from sqlalchemy.connectors import Connector
from sqlalchemy.util import asbool
import sys
import re
import urllib
import decimal
class PyODBCConnector(Connector):
driver='pyodbc'
supports_sane_multi_rowcount = False
# PyODBC unicode is broken on UCS-4 builds
supports_unicode = sys.maxunicode == 65535
supports_unicode_statements = supports_unicode
supports_native_decimal = True
default_paramstyle = 'named'
# for non-DSN connections, this should
# hold the desired driver name
pyodbc_driver_name = None
# will be set to True after initialize()
# if the freetds.so is detected
freetds = False
@classmethod
def dbapi(cls):
return __import__('pyodbc')
def create_connect_args(self, url):
opts = url.translate_connect_args(username='user')
opts.update(url.query)
keys = opts
query = url.query
connect_args = {}
for param in ('ansi', 'unicode_results', 'autocommit'):
if param in keys:
connect_args[param] = asbool(keys.pop(param))
if 'odbc_connect' in keys:
connectors = [urllib.unquote_plus(keys.pop('odbc_connect'))]
else:
dsn_connection = 'dsn' in keys or ('host' in keys and 'database' not in keys)
if dsn_connection:
connectors= ['dsn=%s' % (keys.pop('host', '') or keys.pop('dsn', ''))]
else:
port = ''
if 'port' in keys and not 'port' in query:
port = ',%d' % int(keys.pop('port'))
connectors = ["DRIVER={%s}" % keys.pop('driver', self.pyodbc_driver_name),
'Server=%s%s' % (keys.pop('host', ''), port),
'Database=%s' % keys.pop('database', '') ]
user = keys.pop("user", None)
if user:
connectors.append("UID=%s" % user)
connectors.append("PWD=%s" % keys.pop('password', ''))
else:
connectors.append("Trusted_Connection=Yes")
# if set to 'Yes', the ODBC layer will try to automagically convert
# textual data from your database encoding to your client encoding
# This should obviously be set to 'No' if you query a cp1253 encoded
# database from a latin1 client...
if 'odbc_autotranslate' in keys:
connectors.append("AutoTranslate=%s" % keys.pop("odbc_autotranslate"))
connectors.extend(['%s=%s' % (k,v) for k,v in keys.iteritems()])
return [[";".join (connectors)], connect_args]
def is_disconnect(self, e):
if isinstance(e, self.dbapi.ProgrammingError):
return "The cursor's connection has been closed." in str(e) or \
'Attempt to use a closed connection.' in str(e)
elif isinstance(e, self.dbapi.Error):
return '[08S01]' in str(e)
else:
return False
def initialize(self, connection):
# determine FreeTDS first. can't issue SQL easily
# without getting unicode_statements/binds set up.
pyodbc = self.dbapi
dbapi_con = connection.connection
self.freetds = bool(re.match(r".*libtdsodbc.*\.so", dbapi_con.getinfo(pyodbc.SQL_DRIVER_NAME)))
# the "Py2K only" part here is theoretical.
# have not tried pyodbc + python3.1 yet.
# Py2K
self.supports_unicode_statements = not self.freetds
self.supports_unicode_binds = not self.freetds
# end Py2K
# run other initialization which asks for user name, etc.
super(PyODBCConnector, self).initialize(connection)
def _get_server_version_info(self, connection):
dbapi_con = connection.connection
version = []
r = re.compile('[.\-]')
for n in r.split(dbapi_con.getinfo(self.dbapi.SQL_DBMS_VER)):
try:
version.append(int(n))
except ValueError:
version.append(n)
return tuple(version)
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