)
  20     if uri is None:
  21         uri = get_default_db_uri()
  22
  23     ### Do some fixery for MySQL
  24     if uri[0:5] == 'mysql':
  25         # MySQL uses latin1 for connections by default even if the server is
  26         # otherwise oozing with utf8; charset fixes this
  27         if 'charset' not in uri:
  28             uri += '?charset=utf8'
  29
  30         # Tables should be InnoDB, in the event that we're creating them, and
  31         # use UTF-8 goddammit!
  32         for table in metadata.tables.values():
  33             table.kwargs['mysql_engine'] = 'InnoDB'
  34             table.kwargs['mysql_charset'] = 'utf8'
  35
  36     ### Connect
  37     engine_args[engine_prefix + 'url'] = uri
  38     engine = engine_from_config(engine_args, prefix=engine_prefix)
  39     conn = engine.connect()
  40     metadata.bind = engine
  41
  42     all_session_args = dict(autoflush=True, autocommit=False, bind=engine)
  43     all_session_args.update(session_args)
  44     sm = orm.sessionmaker(class_=MultilangSession, **all_session_args)
  45     session = orm.scoped_session(sm)
  46
  47     return session