veekun_pokedex/pokedex/db/__init__.py

46 lines
1.6 KiB
Python

from sqlalchemy import MetaData, Table, engine_from_config, orm
from ..defaults import get_default_db_uri
from .tables import metadata
def connect(uri=None, session_args={}, engine_args={}, engine_prefix=''):
"""Connects to the requested URI. Returns a session object.
With the URI omitted, attempts to connect to a default SQLite database
contained within the package directory.
Calling this function also binds the metadata object to the created engine.
"""
# If we didn't get a uri, fall back to the default
if uri is None:
uri = engine_args[engine_prefix + 'url']
if uri is None:
uri = get_default_db_uri()
### Do some fixery for MySQL
if uri[0:5] == 'mysql':
# MySQL uses latin1 for connections by default even if the server is
# otherwise oozing with utf8; charset fixes this
if 'charset' not in uri:
uri += '?charset=utf8'
# Tables should be InnoDB, in the event that we're creating them, and
# use UTF-8 goddammit!
for table in metadata.tables.values():
table.kwargs['mysql_engine'] = 'InnoDB'
table.kwargs['mysql_charset'] = 'utf8'
### Connect
engine_args[engine_prefix + 'url'] = uri
engine = engine_from_config(engine_args, prefix=engine_prefix)
conn = engine.connect()
metadata.bind = engine
all_session_args = dict(autoflush=True, autocommit=False, bind=engine)
all_session_args.update(session_args)
sm = orm.sessionmaker(**all_session_args)
session = orm.scoped_session(sm)
return session