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Python

# mssql/pymssql.py
# Copyright (C) 2005-2022 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: https://www.opensource.org/licenses/mit-license.php
"""
.. dialect:: mssql+pymssql
:name: pymssql
:dbapi: pymssql
:connectstring: mssql+pymssql://<username>:<password>@<freetds_name>/?charset=utf8
pymssql is a Python module that provides a Python DBAPI interface around
`FreeTDS <https://www.freetds.org/>`_.
.. note::
pymssql is currently not included in SQLAlchemy's continuous integration
(CI) testing.
""" # noqa
import re
from .base import MSDialect
from .base import MSIdentifierPreparer
from ... import processors
from ... import types as sqltypes
from ... import util
class _MSNumeric_pymssql(sqltypes.Numeric):
def result_processor(self, dialect, type_):
if not self.asdecimal:
return processors.to_float
else:
return sqltypes.Numeric.result_processor(self, dialect, type_)
class MSIdentifierPreparer_pymssql(MSIdentifierPreparer):
def __init__(self, dialect):
super(MSIdentifierPreparer_pymssql, self).__init__(dialect)
# pymssql has the very unusual behavior that it uses pyformat
# yet does not require that percent signs be doubled
self._double_percents = False
class MSDialect_pymssql(MSDialect):
supports_statement_cache = True
supports_native_decimal = True
driver = "pymssql"
preparer = MSIdentifierPreparer_pymssql
colspecs = util.update_copy(
MSDialect.colspecs,
{sqltypes.Numeric: _MSNumeric_pymssql, sqltypes.Float: sqltypes.Float},
)
@classmethod
def dbapi(cls):
module = __import__("pymssql")
# pymmsql < 2.1.1 doesn't have a Binary method. we use string
client_ver = tuple(int(x) for x in module.__version__.split("."))
if client_ver < (2, 1, 1):
# TODO: monkeypatching here is less than ideal
module.Binary = lambda x: x if hasattr(x, "decode") else str(x)
if client_ver < (1,):
util.warn(
"The pymssql dialect expects at least "
"the 1.0 series of the pymssql DBAPI."
)
return module
def _get_server_version_info(self, connection):
vers = connection.exec_driver_sql("select @@version").scalar()
m = re.match(r"Microsoft .*? - (\d+)\.(\d+)\.(\d+)\.(\d+)", vers)
if m:
return tuple(int(x) for x in m.group(1, 2, 3, 4))
else:
return None
def create_connect_args(self, url):
opts = url.translate_connect_args(username="user")
opts.update(url.query)
port = opts.pop("port", None)
if port and "host" in opts:
opts["host"] = "%s:%s" % (opts["host"], port)
return [[], opts]
def is_disconnect(self, e, connection, cursor):
for msg in (
"Adaptive Server connection timed out",
"Net-Lib error during Connection reset by peer",
"message 20003", # connection timeout
"Error 10054",
"Not connected to any MS SQL server",
"Connection is closed",
"message 20006", # Write to the server failed
"message 20017", # Unexpected EOF from the server
"message 20047", # DBPROCESS is dead or not enabled
):
if msg in str(e):
return True
else:
return False
def set_isolation_level(self, connection, level):
if level == "AUTOCOMMIT":
connection.autocommit(True)
else:
connection.autocommit(False)
super(MSDialect_pymssql, self).set_isolation_level(
connection, level
)
dialect = MSDialect_pymssql