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# connectors/mxodbc.py
# Copyright (C) 2005-2011 the SQLAlchemy authors and contributors <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""
Provide an SQLALchemy connector for the eGenix mxODBC commercial
Python adapter for ODBC. This is not a free product, but eGenix
provides SQLAlchemy with a license for use in continuous integration
testing.
This has been tested for use with mxODBC 3.1.2 on SQL Server 2005
and 2008, using the SQL Server Native driver. However, it is
possible for this to be used on other database platforms.
For more info on mxODBC, see http://www.egenix.com/
"""
import sys
import re
import warnings
from sqlalchemy.connectors import Connector
class MxODBCConnector(Connector):
driver='mxodbc'
supports_sane_multi_rowcount = False
supports_unicode_statements = False
supports_unicode_binds = False
supports_native_decimal = True
@classmethod
def dbapi(cls):
# this classmethod will normally be replaced by an instance
# attribute of the same name, so this is normally only called once.
cls._load_mx_exceptions()
platform = sys.platform
if platform == 'win32':
from mx.ODBC import Windows as module
# this can be the string "linux2", and possibly others
elif 'linux' in platform:
from mx.ODBC import unixODBC as module
elif platform == 'darwin':
from mx.ODBC import iODBC as module
else:
raise ImportError, "Unrecognized platform for mxODBC import"
return module
@classmethod
def _load_mx_exceptions(cls):
""" Import mxODBC exception classes into the module namespace,
as if they had been imported normally. This is done here
to avoid requiring all SQLAlchemy users to install mxODBC.
"""
global InterfaceError, ProgrammingError
from mx.ODBC import InterfaceError
from mx.ODBC import ProgrammingError
def on_connect(self):
def connect(conn):
conn.stringformat = self.dbapi.MIXED_STRINGFORMAT
conn.datetimeformat = self.dbapi.PYDATETIME_DATETIMEFORMAT
conn.decimalformat = self.dbapi.DECIMAL_DECIMALFORMAT
conn.errorhandler = self._error_handler()
return connect
def _error_handler(self):
""" Return a handler that adjusts mxODBC's raised Warnings to
emit Python standard warnings.
"""
from mx.ODBC.Error import Warning as MxOdbcWarning
def error_handler(connection, cursor, errorclass, errorvalue):
if issubclass(errorclass, MxOdbcWarning):
errorclass.__bases__ = (Warning,)
warnings.warn(message=str(errorvalue),
category=errorclass,
stacklevel=2)
else:
raise errorclass, errorvalue
return error_handler
def create_connect_args(self, url):
""" Return a tuple of *args,**kwargs for creating a connection.
The mxODBC 3.x connection constructor looks like this:
connect(dsn, user='', password='',
clear_auto_commit=1, errorhandler=None)
This method translates the values in the provided uri
into args and kwargs needed to instantiate an mxODBC Connection.
The arg 'errorhandler' is not used by SQLAlchemy and will
not be populated.
"""
opts = url.translate_connect_args(username='user')
opts.update(url.query)
args = opts.pop('host')
opts.pop('port', None)
opts.pop('database', None)
return (args,), opts
def is_disconnect(self, e, connection, cursor):
# TODO: eGenix recommends checking connection.closed here
# Does that detect dropped connections ?
if isinstance(e, self.dbapi.ProgrammingError):
return "connection already closed" in str(e)
elif isinstance(e, self.dbapi.Error):
return '[08S01]' in str(e)
else:
return False
def _get_server_version_info(self, connection):
# eGenix suggests using conn.dbms_version instead
# of what we're doing here
dbapi_con = connection.connection
version = []
r = re.compile('[.\-]')
# 18 == pyodbc.SQL_DBMS_VER
for n in r.split(dbapi_con.getinfo(18)[1]):
try:
version.append(int(n))
except ValueError:
version.append(n)
return tuple(version)
def do_execute(self, cursor, statement, parameters, context=None):
if context:
native_odbc_execute = context.execution_options.\
get('native_odbc_execute', 'auto')
if native_odbc_execute is True:
# user specified native_odbc_execute=True
cursor.execute(statement, parameters)
elif native_odbc_execute is False:
# user specified native_odbc_execute=False
cursor.executedirect(statement, parameters)
elif context.is_crud:
# statement is UPDATE, DELETE, INSERT
cursor.execute(statement, parameters)
else:
# all other statements
cursor.executedirect(statement, parameters)
else:
cursor.executedirect(statement, parameters)
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