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
   6
   7 def connect(uri=None, session_args={}, engine_args={}, engine_prefix=''):
   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 = engine_args.get(engine_prefix + 'url', None)
  19     if uri is None:
  20         uri = get_default_db_uri()
  21
  22     ### Do some fixery for MySQL
  23     if uri[0:5] == 'mysql':
  24         # MySQL uses latin1 for connections by default even if the server is
  25         # otherwise oozing with utf8; charset fixes this
  26         if 'charset' not in uri:
  27             uri += '?charset=utf8'
  28
  29         # Tables should be InnoDB, in the event that we're creating them, and
  30         # use UTF-8 goddammit!
  31         for table in metadata.tables.values():
  32             table.kwargs['mysql_engine'] = 'InnoDB'
  33             table.kwargs['mysql_charset'] = 'utf8'
  34
  35     ### Connect
  36     engine_args[engine_prefix + 'url'] = uri
  37     engine = engine_from_config(engine_args, prefix=engine_prefix)
  38     conn = engine.connect()
  39     metadata.bind = engine
  40
  41     all_session_args = dict(autoflush=True, autocommit=False, bind=engine)
  42     all_session_args.update(session_args)
  43     sm = orm.sessionmaker(**all_session_args)
  44     session = orm.scoped_session(sm)
  45
  46     return session