100 lines
3.0 KiB
Python
100 lines
3.0 KiB
Python
# mssql/pymssql.py
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# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""
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.. dialect:: mssql+pymssql
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:name: pymssql
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:dbapi: pymssql
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:connectstring: mssql+pymssql://<username>:<password>@<freetds_name>?charset=utf8
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:url: http://pymssql.sourceforge.net/
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Limitations
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-----------
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pymssql inherits a lot of limitations from FreeTDS, including:
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* no support for multibyte schema identifiers
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* poor support for large decimals
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* poor support for binary fields
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* poor support for VARCHAR/CHAR fields over 255 characters
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Please consult the pymssql documentation for further information.
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"""
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from .base import MSDialect
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from ... import types as sqltypes, util, processors
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import re
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class _MSNumeric_pymssql(sqltypes.Numeric):
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def result_processor(self, dialect, type_):
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if not self.asdecimal:
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return processors.to_float
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else:
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return sqltypes.Numeric.result_processor(self, dialect, type_)
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class MSDialect_pymssql(MSDialect):
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supports_sane_rowcount = False
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driver = 'pymssql'
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colspecs = util.update_copy(
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MSDialect.colspecs,
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{
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sqltypes.Numeric: _MSNumeric_pymssql,
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sqltypes.Float: sqltypes.Float,
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}
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)
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@classmethod
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def dbapi(cls):
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module = __import__('pymssql')
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# pymmsql doesn't have a Binary method. we use string
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# TODO: monkeypatching here is less than ideal
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module.Binary = lambda x: x if hasattr(x, 'decode') else str(x)
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client_ver = tuple(int(x) for x in module.__version__.split("."))
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if client_ver < (1, ):
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util.warn("The pymssql dialect expects at least "
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"the 1.0 series of the pymssql DBAPI.")
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return module
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def __init__(self, **params):
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super(MSDialect_pymssql, self).__init__(**params)
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self.use_scope_identity = True
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def _get_server_version_info(self, connection):
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vers = connection.scalar("select @@version")
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m = re.match(
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r"Microsoft SQL Server.*? - (\d+).(\d+).(\d+).(\d+)", vers)
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if m:
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return tuple(int(x) for x in m.group(1, 2, 3, 4))
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else:
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return None
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def create_connect_args(self, url):
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opts = url.translate_connect_args(username='user')
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opts.update(url.query)
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port = opts.pop('port', None)
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if port and 'host' in opts:
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opts['host'] = "%s:%s" % (opts['host'], port)
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return [[], opts]
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def is_disconnect(self, e, connection, cursor):
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for msg in (
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"Adaptive Server connection timed out",
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"message 20003", # connection timeout
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"Error 10054",
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"Not connected to any MS SQL server",
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"Connection is closed"
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):
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if msg in str(e):
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return True
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else:
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return False
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dialect = MSDialect_pymssql
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