From 1dac2263372df2b85db5d029a45721fa158a5c9d Mon Sep 17 00:00:00 2001 From: xiubuzhe Date: Sun, 8 Oct 2023 20:59:00 +0800 Subject: first add files --- lib/sqlalchemy/dialects/mssql/pymssql.py | 138 +++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 lib/sqlalchemy/dialects/mssql/pymssql.py (limited to 'lib/sqlalchemy/dialects/mssql/pymssql.py') diff --git a/lib/sqlalchemy/dialects/mssql/pymssql.py b/lib/sqlalchemy/dialects/mssql/pymssql.py new file mode 100644 index 0000000..84c5fed --- /dev/null +++ b/lib/sqlalchemy/dialects/mssql/pymssql.py @@ -0,0 +1,138 @@ +# mssql/pymssql.py +# Copyright (C) 2005-2022 the SQLAlchemy authors and contributors +# +# +# 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://:@/?charset=utf8 + +pymssql is a Python module that provides a Python DBAPI interface around +`FreeTDS `_. + +.. note:: + + pymssql is currently not included in SQLAlchemy's continuous integration + (CI) testing. + +Modern versions of this driver worked very well with SQL Server and FreeTDS +from Linux and were highly recommended. However, pymssql is currently +unmaintained and has fallen behind the progress of the Microsoft ODBC driver in +its support for newer features of SQL Server. The latest official release of +pymssql at the time of this document is version 2.1.4 (August, 2018) and it +lacks support for: + +1. table-valued parameters (TVPs), +2. ``datetimeoffset`` columns using timezone-aware ``datetime`` objects + (values are sent and retrieved as strings), and +3. encrypted connections (e.g., to Azure SQL), when pymssql is installed from + the pre-built wheels. Support for encrypted connections requires building + pymssql from source, which can be a nuisance, especially under Windows. + +The above features are all supported by mssql+pyodbc when using Microsoft's +ODBC Driver for SQL Server (msodbcsql), which is now available for Windows, +(several flavors of) Linux, and macOS. + + +""" # 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 -- cgit v1.2.3